Installed Self-Grounding 3 prong in place of 2 prong I had a 2 prong plug in place where I needed a 3 prong. (no heavy loads, just TV and such) I read about replacing this with a 3 prong and found out the following:

If the hot end to the box screw registers a voltage, then the metal box in the wall is grounded.
I should use a GFCI outlet if possible in the box.

When I opened the outlet I realized that the box is too small for the GFCI outlet. Instead, I had a self-grounding 3 prong outlet.

I installed the self-grounding outlet, and tested with a circuit tester. The circuit tester lights up normal. However, my contact-less tester beeps on each hole. I also measure the following voltages:

Hot to Neutral - 120V
Neutral to Ground - 0V
Hot to Ground - 120V

Is this normal for a self-grounding outlet?

So you have metal boxes? The findings of 120 V hot to ground, 120 V hot to neutral, and low resistance neutral to ground are consistent with separate ground and neutral paths to the panel and that is almost certainly what you have.

The ground and neutral are supposed to be connected in the panel and only in the panel. If that is what you have, the resistance you measure between neutral and ground at a receptacle is the lengths of neutral and ground wire back to the panel where they are connected.

EDIT

You need to determine that there is a separate ground path (metal conduit or a ground wire) all the way to the panel. The other possibility consistent (I think) with your measurement results is that someone has connected the grounds of the each receptacle to the neutral in each box. I think this is called a "bootleg ground" and it is not according to code and not safe. I think you would see evidence of this inside the boxes.

Time for you to take pictures of the inside of one or more boxes and attach the picture to your question. Also time for one of the experts to comment.

EDIT2

Bootleg ground wiki. You could take off one or more faceplates on receptacles. You could take off the "dead front" on your panel and see if you have ground wires there. Of course, you could be grounded via conduit.


Can I use a US-bought chandelier in India? I am planning to buy a chandelier in the US for my home in India.  I understand the voltage difference (110 V in the US as compared to 220 V in India).

The chandelier uses 60 Watt candelabra bulbs.  So, I was wondering if I can use this chandelier in India with 60 Watts / 220V candelabra bulbs?

If the chandelier is simply controlled by a wall switch (i.e. no internal electronics), it should be safe to do so because you'll be using bulbs that draw about half the current that the wiring in the chandelier can supply: 60 W / 110 V bulb will draw approximately 550 mA from the US electrical supply, whereas a 60 W / 220 V bulb will draw approximately 270 mA from the Indian electrical supply.

However, if the chandelier has an integral dimmer, then it probably won't work with the different supply voltage and frequency.


Can quartz be sealed? If so, would it have beneficial effects? Quartz is not supposed to scratch and is not supposed to stain. Furthermore its not supposed to require sealing (unlike natural stone like granite).

I have what appears to be low quality quartz installed. It both scratches (for example from cast iron pans if dragged over the surface, or even from some dirty cardboard moving boxes that were moved while on the surface) and it stains (rust, coffee, wine, etc). The stains can sometimes be worked out with lots of elbow grease a concoction of cleaners, but sometimes remain deeply embeded. The scratches remain no matter what. The stone is white with grey areas/spots/design and the scratches are the same grey.

Would sealing the quartz help? Could it be harmful?

Incase it matters for any reason the quartz is from the MSI Q series.

I'd suggest finding the local stone supplier (possibly through your local kitchen installer), and ask them.

It sounds like your quartz is more porous than usual is you are getting stains on it - unless you leave wine on it for hours you should normally have time to wipe it up.

Normally quartz benchtops aren't very porous, and so don't take up spilled liquids. This also means they don't take up sealant very well. Maybe your bench will take a sealant since it is more absorbent, but you'd be better talking to someone who can inspect your bench first, or even knows the quarry your stone came from.

I wouldn't expect sealing the bench to be harmful, if using usual stone sealing products.


How can I remove ice damming on my roof? I just noticed that I have a pretty large ice dam forming on my roof (will post pictures later).

I am just wondering, is there anything I can do to remove the ice? It has completely filled the eavestrough on one section of the house.

I have not seen any noticeable warm spots on the roof (i.e. melting regions). We have been having warm, cold, warm, cold weather, followed by snow; which I am sure doesn't help anything.

I understand that to prevent it from happening in the future, would be to better insulate the attic (I also have wooden soffits, which likely doesn't help anything). Next year, I will invest in a roof snow shovel. I think the main culprit has been the stupid weather (melt, freeze, melt, freeze).

Should I just let the ice dam resolve, or should I do something to remove the ice?

It may seem counter-intuitive, but you can simply run a garden hose up there and melt it off. By working from the bottom up you'll be less likely to force water through the roofing and cause a leak.

You don't want to use hard tools on your roof if you can help it. Shingles don't last long when you do.


Adding light to existing outlet controlled by switch Power comes into a switch at my house and the wire is connected to an outlet in my garage. The switch controls both plugs. I want to keep this wiring the same, but add a light out in the garage. Can I add wire to the outlet and connect the light that way? Any diagram/suggestions would be helpful.

If your walls are open this will be easy. Adding a light is legal in my state. With the power off pull the outlet,  add a piece of romex and run up to where you want your light switch, have at least 6" of wire at the outlet and the box connect the new wires to the outlet or pigtail the wires connecting the black hot wire to the brass colored screw and the white or silver colored sctee to the white or neutral wire, the grounds should be pig tailed and then connected to the outlet. Take another piece of wire from the new switch box location to the location you want your light, if this will be a plug in type of light wire the outlet the same as the first (color wise but no pigtails are needed) , now to connect the switch, pigtail the grounds and connect a short length of the bare ground to the switch yoke it should be a green screw, tie both white wires together (wire nut or other listed device) last connect one of the black wires to one screw and the other black wire to the other screw ( if other than a standard snap switch/ or an electronic switch the neutral may be needed).
Note wiring below 8' is supposed to be covered by 1/2" sheet rock or plywood but I have seen so many garages that the wiring is exposed I usually go with what is there. Conduit can also be used to protect the wire and that can be left exposed legally. If the walls are covered it will be a bit tougher but still can be done, you will need old work boxes. These boxes you cut a hole between studs that just barely allows the box to slide in put the wires in the box slide it in the hole then 2 screws tighten the wings or fins depending on the brand. Now turn the power back on and plug in your light. Note a pigtail is a junction of wires that usually has the conductors tied together with an extra piece of wire to connect directly to the switch or outlet. Hopes this helps.


Most efficient way to improve my house's heating I live in the mid-Atlantic in a 100 year old house, and I'm looking for a way to reduce my heating bill.  Last winter, I left the thermostat at 68F, and our gas bills were incredibly high, despite still feeling cold inside the entire time.  I received an energy audit, but, except for confirming the fact that we have no insulation in the walls, it was pretty worthless.  All of their recommendations came out to cost about $25k (after government rebates) and they calculated that it wouldn't pay for itself for 47 years.  Needless to say, I decided to not use their services.

This winter, I hope to make at least one serious improvement to the house to help out with heating efficiency.  Some of my ideas are listed below.  I am wondering which will get me the most bang for my buck, or if there are other potential projects which I haven't thought of.

Add Wall Insulation

The house doesn't have any insulation in the walls.  The plan would be to tear down the walls in select rooms and add fiberglass batt insulation, then put drywall back up.  I am hesitant to use foam insulation mainly because I plan on redoing some of the electrical wiring, and I feel like using foam insulation would wake that very difficult.  Plus, when I take the walls down, I can run electrical lines at the same time as adding the insulation.  Taking down the walls and installing the insulation would probably be a DIY job, but I might hire someone to do the drywall.

I have already replaced the old modly, compacted  insulation in the attic with 6" fiberglass between the ceiling joists, but I could probably add more too.

Replace Boiler

We have a gas boiler that heats water (not steam) for cast iron radiators in each room, but it looks pretty old.  The "Energy Guide" sticker on the furnace says the efficiency is 83.5%.  I know that some more modern hot water boilers have efficiency ratings as high as 95%, so another idea would be to replace the boiler with a new efficient boiler.  I would have to high someone to install the boiler - at least the gas lines.

Replace the Windows

All of the windows in the house are original, so there is a lot of heat escaping through the windows.  Since replacing windows in the entire house is a pretty large undertaking, I would probably just figure out which are the worst offenders and replace them.  This would also be a pro job.

Which of these would give me the most bang for my buck for reducing my heating bill?  Is there anything else I missed?

Replacing the windows with modern double-paned isn't worth the cost; they're not that much better. However, I would recommend looking around for gaps around the windows where the putty stuff has dried out and repairing them. That's a mostly-labor job, and isn't that hard.

In general, your first goal should be to seal any gaps. This is not only much cheaper than buying insulation, but can be done DIY. Look around windows, doors, and vents, as well as any other place where there are intentional holes in the house. These tend not to be done that well, and you may find unintentional gaps.

Is your house on a slab? You didn't talk about the floor insulation.

A new boiler could directly save you roughly 10% on your gas bill, but would be expensive. (You can run the numbers yourself.)


Sub Panel using Sub Feed Lugs We're getting ready to build a detached garage/ADU about 100' from our main house, and have a quick question about getting power out to the building.

We currently have a 320amp service to the main house, with two 200amp panels (Siemens model S4080B1200A).  Initially I wanted to use a 150amp plug on breaker and run 2/0 out to the garage, however looking at the sticker on the panel it looks like the max breaker size I can use is 100 amps.

However looking at the approved accessories for the panel, it lists Siemens ECLK2125 and ECLK2225 for subfeed lugs.

So looking at NEC 240.21 if I'm reading it correctly, I can use the sub feed lug kit to tap off my main panel, run power out the garage, and use a sub panel with a main breaker?

If i do it this way, do I need to size the wire for the 320 amp service coming to the house, or can I still use the wire sized for 150 amp?

My other option would be to use say two 75 amp circuits and two subpanels out in the garage/ADU.  Id rather not do that as it will double up my costs for wire/conduit and panels but if using the sub feed lugs isn't an option, it seems like that may be my only bet.

Thanks!

Your panel's limit on stab ampacity only applies to double-stuff breakers

Your panel's label should read, among other things:

  SUM OF QT BREAKER RATING IS NOT TO EXCEED 110A PER BRANCH CIRCUIT BUS STAB

Note here that it says "QT" breaker, while regular Siemens breakers are type QP.  This is because this restriction only applies to Siemens tandem aka "double-stuff" or "cheater" breakers, which use a type QT label to distingush them from normal type QP breakers, or the type QNR double frame breakers that are used for breaker ratings above 125A.

As a result, I would go ahead and put the 150A type QNR breaker in the main panel in question, using 2/0 Al XHHW-2 for the hots and neutral with a 6AWG bare copper ground in 2" PVC conduit.  (If you're stuck with copper because of local rules, 1AWG is the correct gauge, by the way.)

GO BIG OR GO HOME

For the panel in the ADU, we know two things:

Spaces are cheap now compared to the cost of replacing a panel later because it filled up
We need a main shutoff in the panel since we are dealing with powering a separate structure, but that main shutoff doesn't need to be a breaker (and can't be selectively coordinated with the feeder breaker in the main panel anyway!), just a switch

Given this, I would put a 42-space, 200A panel in the ADU and call it a day; if you don't mind losing a couple spaces, you could even use another S4080B1200A there, provided the panel is living indoors of course.

TORQUE ALL LUGS TO SPEC

There is one final thing to note here, and that is that you will need to use an inch-pound torque wrench or torque screwdriver to torque all loadcenter and circuit-breaker lugs to the torques specified on the labeling.  This is required by the 2017 NEC in 110.14(D), and also is a good idea anyway, especially with aluminum wire, lest you want your subpanel install to be as reliable as Greg Biffle's infamous lugnuts.


Do multiple shower heads require multiple shower valves? I'm working with a home builder to have two shower heads in a master bath shower. The builder proposes have two shower valves, one per head. Is this recommended/required or is the builder just trying to charge me more for another part?

If you don't want both shower heads to be on at the same time everytime you take a shower, then yes you need 2 controls. If you don't care if both head are on, then one control will be fine.


How to prep spruce treads for staining I ripped out carpet for my stairs and there's 2X6 spruce wood underneath.

It's in pretty rough shape. Had lots of staples. Some paint. Some spilt varnish.

My question is are these stairs salvageable, I would like to stain these stairs but they aren't oak. Wondering what I should do.

If it were my stairs and I had the budget for it, I would remove the handrail and balusters, pop the 2X treads and replace them with oak treads. The would eliminate the need to scrape off all the paint at the skirt board area and the clear coat around the balusters. It is a trade off on where the work is done, but in my opinion, it will give a better product once done.

Some of the treads appear to be open on one side, new treads can be purchased with the returns already added, simplifying the install. The new treads can be stained before install, making the finishing easier. The skirtboard at the wall will need to be touched up where the original 2X treads were because the new treads ill be 1/2" thinner. This will also affect the balusters when they go back in, since the handrail should be lowered 1/2" to keep the balusters in the original position. You could simply move them forward, but I feel that would put them too close to the nose of the new treads.

I would also use a 1/4" paint grade plywood to reface the risers as mentioned in another post, and return that with a "stair riser bracket". This would help disguise the end grain of the plywood riser better, by mitering the riser bracket to the new riser covering.

Here is a few pics of a staircase that was carpeted where I replaced the old treads with prefinished treads

I could only find example of stair riser brackets that did not show what i wanted without copyright infringement but a Google search will fill in that part, so I hope.

10-29 edit

This link is for a scraper that will remove the paint along the edges of the skirt boards and in between the balusters. The pros use a still smaller version of this, about an 1 1/2" wide, this is 2" and should still get in the tight places. The wider the scraper the better for a newbie, it will be more stable and not as prone to gouging out on the edges, but still may. A little care at first will help you get past the learning curve. The blade in this one is carbide and is not resharpenable unless you have a diamond stone and that takes time too. You will want to get a pack of replacement blades to get you through the whole task. You could get another type with a tool steel blade that is resharpenable with a file, that is the kind I seen the pros use, then you need to learn how to sharpen them. The replaceable blades are the best choice, unless you know how to sharpen the tool steel type already.

After the edges and around the balusters are done, a random orbit sander will get the rest in the middle. Start with 80G to get the rest of the paint off, then remove these scratches with 120G and make a final pass with 180 or 220G for staining. I would still use the 1/4" plywood for the riser with the return done with a stair riser, a simple one, could even be a piece of lattice to cap the end of the plywood.


What are the major drawbacks of using an electric lawnmower? I have had my gas lawnmower for about 3 years, which isnt very long. It is already spewing oil and white smoke. I know it is most likely the head gasket, but I really dont want to deal with it.

So I am considering getting a new lawnmower. While looking at them I noticed that there are a lot of electric lawnmowers out there. I like the idea because they seem to be lower-maintenance.

My yard is about half an acre, and very flat. The only thing I use it for is to cut grass and mulch leaves. I have read that they arent powerful enough to create a fine mulch, so you have to go over the same spots multiple times. I can live with that.

The other downside I have read about is that battery life can be an issue. People recommend having multiple batteries, but batteries are half the price of the lawnmower!

I was wondering if anyone had experience with battery-powered lawnmowers and how they felt about them. Gas-powered mowers are well documented, so if I have an issue I can almost always find a solution online. I dont think that is the case with electric, but I also dont think there are as many things that can break.

Any suggestions? Thanks.

By far the biggest con is charging battery(ies), although that's becoming less of an issue as battery technology gets better. Any issues with not cutting well, not mulching well, etc are largely issues of older mowers.

Consumer Reports actually starts to recommend some electric mowers as of ~last year. You can read more about their recommendations, but they boil it down to a few points:

Electric mowers tend to cost more up front, but tend to cost less to operate and maintain (by ~$20/year according to their estimates). Payback period is on the order of 10 years, though, making it a long-term investment. You'll want to run numbers using the cost of your electricity and gas for an accurate comparison, of course.
You'll probably want a spare battery (unless you go corded, but those options seem more limited), meaning even more cost. At some point, the battery(ies) will need to replaced as well, potentially eliminating any cost savings compared with gas mowers.
At least right now, there aren't any riding-style electric mowers for large yards. If you have more than ~1/2 acre, electric probably isn't for you.

That said, it seems that the good mowers have good (enough) batteries to last long enough to mow a typical 1/4-1/3 acre lawn on a single charge. You could also go corded and eliminate battery worries entirely.


Can I re-task a large conduit to hold a small conduit and low voltage cables? To revisit our occasional questions on sneaking a low voltage cable into an AC mains conduit...
Suppose you have a fairly large electrical conduit, say, 1-1/2".  You also have some sort of continuous flexible electrical conduit, like smurf tube, where this conduit itself could be fished into the larger conduit.
Can you use the large conduit to contain both of these:

loose low voltage cabling
a continuous flexible conduit appropriate for Class I wiring, and inside that, AC mains wires type THWN.

Is that legal?   Good answers will call out Code cites if applicable.
I am not planning to self-answer this.

Filling uncharted waters
While the use of innerducts (conduits inside conduit, basically) is not completely unheardof (NEC 800.110(A)(3) permits purpose-built innerducts for communications work, which is where they are usually found, and the Code is silent otherwise about "nesting" Chapter 3 conduit types within each other), the problem with any approach that mixes innerducts (whether Chapter 3 or purpose-built) and wires or cables in the same conduit is that there is no clear way I have found to proceed with evaluating such configurations against the fill rules, especially when it comes to the fill of the outerduct, as the 40% fill rule doesn't apply to comms cables.
Unsupported
Furthermore, the conduit support rules never envision Chapter 3 conduits being used in such a manner; for flexible conduits, one could argue that the outerduct forms a "concealed space within a building" that the innerduct is then fished through, as permitted by various exceptions in the NEC, although the wording is not consistent between said exceptions, so the validity of this argument depends on the precise type of conduit being used as the innerduct.
Matryoshka conduit bodies
Another issue you'd run into with this approach is that you'd need to "nest" conduit bodies within each other wherever you had to use a conduit body for a direction change.  This is a problem because it's not at all clear how one'd support the inner conduit body, as required by NEC 314.23, under the circumstances involved, especially since none of the conduits connected to the inner body can support it in that case. (Conduit bodies normally fall under the Exception to 314.23(E) when it comes to support.)
Terminal woes
The final issue comes when you go to terminate this assembly.  If there are no mains wires directly in the outerduct, one could use a bell end fitting for the termination if the outerduct is PVC and the innerducts are suitable for in-wall usage, but this doesn't work if you have to terminate into a box with dividers inside it.  In that circumstance, you have to field-punch KOs into the dividers and run the innerduct into a fitting mounted into the divider, which is not something Code particularly envisions, either.  (With a metal outerduct, one would use a threaded insulating bushing instead of the bell end fitting.)


How can I add 120v circuits to a 240v sub-panel with no neutral? I want to wire my detached garage from a sub panel that supply 240 volts to my AC unit and water pump. My problem is that there is no neutral leg in this panel. I tried bonding my neutral to the ground but that did not work because in addition to having 120 volts when I put my multimeter leads on black and neutral, I also had 120 volts on black and ground. What should I do

You should contact a local licensed electrician.  You should not do what you're  attempting, as it may be a code violation and/or dangerous.

The circuit supplying your A/C and water pump, is likely sized to only supply those loads.  Adding more loads to that circuit will likely overload it, and cause you headaches in the future.

If you want to supply the garage, you'll want to install a properly sized feeder between the main panel and the garage. This may require an additional panel in the garage, and will require properly bonding and grounding in the garage.

If the panel feeder is large enough to supply the garage, and all you need is a neutral.  You'll have to run a properly sized neutral, from the main panel to the subpanel. You cannot use the grounding conductor as neutral.

As it sounds like you're a bit over your head, you might want to contact a professional to do the work properly.

As a side note... In a 120/240V single split-phase system, you should measure 120 volts between ground and either of the hot legs. You should also measure 120 volts between either hot and neutral, 240 volts between the hots, and 0 volts between ground and neutral.


Kitchen sink cabinet size question What is the minimum width I can use for an under-sink cabinet when using a 30" wide cast iron sink?

My off-the-cuff answer is 33" minimum but 36" highly recommended.
But the correct answer is: Get the installation manual for the sink. Usually available online, and if it isn't then contact the manufacturer. The installation manual will show you how much space is needed, particularly how much clearance is needed under each side of the sink, which will vary depending on how it is mounted. Keep in mind that some cabinets will have thicker walls and/or framing pieces under the left and right sides than others.
It is possible that a 33" cabinet might be 1" thick on each side and leave you with 31" of usable space. Combined with a 30" sink that needs no extra space underneath (i.e., it is drop-in and secured entirely on top), you would be just fine. On the other hand, a cabinet that ends up with less usable space (I wouldn't go down to exactly 30" for sure) or a sink that requires mounting brackets underneath the left and right edges will certainly need a wider cabinet.


Is there any reason to be wary of vinyl windows? Consumer reports "buying guide" for replacement windows recommends fiberglass or wood windows over vinyl. I've also heard from various sources that some vinyl windows can warp with expansion and contraction over time.

I'm wondering if I should avoid vinyl replacement windows in general? Do people's bad experiences with vinyl stem from the cheaper end of the spectrum? Do quality brands of vinyl windows exist?

There seems to be a lot of potential propaganda/fear-mongering/crazyness about vinyl windows on the Interwebs. For example here. These websites make my bs detector go off... It seems hard to find a non biased opinion on the subject.

There's an issue to be concerned about in high-crime areas -- they're plastic, so they can melt.  Someone interested in breaking into your place can take a torch, heat up the frame of the window, and push the window or the whole sash in.  Some vinyl windows aren't all vinyl, and have an aluminum or steel core, that might reduce this from being able to happen.

Also, vinyl isn't good for high-heat areas.  A south or west facing window in a hot climate might heat up enough through the day that it'll warp.  This is even worse in dry areas with large high/low shifts each day.

In colder climates, vinyl becomes brittle, which means if you're in a windy area with gets a lot of blowing wind, you could get debris thrown into the window which can crack the whole frame; and unlike other construction, you can't just replace the glass, you have to replace the whole sash.

Vinyl on its own isn't all that strong -- so there's a lot of vinyl involved -- if you're trying to get a lot of light into a room, you'll be able to get more glass into the area with just about any other material.

You also can't paint them easily.  Whatever color they are, that's what they're going to be unless you replace 'em.  This isn't typically a concern for most people, though, as most vinyl windows are white -- but they'll slowly yellow over the years, depending on the exact mix of vinyl.  This is more pronounced in areas with higher UV indexes.  (eg, high elevations with no shade trees)

Vinyl also outgasses.  If you've got someone in the family who's sensitive to chemicals, this could be an issue.

...

That's not to say that there aren't different qualities of vinyl windows, but don't just buy on price -- look at internal metal stiffening, if it's welded or screwed together (you want welded), if it's fully encased in the vinyl (so it won't oxidize), and there's certifications now for vinyl windows ... but I think it's an industry effort, so I don't know for sure how reliable it is.


What distance apart should Elfa vertical wall brackets be? I would like to install an Elfa system in a storage room under the stairs, but cannot find out what distance apart the vertical wall brackets should be placed at. I checked the website but could not find out how far apart they should be.

Does anyone know what distance apart the vertical wall brackets should be? I would like to use their shelves/baskets/etc.

https://uk.elfa.com

The best bet it to locate the vertical bracket right over a stud so that they can be fastened into the stud.

For the maximum holding capacity consider one vertical bracket on each stud.

The system that you want to use looks like it is one that has a top rail that the vertical rails hang from. With the top rail it can be fastened into all the studs that it crosses or if high enough on the wall right into the top plate. With this type of system it can still be an advantage to locate the verticals over studs so that they can be anchored to the wall. Otherwise there is the possibility of the lower ends of the verticals swinging back and forth some.


Should I use urethane spray foam or foam rope for caulking wide gaps? The gaps are irregular around window frame, but the widest are no than half inch (1.3cm) and the frame is flexible metal because the window is uPVC. I can use backer foam that's half inch wide and since gap is deep I can stack them on top each other for tight fit. I haven't used spray urethane foam. Which is better? I also have rope caulk, it's like putty.

Also how does one apply silicone for such big gaps? I have silicone but also the synthetic stuff like Lexel which allows you to reapply without removing old caulk

There are pros and cons to each, making this a subjective question. Here are some comparison points.

Rope caulk is easy to work with. You can take your time and not worry about anything curing too soon. Urethane is potentially disastrous, as it bonds very well to almost anything it touches. Permanently. It cures in a few minutes or slightly longer, depending on environment.
Urethane seals better due to the bond it creates. Rope caulk also seals well, but in cases where size isn't quite right you may have gaps.
Urethane fits a wider range of gaps. You can easily fill narrow slits to voids several inches or more wide. Rope caulk comes in various sizes, but there are often compromises during installation.
Rope caulk is cheap, and you can use it now and later. Urethane foam isn't much more expensive, but you have to use the can in a fairly short time since the nozzle will seal itself shut.
Rope caulk can be removed for repositioning, changes, etc. Urethane would need to be cut and scraped away, usually leaving a residue.

Silicone and other topping caulks would need to be tooled to overlay backer in wide gaps. A combination of putty knives and other items can come in handy, along with a finger.


Is there an easy way to re-attach the end part of a bathroom pull light switch? In my bathroom, I have a light switch; pulling the string that is attached either turns the light on or off respectively. When doing this yesterday, the very end of the pull switch came off - the string is still attached and works without issue, but the very end part (the bit that people usually use to turn the light on/off without pulling the string directly) detached itself. Is there an easy way of either re-attaching the original, or will a new end part need to be purchased?

Those are often held on by a knot, if you can open the doodad (assuming it is simply clipped shut) you will be able to thread the string through the hole and make a new knot. With a needle and thread or some glue you can stich/glue the knot to prevent it from undoing again.

There is no need to replace the string itself unless the string is what failed.


How should I patch a popcorn ceiling? I had to repair a corner joint between my kitchen and living ceiling (kitchen is ceiling lower than living room) by scraping the popcorn off of the kitchen ceiling and replacing a metal corner bead.
The repair seems to have taken and held.  Now, what should I do with the kitchen ceiling?  Many have advised not to try to apply popcorn to that small section of kitchen ceiling - that they will never match.  Should I just scrape the rest of the popcorn off of the kitchen ceiling?  Then what?  Re-apply popcorn, some other texture or leave flat and paint?

No - It will never match the original pattern. But we had similar issues in many apartments where we couldn't just leave a bold spot. So we had to re do that "area"  area being keyword here.

Afterwards apply some undercoats to the area that was redone (we did ours with a concrete mix but some have silicone or other types)

Only you will see exactly where the repair work has been done but trust me. Nobody else will even notice the difference because they would really have to know they are looking for something.

Basically applying a similar patter and repainting the entire area will take the obvious repair work out of eye sight. Just don't tell any body because then everybody will see it.

(That is why I hate doing my own DIY work because I always find something somebody else messed up or the tiny shortcut I took that nobody else ever will even know about)


Safe and low-liability way to determine whether a circuit draws more current than allowed? When I saw several electricians commenting on not knowing of a tool which tests peak current draw from an outlet in this question: "Is the Electrician trying to scam me?", it made me wonder: Is there is a safe and low-liability way to determine whether a circuit allows pulling more current than the circuit is rated for by code without inspecting all of the wires on the circuit?

Note: This question is for situations where someone may have illegally tapped off of a high-amperage circuit to power a lower-amperage circuit and you cannot tell whether the circuit was wired correctly simply by looking at the wire gauge at the breaker panel/box. E.g. If someone illegally splices a wire for a series of kitchen outlets (20A max) to the circuit for an electric range (e.g. 30A).

TL;DR: There is not a 100% safe or 0-liability option to intentionally pull more current through a circuit than allowed by applicable codes.

The cheapest design I can think of is a non-contact clamp ammeter that graphs current clamped to a piece of thick gauge wire. Turn off power to the circuit and then short the thick gauge wire between the outlet terminals. Flip the breaker back on to let it trip and then look at the max current pulled. However, this seems like a huge liability should the circuit pull significantly more current than its rated capacity because it could overheat and either immediately start a fire or pose a potential fire hazard in the future. I personally would never do this and never recommend it since it seems like the test poses too much of the hazard you would be trying to prevent.

The next design I can think of creating also uses a clamp ammeter that graphs current clamped around a wire to a test load. You would create/buy a series of test loads sized to pull just a little more current than the circuit's wire gauge should allow if the circuit is wired correctly and operating normally (e.g. the circuit breaker isn't fault), but not so much as to pose a significant fire hazard over a short period of time. As an example: Use a 5 ohm power resistor inside of a high-heat insulated enclosure to limit current to 24 amps through a 120V / 20A circuit. Similar to the first design, you would turn off power to the circuit, plug the test load into the outlet, restore power, and then remove power if the over-current protection device does not turn off power to the circuit within a second. However, I don't have the data to support that this is 100% safe and it still seems like you could potentially be opening yourself up to future liability as an electrician by performing a test this way. I therefore could not recommend either of these methods or any method that intentionally pulls more current through a circuit than allowed by the applicable codes because there is always some room for liability if you accidentally damage the wiring by pulling more current through the circuit than allowed.


Must a flush-mount panel actually be flush? I'm in California.

I have a flush mount electrical panel. I'm looking to install a second layer of drywall over the existing for acoustic reasons.

This will result in the panel being inset by 5/8-inch. The cover will still for securely.

Is this acceptable?
I know for boxes I use an extension ring but what about the panel?

This is where it does get a little hard to follow things in the NEC so here we go. NEC Article 408 covers Panelboards Part 408.2 is about other articles that apply to panelboards.

So from there we go to NEC 314.20 which covers boxes and a panel is also a junction box. That a flush box must not be set back more than 1/4" from the surface and that's only if the material is non-flammable.

You might try and see if you can find some one who can fabricate a metal extender since I don't think anyone makes one for a panel. The extender would have to be between the exposed wall and slide in external to the panel and secured in such a manner as not to interfere with the panel itself.

You might also check with your AHJ and see if he would grant you an exception but I don't think they would go for it since they are fairly conservative in their thinking.

Sorry for the bad news, good luck.


Avoiding circuit overload with primary + battery backup sump? In a two-pump, battery-backed sump system, how do people avoid excessive power draw when the battery charger and primary pump want to run at the same time?
I'm imagining a post-hurricane scenario: The sump basin continues to refill with water when the grid power is finally restored. At that point, the primary pump and the battery-charger will both want to run at the same time.
I assumed people would solve this by using some kind of intelligent power switch, that only gives power to the battery charger when the primary pump isn't running. But I haven't found anything like that on the market, so I assume that's not a typical solution.
So how do people avoid this problem? Is it as simple as providing as 20A circuit instead of 15A?
(My question is similar but a little different from this one)

By sizing the loads appropriately
Every load has a nameplate or published draw.  You are to use the numbers on the various nameplates to assure that you are not overloading the circuit, or (more literally to Code), to assure you provide large enough circuit(s) for your loads.
You can get any ampacity of battery charger that you want.
You seem to be looking for an electronic solution; that's grossly over-complicated compared to simply sizing circuits (or appliances) correctly in the first place.  But it is permitted in Code, mainly used for "load shedding" to allow an automatic transfer switch with a generator that is too small to pick up all provisioned loads.  You couldn't use that gear here because it is monitoring for sagging voltage or AC frequency from the generator bogging, and that won't occur on a utility-supplied circuit wired with proper wiring.  Unless the wiring is extremely long.
The DC pump is not powered by AC, it is powered by battery.  The AC battery charger which refills the battery, does not need to be large enough to carry the full power of the pump, and it does not have a startup surge. So it might be 2-3 amps, leaving 12-13 amps for the AC pump.


Twin breaker allowance I plan to use a tandem(AKA duplex, slimline, twin, half-height, half-inch, double or wafer breakers) circuit breaker for kitchen.

The 20 Amp Tandem Single Pole Type QT Circuit Breaker ( here is the link to it ) will feed 2 GFCI outlets for countertop.

Now, I ask if is OK this setup. Inspector says that is OK as long the breaker is on dual phases.

Here is her answer: "You can use the slimline product, but it must be on dual phases.They each need a neutral."

What does it means? I couldn't find some info about twin breakers for dual or single phase.

Lost in translation

The inspector is giving you the standard warning not to use double-stuff breakers on MWBC (shared neutral) circuits. Sounds like you fully understand that requirement... and they aren't telling you anything new


What is the third pipe leading to my water heater? Ok here's a riddle. :)
So there are three pipes coming out of this wall to what used to be a gas water heater. The one on the right is the cold water, the one on the left will pour cold water if the sink has both  cold and hot water valves turned on but will immediately stop if either the cold OR the hot is turnyed off. What is this pipe? I am assuming the right pipes are cold in and hot out.
Can the left pipe just be capped off? Does it need to go back to the hot?
Thanks!

Here's my guess. The left pipe goes to the hot water faucet of a fixture with a common hot+cold spout. Since there is no hot water pressure at that faucet, when you open both faucets some of the cold water comes out the spout and some flows backward through the hot water faucet and spills out the left pipe.

The left pipe may also connect to the hot faucets of some other sinks. The center pipe may connect to other hot faucets, or it may be a drain.

If you can't trace the pipes inside the walls, you will need to force something to flow through the pipes so you can find where it comes out. The simplest thing to use would be water from a garden hose, or a hose temporarily connected to the cold water supply in your photo. Trim and smooth the ends of the pipes and use a flexible coupling to attach the hose.


Faux Anodized Aluminum Effect I'm looking for a spray paint that can simulate the look of black anodized aluminum. I will be doing this on wood, the wood is already primed so that there is no wood grain showing. The main problem I have is that black anodized aluminum is not really flat black and it is not really a satin black either, it's somewhere in between. I don't have the equipment to do custom color mixing , any suggestions? Thank you !

My standard "must get this look" finishing advice - prepare several scrap pieces exactly as you have prepared the primed wood, and test the entire finish process on them. Practice makes perfect, and practicing on the final object makes a mess out of it.

My gut guess (and it's a guess, not experience in creating your precise finish) depending on exactly what sort of black aluminum finish appearance you seek would be to undercoat with aluminum paint or light gray primer, and then spray with "transparent black" (or paint with a clear finish with a compatible black dye mixed in.) If trying to match a brushed aluminum look, some texturing of the base coat might help. Steel wool or non-woven abrasive pad after the finish has hardened might help get the surface/shine right.


Switch for alternating between outlets I'm installing a Tesla charger, but I also want to install a NEMA 14-50 outlet so other EV owners can charge in that spot as well, but as it's one spot, both won't be used at the same time. I don't want to have to run two independent lines when only one will be in use at a time. Is there something I could use that would take one line input, and output two separate lines with a toggle switch determining which one is active? And even if so, would such a thing be within code?

You are not allowed to put multiple outlets on a 50A/60A circuit.   You can on a 30A, and that would've been simple, but that will slow charge.

However, your Tesla charger wants 60A and you cannot put a 50A receptacle on a 60A circuit.

Really, the best way to do this is a subpanel.  But wait.

The keystone is a $30 interlock kit made by Siemens for its panels.  This replaces the expensive, huge  Frankenstein switch. The interlock kit straps between two 2-pole breakers, making it so only one can be on at a time.  This is intended for generator interlocks, where the breakers are back-fed, but it's fine to normal-feed the breakers too.  So your cost is

$30 interlock kit
$40 8-space, main-lug (no breaker on the sub**) panel
$18 two 40-60A breakers, $9 each
$5 ground bar

I also got you 4 extra spaces in the panel to use as you please.

You feed the lugs normally, you don't backfeed. The two breakers on the interlock are

a 60A breaker going to the Hardwired Tesla charger, full rate unthrottled
a 50A breaker going to the NEMA 14-50, which is the legal/right way to do that

And honestly, I do not see a reason you can't simply forego the interlock and allow both outlets to be hot at the same time.  The breaker in the main panel protects the wiring to the subpanel and the subpanel itself (which is rated 125A), and the individual breakers protect the wiring to the equipment.  If you try to charge two cars at once without rate throttling, yeah, you'll trip the breaker downstairs.

The feed from the main panel to this subpanel can be any size of wire you please, as long as the breaker in the main panel protects the wire.  At these sizes, there are no brownie points for using copper*, so consider aluminum wire/cable.  For 60A feeder, use #6Cu or #4Al.  For 100A feeder, #3Cu or #1Al at which point you definitely don't need the interlock. (You're allowed to oversubscribe a panel and this won't matter).

* Aluminum feeder does not have the problem that 1970s branch circuits had.  The metal conducts 12x better per dollar. This is why it is widely used on feeder, where the mineral value becomes a significant part of cable cost.

** because it's not needed in subpanels in the same building, a breaker is needed in the main panel to feed/protect the cable run. Getting the subpanel main to pop before the feed breaker doesn't work, without deep-diving into SCADA tech.


How do I get rid of this mould? Can anyone tell me how I can get rid of this black mould?

It has appeared in the corner of our window ledge, as well as all around the bathroom ceiling.

There is no texture to it, it seems very flat on the surface.

You can probably just wipe it off with a bathroom cleaner or some diluted bleach. You should also determine the cause of it, otherwise it will just return. Often in bathrooms it is from a lack of ventilation.


Installing Nest 3rd generation thermostat from Old Trane Weathertron Thermostat (Mercury one) Nest is not detecting Power (Rh) Showing error that power is not connected. Please help.

Installing Nest 3rd generation thermostat from Old Trane Weathertron Thermostat (Mercury one)

New stat wiring:

Old stat wiring:

Nest error:

While you do not state if this is a heat pump unit - the wiring indicates it is..

Your NEST screen shows that Rc (24Volt power for Cooling Circuit) is connected and Rh (24Volt power for Heating Circuit) is not connected, yet in your picture for wiring hook up your red wire is connected to the Rh line (so how does Rc get power and show a connection?). The Nest is either reporting wrong - or you have changed something between pictures.

You can run a jumper across from Rc to Rh since you only have one Red wire. Unless your NEST configuration allows you to to do that through software - if the software does this for you when you select heat pump - I would venture the red they will have you connect to Rc and program jumper to Rh it might aut connect it as well.

You will also need to make sure you specify in the NEST system that you have a HEAT pump unit - this might be a reason Rh does not work and Rc does.

Why you have BLACK X2 to HUM (which I think is humidifier) - I don't know.
X2 is supposed to be AUXilliary Heat and would be connected to W2.

You can see my post here for Thermostat wiring proper color code and also what the individual labels mean - what circuit they are for.


Is there any issue with the neutral and ground being connected in this panel? The picture below shows the electrical panel in a single-family detached home that my wife and I are in the process of purchasing. The home inspector flagged an issue here with the neutral and ground wires being connected on the same bus bars (left and right), suggesting that neutrals and grounds should be separate and (electrically) insulated from each other.

The seller had his building engineer (not a certified electrician) look at it and claims that they cannot separate neutral and ground because the two bus bars are electrically connected through the back of the panel. (A bit difficult to see in the picture, I have not been able to verify myself yet.)

The house was built in 1988 and was inspected at that time. It is located in Maryland, USA. This is the only panel in the home, and it is in the unfinished part of the basement near where I see the service entering the home on the outside. As far as we know, there have not been any issues with the electrical since then.

What should we do? Is this a real safety concern? If you had to (and it is proper to) separate neutral and ground here, how would you do it?

I have done some research on my own, but I am not an electrician. I see most advice is that it's always a good idea to separate neutral and ground except where they connect at the "main service panel". I'm not sure if this is the main service panel or not. I've read some other advice that some systems are designed to have neutral and ground electrically connected like this and it would be a bad idea to separate them in that case. Any help is much appreciated!

May be related to these other questions:

Bonding Neutral and ground in a service panel

Main Panel with separated neutral and ground

Separating neutral and ground in panel

Electrical panel ground issue

Update 2019-10-25:

I was able to get into the house today and get a lot more pictures. This appears to be the main panel: I do not see any other breakers/switches between here and where the service enters the house. There also appears to be a screw bonding the neutral bus bar to the encasement (just to the right of the bus bar on the left). I gather that this satisfies the two conditions specified in Retired Master Electrician's answer below. Here are more detailed pictures of the panel:

In residential services only, you can attach grounding conductors and neutral conductors at on the neutral bus, but it must meet certain requirements. First the main breaker in the panel must be the first means of disconnect from the meter (no separate main breaker). Second the neutral bus must be bonded to the Panel (look for the green screw or a lead going to the encasement).

Any panel after that is considered a sub panel and must have a separate neutral and ground bus.

I will also say that this could change depending on the interpretation of the AHJ. So it's always a good idea to check in with them before proceeding with any argument.

Hope this helps.


What's the most cost effective solution for repairing a slab leak? I live in Phoenix in a 1400 sqft home that was built in 1973, single story, brick and frame.  A few days ago we experienced a slab leak in our guest bathroom, and we're currently entertaining bids to fix it.  However, we're a bit in the fog as far as what our best option is as far as the future health of the system is concerned.
   Currently we've got three options:

Repair the damage, by tearing through the concrete, etc.  Insurance will cover everything (demo and replacement) but the repair itself.
Reroute the hot water line in question through the attic, which will be paid by the insurance company in full.
Repipe the house entirely. Insurance won't pay for this, but I think having them reimburse us for one of the two options above will allow for the cost of repiping to go down.

Our concern is that the first two options will only result in another slab leak elsewhere.  It's in this case where we are entertaining repiping of the whole house, especially if it's going to happen again.  We've got some minor issues that will also be taken care of, like fixing the lines that tap into the irrigation (amateur leaky job) or moving the tankless water heater a bit to allow for a better water filtration set up.

So we'd like to know if the 'one-and-done' expensive solution is the right one, or is it not worth it?

The future health of the system can only be insured by gutting it. However, you're paying insurance; who cares? I don't really know the ins-and-outs of insurance but perhaps you should send them a letter recommending that they do replace the whole system; providing leverage for you to stand on when it breaks in the future and they want to raise your rate after you need to have more work done.

If you do care, then go with the third option after doing the second. Have as much work done, paid for by the insurance company, as possible. Piping into the attic should lower the bid to replace everything else. I wouldn't want to start tearing up concrete as a homeowner or as an installer, where I could just run it above (which your climate permits); much easier and less messy.

If you found this recent leak to be less than catastrophic, ride it out and let the insurance worry about it.
If it was, drop the cash on a new system and sleep better at night.

Ideally you go big or go home (gut it). Otherwise however, I cannot quantify what your piece of mind is worth to you, and what possessions are at stake.

Bottom line: the most cost effective solution for you and the insurance company is to only repair what's necessary, provided you're not looking at a rate hike and don't have any Picasso's hanging on the walls.


Necessary to sister joists in skylight frame? Piggybacking on my previous question about the headers in a skylight frame (Double header for skylight frame), I'd like to know if it's required to sister the uncut joists on either side of the skylight well?

As a reminder, my ceiling has 2x6 joists 16 OC.  And the flat roof which is 20" above the ceiling has 2x6 rafters 32 OC.  There will be no cuts made to the roof rafters.

If you have the opportunity to double them up, then sure...more is more. Otherwise no, it's not required as you're only carrying one rafter and not creating a dormer, which does indeed require double or more for the end rafters.


P trap for 2 drains? I am remodeling my bathroom and hopefully move my washer dryer. my goal is to share the new shower drain with the washing machine drain. do i need 2 separate p traps or can these 2 drains share a p trap.
thanks

Under IPC (and probably other codes) anything other than "a double sink" with various short distance restrictions on what constitutes that requires its own trap.
https://codes.iccsafe.org/content/IPC2018/chapter-10-traps-interceptors-and-separators
1002.1 for the detailed language, but the short and sweet is you might be able to share a vent, but each needs its own trap.
Furthermore (under UPC, apparently not a problem under IPC) you are not allowed to put a laundry P-trap under (or within 6" of) the floor, which would work against sharing with any normal shower drain.


Are all these duct taping on my furnace normal? I just bought the house, and I saw these duct tapes on my furnace in the basement (I guess it's not exactly a furnace, but also an air ventilation system since it's turning on in summer). Now what are all these duct taping? is this normal, also should I retape them since they have mostly came loose, and cold air is blowing out of the holes.

Perfectly normal sealing of penetrations by wires. Looks like a first rate installation.

BTW you have a tee fitting on the condensate line which is well placed to allow cleaning of the line to clear it of algae or wet dust. Many pretty good installations do not have this feature (mine doesn't). It seems to me that you should gently insert a rubber stopper in the open end. This would prevent something falling in and would reduce leakage of air out the condensate drain. At the very least put a loose cover over it to prevent something falling in.


Proper grounding and service wire choice for remote load center, RV pedestal I'm setting up a trailer pad at home and will be running service to a load center for the trailer and additional power to back yard area (about 100').  My only question to resolve is the proper way to set up the ground at the load center pedestal.  I'll be setting up a 50 amp 240v service using this panel https://www.amazon.com/gp/product/B00A8FQUYW/

If I read the comments below by these experienced electricians correctly  then

I should bury an additional ground conductor (ECG) i.e. a 4-4-4-4 and not bond the neutral to ground at the load center but connect ground of load center back to the main service panel with the additional conductor.

I wonder if in additional to that it would be prudent to set a ground rod at the pedestal and tie that to the same unbonded ground of the load center as well.  Or is that overkill or simply ill advised?

If you have some experience with this issue would appreciate your thoughts.

  Jim, Take a look at 551.76. RV Pedestals SHALL BE GROUNDED by a
  continuous EGC run with the feeder conductors for the pedestal row.
  551.76 (C), The neutral SHALL NOT be used as an EGC. Having said all of this, ground rods at each pedestal would not be required, however
  after much investigation, in California for some reason, the AHJ wants
  ground rods at each pedestal and NO EGC run with the feeders. No
  matter which method is used, the neutral is not grounded or bonded at
  the pedestals.

  Name: Wayne Foster Email: hurk27@attbi.com Location: Indiana Title:
  Electrician In Trade Since: 1976 Registered: Jan 2002 Total Posts: 768
    posted November 15, 2002 at 01:12 AM       Edit/Delete Message "the
  AHJ wants ground rods at each pedestal and NO EGC run with the
  feeders. No matter which method is used, the neutral is not grounded
  or bonded at the pedestals."

  Talk about a dangerous setup if a appliance were to go to ground the
  earth would not provide a low enough impedance path to trip a 5 amp
  breaker!!! and the whole RV would be hot to earth!! could you imagine
  what would happen if a elderly couple touch the door and fell dead.
  guess whoo they would go after? the installer not the local AHJ.

  80.29 Liability for Damages. Article 80 shall not be construed to affect the responsibility or liability of any party owning, designing,
  operating, controlling, or installing any electric equipment for
  damages to persons or property caused by a defect therein, nor shall
  the _____ or any of its employees be held as assuming any such
  liability by reason of the inspection, reinspection, or other
  examination authorized. ```

The answer is "electrician in trade since 1976". In 1976 a 3-wire groundless connection was legal. Certainly not today.

Even a 1976, a separate neutral and ground wire was an improvement. He made it sound like the AHJ would prohibit it, seems unlikely.

Today, belt and suspenders is mandatory. All sub panels must have ground and neutral brought separately, with separation in the sub panel. And then, an outbuilding or other off site location needs a separate ground rod.

And unless the ground rod tests to 25 ohms, it needs two ground rods. Unless you have the equipment, testing is more expensive than driving a second ground rod.

If you're in conduit, use THWN or XHHW. It's cheaper.

if the conduit run is continuous, don't choke cable down it, use individual THWN or XHHW conductors. Your neutral can be smaller and your ground can be much smaller.

For instance I just priced 2/2/4/6 in XHHW and it was $120 for 100 feet.   I don't see any 2/2/2/4 URD or anything out there at that price.

Mind you I got these prices by calling my local electrical supply house: trying to buy wiring on the Internet doesn't really work. Too many prices are sucker prices, or lowball but "gee, we're out of stock but thanks for joining my email list" prices, and then there's shipping to contend with. There is also junk imported from far-east places that use US wire sizes.  You don't want that. US big-box stores don't have any selection.  Proper electrical supply houses aren't online, these things have a very low price-to-weight ratio, so selling online is a fool's game.

Why URD is not a good fit for feeder

Feeder, service lateral and distribution are three separate and different things.  Your location is on your side of the meter, which makes yours feeder.

Power companies follow a completely different and more liberal code.  They are allowed to use AA-1350 aluminum, it was designed for power transmission and distribution after all!  URD is intended for distribution (pole to pole) or service lateral (pole to demarcation point which is before the meter) and that is abundantly clear:

from product descriptions (which say that plainly, even if many don't understand the terms and so, disregard them)
product brochures (note the truly screwball ampacity ratings, and footnote that "by the way" these don't apply to NEC usage which must come from NEC's tables).  This is glossed over because product users are expected to know it.

Now if you selected this cable because of these wild ampacity ratings like 120A for #4, that doesn't work at all. You need to use NEC rules for determining ampacity. For instance #4 Al has the same ampacity as #6 Cu, only good for a 60A subpanel.

So why does groundless 2/2/2/4 URD exist? For service laterals for three-phase wye service, hot-hot-hot-neutral, either wye or wild-leg delta. Why does Home Depot sell it? Because it sells.  Given how bad their help is, I'm sure a lot of what they sell is misapplied, or wasted when the inspector catches it.

Also, the cable does not have a ground wire.  People look at the yellow striped smaller wire and go "that's the ground because yellow is kinda like green". No, it's the neutral.  It's legal to remark #4 or larger wires, so it would need to be marked with green tape to make it a ground, and a hot conductor would need to be re-marked with white tape to be neutral.   I bet almost nobody does that.

A fair bit of googling reveals many claims that URD is not legal inside any home.  The claims are that NEC doesn't mention URD so it's not a proper wiring method.  That does make sense.


Fixing a sagging foundation We are currently renting our house and considering purchasing it from the owner, but it is sagging, and in some rooms it is rather significant and noticeable, with the worst parts being approximately a 1" rise in a 24" run. It has apparently been this way for a while, as all the owner's trim work has strange angles cut to fit the shape of the house.

There is a thick beam in the basement, probably 6" by 6" or greater, that crosses the entire house and supports all the joists. A four foot section was removed to put in the new furnace. I'm not sure if this cut is the reason the house is sagging, but I'm wondering if this amount of sagging is something to worry about, if we should look into fixing it and how hard of a fix it is likely to be, or if it's strongly suggested that we find another place.

A 1" to 16" slope is huge.  that would mean a 10 " drop in apx 13 feet.  Did you mean 1" in 16 feet?  Regardless, the fact that you are asking the question indicates that you need a professional to take a look.  There are many possible reasons from maybe the cut center beam, collapsing or crushing support posts(top or bottom), settled footings, etc.  This is a common situation in very old houses, especially ones built on stone foundations. A simple answer would be to jack and support the offending beam(s) to restore a level floor, *however*several other factors need to be considered before jacking can be done. Factors like chimney/roof coupling, door and window reactions, tile floors, millwork/trim, plumbing connections........the list goes on. Find a competent general contractor that has experience  working on older homes. That person should be able to determine the root cause, then formulate a plan to fix the problem. To buy the house or not might be determined by the repair costs and advise this person gives you. I would also have a complete home inspection done before even considering making an offer to buy this house.


How can I keep a rug from moving? Not sure if this is the right place for this question but....

I have a rug that is about 15x20 feet.  My problem is that every three weeks or so I need to take everything that is on top of it (coffee table, couch legs, entertainment center etc) off and straighten it out because it either gets tilted in such a way that it doesn't line up with the walls any longer or bunches up in the middle at certain spots.

Does anyone know of a way to keep it from moving around?  Is there something I could use to attach it to the carpet below (without damaging the carpet)?

They make rug pads just for this:

You can find them at any big-box home improvement store.


Is it OK to have a GFCI downstream of a standard circuit? I would like to extend a standard electrical circuit to the outside with a GFCI outlet. Can I install a GFCI downstream? This would be easier than running a new circuit back to the breaker panel.

Yes you can certainly do this. Other options include replacing any outlet upstream with a GFCI, or replacing the breaker with a GFCI breaker. In both these cases, the entire circuit would be protected.


What could cause radon levels to be higher on the 3rd floor than the 1st and 2nd? Details:  It's a 3 story building.  Each apartment has its own HVAC system.  There is no shared ventilation system.  The foundation is a slab.  The radon levels on all three floors were measured simultaneously.  The first floor was 7.3 pCi/L.  The 2nd floor was 6.7, and the 3rd was 9.2.  Each measurement was in the same horizontal place, near the center of the building.  It was done when the weather was cold enough to be sure all windows were likely to be closed.

Other tests have had similar results, but were not done as rigorously.  E.g., not simultaneously, not in the same part of the building, etc.  The results vary a lot with the weather and probably other factors.  But it doesn't seem logical that the 3rd floor should ever have higher levels than the other two floors.

4/12/2016 ETA:

Tester101 asked if there is a radon mitigation system in place.  How would I find out?  What does a radon mitigation system look like in a 3 story building?  In other words, even if I saw one, how would I recognize it?  Can I recognize it by something coming out on the roof?  What would that look like?  What would the difference be between that and ordinary vents such as drain vents?

Is it likely that a radon mitigation system could be malfunctioning and dumping radon onto the 3rd floor?

I read somewhere that people don't have to worry about radon on 3rd floors and higher because by the time it gets that high its levels are drastically reduced.  But that contradicts another answer to this question, which implied it would be normal for the levels to be higher depending on ventilation etc.

I also read somewhere that if the levels aren't lower on higher floors, the radon could be from building materials instead of coming up from the ground.  How could I tell if that's a factor here?

Those are some high numbers, 4-pico's is the standard "something needs to done" threshold. But, the difference in readings has to do with ventilation & thereby natural convection.

All air will rise or be drawn-up in a 3-story building, drawing is what's happening with the 2nd floor's lower readings & they're being added to the 3rd floor. Additionally, this rise or draw is magnified when exhaust fans are used or windows & exterior doors are opened.

It's best to treat or remove Radon at it's before it enters the structure so the entire structure is then cleared or reduced of Radon levels. However, this could result in more tenant turnover & higher rents...I'm just saying (I'm joking).


Suspended platform hanger support spacing calculation I am building a 8' x 4' storage shelf that I would like to hang from my ceiling. The frame of the shelf is constructed using 2" x 4". I have 2 x 4 cross supports every 24 inches. The shelf attached to the frame is a 1/2" OSB board.

Can someone help me determined how many hanging supports are needed to hang this from the ceiling. I am not sure of the calculation to figure this out. My plan is to suspend this with 3/8 threaded rod which will couple with a 3" lag screw. I would like to be able to support 600lbs.

You want to support the equivalent of 18.75 lbs per square foot which is a relatively a lot of load compared to what your ceiling is designed to support. You will need to reinforce your ceiling or provide an alternate support structure.

You need a minimum of (4) supports for it to be stable. Supports at each rafter or joist will spread the load better.

There is no hardware that couples threaded rod with a lag screw.


What adapter do I need to connect Mr. Heater F273704 to a LP gas tank that has Not knowing that this is something I have to pay attention to I bought this hose
https://www.amazon.ca/gp/product/B001CFWF5U/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1
The right side of the hose is fine, the left side connector does not match the gas tank connector (my understanding is that the hose is POL make and the tank is Type 1 female)

but my propane tank takes this

What adapter or combination of adapters do I need to be able to connect my MR Heater heater to my 20 LB propane tank?

The left-side connector on the upper hose is called POL. The connector on the lower hose is called ACME or type 1.

Have you tried the POL hose yet? I have not yet met a propane tank that accepts the ACME/type 1, but was not also compatible with the POL. Look into the valve on your tank. If it's threaded on the inside then the POL will work. Don't forget: the ACME uses a right-hand thread (rightie-tightie) but the POL uses a left hand thread. In other words POL must be turned in the "loosen" direction to tighten it.


Installing framed sliding shower doors Just wrapping up my porcelain tile install on my 32x60 shower. I am installing framed sliding shower doors and was researching ahead for that. There are 3 screws installed in each vertical side. The screws provided are 1/8"x1 1/2". The instructions say to use the anchors provided, however when framing out for my shower, I installed studs right where these are going to go. What's the best way to go about doing this and are these screws sufficient? Obviously I won't be anchoring with the studs. 1 1/2" will barely make it through the track, tile, and Hardiebacker. I'm assuming these are meant to be used due to the anchors, so I should look for something longer? Also, I suppose I should predrill 3/8" holes through the ceramic with a diamond bit, huh?

You will be fine with the 1 1/2" screws. If you think about your install it's exactly what the manufacturer expects (99% of shower doors are tile over hardiebacker). That said if you are bothered there will be no harm in using longer screws with the same diameter.


Fitting for cable entry to home? I need to make solar PV cable enter my home, horizontally through a hole in a wall. There are four insulated wires in two separate 1" conduits but there is one hole through which they must go in.

Is there some electrical fitting I can use for this entry, to cover the hole and make it look proper? I was thinking of attaching a junction box. No building codes apply where I live.

Edit: Here is a picture as requested. Currently there is only one conduit but there will be two. Also the conduits can be made to come up form the bottom.

There are a couple of simple solutions. One would be a simple PVC raintight junction box. You would drill holes for the 2 conduits coming in and one in the back for entering the home. Use the right sized male adapters.  Be sure to caulk where it enters the home, esp. if subject to weather. If subject to severe weather you might look into using rain tight fittings (yeah, I know, nothings "really" rain tight, but we do our best).  You could also use an entrance ell (tee type) that has can accomodate 3 conduits.


Confusing ceiling light fixture wiring I have a new LED ceiling light fixture that I got to replace an old T12 fluorescent light in our kitchen which stopped working. After turning off the breaker, verifying that there was no power to ceiling fixture with a voltage pen, I removed it noting that it was only connected to a black wire and a white wire in the ceiling box.

New light has white wire, black wire and a ground wire. I connected the white wire to white and black wire to black, but am now stumped on where to connect the ground. The LED does get voltage as the no-contact pen lights up when I switched the breaker back on (yes, I was careful not to touch the fixture when it did that).

I've enclosed pictures of the junction box (1st & 2nd pictures) as in there I see a white wire spliced to a black one (red wire nut), plus on the right side of the junction box are what looks to be a black wire and a dark brown one - unless that's just discoloring from age - wrapped in some black cloth tape (orange wire nut).

Tell me what I'm doing wrong and thanks in advance for any help.

The cable entering from the left is just old wire whose marks have faded or was never polarized in the first place.  I'm not worried about that. Pretend one is white and one is black.

The box is entirely ungrounded and the old Romex cables do not have a ground wire. Again, not worried about that.  Just leave it dangle.  It's not that I don't like grounds, this is just a pretty low priority as it's unlikely to be touched by humans, and is probably going to be in a GFCI envelope anyway.

What concerns me is it doesn't look quite right for a switch loop.  It looks like there's only one wire on the orange nut, which us weird. Which makes the red wire nut seem superfluous.  Just rubs me wrong is all.

Nonetheless, the worst mistake you can make is take apart wire nuts or wires other than the two conductors (and ground if present) that directly lead to the old lamp.

Are you sure you didn't pull a wire out of the orange nut and put it back on the red nut?  Does the switch still turn the light on and off? does power enter this box even with the switch off? Was there ever a second light location also controlled by this switch?


The new GFCI outlet is not working! I live in New Hampshire, U.S.

I am trying to add a light and a GFCI outlet in a bathroom.

I have a GFCI outlet in the line first from the source.  The outlet and switch are in the same double box.  The switch and light work fine.

From the GFCI outlet running to another outlet receptacle in the kitchen.  Both outlets are not working.  I connected the wires running to the other outlet to the GFCI outlet load screws and this should work but does not.  Any ideas what may be wrong?

With GFCIs, the rule is "one step at a time".

Disconnect the GFCI except for the ground wire.   Tape or cap the dangling wires.   OK, assuming you want the light not on the GFCI,  does the light work?

Now connect only the LINE side of the GFCI.   Does that work?  If it fails, how?   If it's just dead, it's a bum GFCI and go get a good one from a better store.  There's a reason electricians don't buy from big-box.

Ok so it all works.  Now hang the remaining outlet(s) on the LOAD side of the GFCI.  Generally this means attaching exactly 2 wires from 1 cable.  If any problems arise, you know what it isn't.

Watch your neutrals.


Partial power outage ,facing single-phasing My short name:Teza, we have had partial power outage in our house since months ago.

First we would hear a short chirp sound then we would see flickering of some light bulbs, then power would go out, no current in receptacle outlets and no lights in garage and front yard light and in the kitchen and some light bulbs in the living room would go out and refrigerator would stop working.

By making effort, it happened I found that after I hit turn/on touch wire of oven or cooktop then power would come back on.

This issue continued until I checked the kitchen GFCI it was not good I replaced it the issue remained I disconnected our old Fire Alarm System (installed on garage wall with its four blinking led indicators). Also I started to check loose socket bulbs and I disconnected some wirings of lighting to minimize areas of inspection, I also used multimeter to test circuitry voltages.

By all these test/checking and actions from days ago the problem of flickering lights was somehow lessened and chirping sound of alarm stopped. The frequency of this nuisance that was almost ten times during day and night became to two or three. My searching results are the culprit might be:
 1. Short circuit
 2. Circuit overload,
 3. Ground fault.

My question is which one of these 3 areas could I refine my inspection.
One area that I suspect is the transformer in the attic which would supply 12 volt power for Fire Alarm System, I think circuit a short has occurred inside it ( with mili Amp currents).

I should add here that in some occasions I had to go out to flip the circuit board kies to bring back the power. That unit as well as Electric Meter unit are old, and our property has been built around 30 years ago.

Could anybody advise and help me find the fault(s) by more pinpointing?

Key question: Where are you (country/region)? If you are in the US/Canada or another area with 120V/240V power - i.e., "regular" receptacles & lighting are 120V but a few large appliances (cooktop, oven, dryer, etc.) are 240V then you may have a "lost leg". This is a very serious problem. The key reason I suspect this type of problem is:
after I hit turn/on touch wire of oven or cooktop then power would come back on.
That indicates a correlation between having 240V loads and other 120V circuits working. That can happen if you have a lost neutral or some other serious problem.
Call Your Electric Utility and tell them you have an Outage
The good news is that very often this is a Utility Company problem. Call them and tell them you have think you have an outage. Specifically a lost leg or lost neutral. They will (at least in the US) come out pretty quickly to check things  out. Most of the time this will turn out to be a problem on the utility's side - e.g., wire from pole to meter - and they will fix it at no charge. If they determine it is not their problem then you will need to get a licensed electrician to check things out.
As a very basic test, you can use a multitester (voltmeter) to check the voltage. In a normal receptacle it will be ~ 120V. If it varies significantly (more than a few V) and especially if 1/2 the receptacles read very high and the other 1/2 read very low or if the voltage varies significantly when you turn on/off the oven, cooktop or other 240V loads then you almost certainly have a lost leg or neutral. The only question is whether it is the main panel (electrician) or outside (utility).


Installing a ceiling light and rewiring switch and outlet I have a bedroom that has no ceiling light.  The bedroom is on the first floor, below our living room so there is no access from above.  There is also a light switch that controls an outlet.   I would like to install a ceiling light, controlled by that light switch and rewire it so the outlet is no longer controlled by the switch.  The switch is not directly in line with the desired  location of the light, so at some point I will need to go through a ceiling joist or a stud in the wall but I am not sure what is my best option.  As a novice who has no electrical experience beyond changing out bad switches/outlets and simply rewiring them the exact same way I found them, I would appreciate as much information as possible on this.

1. Remove the existing switch box
This may require you to cut the nails/bracket attaching it to the stud.  You should be able to accomplish this using a hacksaw, oscillating multi-tool, or any other thin bladed saw.
2. Get a flexible drill bit
They can be a bit expensive, but you're going to need one if you don't want to remove the drywall. I recommend getting the whole kit, which includes the alignment tool. It will also come with a tool for pulling cable, which might come in handy later.

3. Cut the hole in the ceiling
Use a drywall circle cutter, hole saw, jab saw, utility knife, etc., to cut the hole for the ceiling box.
4. Drill up from the switch box
If you're lucky, there'll be no fire breaks in your way. If there are, you'll have to drill through them as well.  Use the alignment tool to get the flexible drill bit to the middle of the top plate, making sure the bit is straight and plumb (you want to go straight up through the top plate(s)). Keep in mind that it might be a double top plate, so it might take a bit longer than you'd think.
NOTE: The drill bit has a little screw on the tip, so it will basically pull itself through the wood. You're not going to have to apply much pressure, just let the bit do the work. If the bit gets bound up, you'll have to reverse the drill to get it to back out.
5. Bore through the joists
Position the flexible drill bit up through the hole in the ceiling, so that it hits the joist a couple inches up from the ceiling. If you're only drilling through a single joist, being perfectly straight isn't that important. However, if you have to drill through more than one joists, you'll want to make sure that the bit is positioned as straight and level as possible.
If you have to go through more joists than the single bit can reach, you'll have to buy extensions to lengthen the bit. Another option is to cut additional access holes along the route, so you can drill from multiple locations.
6. Fishing the cable
This is the most difficult task, and might require cutting strategically placed access holes through the drywall.  Basically, use any means necessary to fish the cable between the switch and the outlet. The flexible drill bit can double as a fishing rod, and can be used with the cable pulling tool to pull the cable.
You might want to consider buying a fish tape and/or fish rods, as they'll make the job more manageable.

NOTES:
If you want to control a light and fan separately, you'll want to pull three wire cable (hot, hot, neutral, ground), instead of two wire cable.
The current switch box is too full, so you'll have to install a double gang box to accommodate the new wires and switches.
To make the receptacle always hot, simply connect the line going to the receptacle to the feeder coming into the box (hot to hot, neutral to neutral, and ground to ground).
Make sure you use the proper gauge wire.  If this is a 15 ampere circuit, use 14 AWG copper conductors. If it's a 20 ampere circuit, use 12 AWG conductors.  Check the breaker protecting the circuit, to determine the circuit ampere rating.
Make sure you turn the power off at the breaker, and verify that it's off, before beginning any work.
Make sure you install a ceiling box rated for ceiling fans, preferably one of the braced boxes.
Do your best to be sure there's no other utilities in the way, before drilling through joist.  You don't want to hit a pipe, other electrical line, etc.
If you have carpeting on the floor above, you might consider pulling back the carpet and opening up the floor.


What types of tile require a wet tile saw? I have tiled with all kind of tile in the past. When redoing my kitchen I custom ordered hand painted tiles to match the odd color of the granite. So I only had enough tiles for the project without breaking a single one. So I decided to split the two evils and rent a table saw. When everything was said and done I tried to manually cut one of the tiles to see if it could be done without chipping the finish. To my surprise it worked fine.

The question is this. Are there any guide lines for cutting tile without a table saw, and instead using a manual saw with a guide? For years I have cut plain white tile with a hand saw and I get perfect cuts every time, but for something like terracotta I get chips. Also are there any procedural steps that work better for some tiles than others, for instance when cutting a thick tile, I use a hack saw for the first cuts into the finish, then switch over to a true tile hand saw to handle the "meat" of the tile. In this way the finish and features on the tile remain unchipped.

For cutting porcelain or ceramic tile, standard practice is to use:

A wet saw with a diamond blade
A manual tile cutter (a carbide wheel slides along a rail to score the tile, then you snap on the line.
Tile nippers for complex shapes

You can use a diamond blade with a hacksaw to cut holes, but it won't be very efficient.

If you have mostly straight lines, you can get away with a decent manual cutter and perhaps a pair of nippers. A wet saw makes the job go faster, but is not necessary.


What is the minimum height for garbage disposal drain above the drain stub Apparently the garbage disposal drain must be above the drain stub, but I can't find a clear answer for how much height difference is actually required.

Let's use this drawing:

The question is how much higher does the disposal drain (#1) have to be relative to the drain stub (#5)?  I've seen answers ranging from "just above it", to 1 inch, to 4 inches, so what's the actual minimum I can get away with?

Also, how do you measure it?  Is the important measurement going from the bottom of #1 to the bottom of #5?  Or from the bottom of #1 to the top of #5?

I don't think there's a code imposed minimum, but there's likely a physical limitation based on available fittings.

Between the disposal outlet and the drain, there must be a trap.  The bottom of the disposal outlet, must be above the trap weir (the point in the trap at which water starts to drain from the trap).

Therefore, in theory the bottom of the outlet has to be just slightly above the bottom of the drain.

In reality you'll have to use available fittings, so the minimum height would be based on what the fittings physically take up. Bare minimum, you'd exit the disposal with a 90° elbow, and connect directly to the top of the P-trap.  So whatever height is taken up by the elbow and P-trap, would be the minimum.

  WARNING: I have not searched through plumbing codes, so I could be wrong about a minimum height not existing.


How can I find the hollow cavities in a concrete block wall through stucco? I am going to install heavy wall cabinets to a stucco covered block wall. After much research, I decided that the best attachment would be with toggles (Snaptoggle). However, since stucco covers the block and hides it's outline, finding the hollow portion to insert the toggle is almost impossible without drilling a multitude of exploratory holes. Anybody have a better method for finding the hollow portion?

If you are looking for hollow cells, as opposed to filled reinforced cells, I'd use an infrared heat detector. It will expose both vertical and horizontal. (By the way, some concrete blocks are 12"...used as pilasters, etc.)


How to repair damaged outer insulation on non-metallic cable and BX? While doing some work inside my basement ceiling I discovered a small tear in the outer insulation on a Romex cable, and similarly a cracked open BX cable (outer armor slightly unwound for one turn).
I'm the homeowner, and both of these are existing circuits.  In each case (Romex and BX) what is the best thing to do? What is the easiest thing to do that would be acceptable even if not best?
There is no damage to the inner wire insulation, paper, nylon strands, or other components of these cables.  Only the outer jacket.
I could

leave them alone
tape the romex or use a patch kit, and add staples on both sides of the patch
run them through junction boxes without cutting them, just put the damaged bit inside a box as is.  I'd have to modify the box to get the wire inside with strain relief and without cutting it
cut them and add junction boxes.  I'd have to cut them twice and add two boxes with. splice between and all this would be buried in the ceiling
rip it all out and run it again.  I could do this for one of them because it runs entirely in the basement ceiling.  This would be a full-day job.   The other one runs into a wall upstairs so it's not even an option.
I saw on another post there is an $8 Tyco splice kit for Romex (but not for BX).   Given the damage is limited to the outer plastic jacket, is that really any better than wrapping it (the Romex) and stapling it?
any other solutions?

As others have pointed out, you aren't allowed to modify a box as you propose in option 3, but there are open splice boxes for this purpose.  These are designed for enclosing illegal bare splices and made with slots instead of holes, so you could slide the damaged NM cable in without cutting it.  Here's an example of one: https://www.garvinindustries.com/54171-opr

I'm unaware of a version for BX.


What is the difference between MSS SP-80 Type 1 and Type 2? I have a bronze gate valve whose spec sheet says it conforms to MSS SP-80 Type 2.  However, the project standards specify that the gate valve must be MSS SP-80 Type 1.  What is the difference between the two types, anyway?

FYI, the spec sheet for the particular valve in question can be found here.

It seems a Type I is a globe valve and the type II is an angle valve.


Should I insulate my basement ceiling? I recently moved into a house where the previous owner built an extra room on the back of the house, and expanded the basement underneath that.  The addition room is noticeably colder than the rest of the house.  Using an infrared thermometer I discovered the floor of that room is about 4-5 degrees colder than the rest of the room, as well as the floor of other rooms.  Should I insulate the ceiling of the basement below this room?

What type of heating is used in that added on room? That will make a difference in how you solve the problem of the room being cooler than the rest of the house. Answer #1; yes insulate the floor if the basement under that room is unheated or cooler than the rest of the house. Answer #2; If the added room has 3 sides exposed to the weather, that is probably 1 or 2  more walls than any other single room in the house. If this is the case the room should have been built with more insulation than the rest of the house, since it will loose more heat due to the number of walls exposured. The type of heating system will determine how you correct the heating deficiency. You may have to add a separate heating device to solve the problem.


Regulations 2015 NEC regarding 12/24 volts DC, New DC wiring Light/+in my old." I'm Scared " What might regulations would there be in the 2015 national residential electrical code regarding 12/24 volts dc in residence.

I want to install mostly lighting but also also all electronic devices using boosters and regulators per devices as needed.

I could only find out that 25 volts and lower are not regulated and higher voltages regulated diferant.

What scares me is the 2015 electrical code regulations Preventing DIY 24 volt system in my house. If around so much money just to ask a question here.

Can anyone help with this? Thank You, Jon.

Thank you all for commenting on my questions.

I've not been able to find rules regarding a 24 volt DC power systems for a residence in any year of  NEC books but I'm nut sure what to look for.

I just want to install a 24 VDC system to direct power LED Lighting and other devices.

Jon,

First of all, I want to make a couple of points,

A home owner can do any wiring or electrical on his own home so long as he is not actually tying it into the power grid and he does it up to code.
Most of the codes are common sense so it is really easy if you step back and use your head.
There is no reason to be scared, a system like you are talking about is not too hard and if you have any questions, pretend like you are working with 120vac and you will be fine.
I know that this post looks long but take it chunk by chunk and if anything is unclear then please comment and let me know, I'll be happy too edit it and help you out.

I want to start off by making one distinction. There are many kinds of "current limited circuits" that have very little regulation. These can include communication wires, signaling wires, and equipment like that. It can cause some confusion because these circuits are entirely different than what you are talking about. If you have enough power availability to run lights, then it doesn't qualify as being intrinsically safe.

Articles 720 and 411 of the NEC are the main sections that have the rules specific to these systems but there are a lot of regulation that still applies (I mention some of it below). Article 411 (found here - freenec.com/T254.html) deals specifically with lighting at 30 volts or less. Article 720 found here - freenec.com/T590.html) deals with everything at 50 volts or less.

One interesting thing to consider if you are using batteries is that a 24V bank will normally reach a maximum of 26-28V during a normal charge but during a special charge called an "equalize" charge, it can reach up to 32V.

I am when you are working with any low voltage ( ≤ 30V and ≤ 50V) it falls under the same regulations as high voltage in regard to circuit and wire protection. For example, you need current regulation (breakers, fuses, or advanced circuit protection) because even a "harmless" 12v car battery can provide enough amperage (current) to become a hazard if it gets shorted.

It also falls under many of the same regulations in regard to grounding. You don't have to ground either leg in DC systems, however, you do need to have a ground wire whenever you string the DC wires. If you don't ground either leg (ie positive and negative), you need too use a DC fuse (or DC breaker) on BOTH legs wherever you need circuit protection. However, if you do ground one leg (you can ground either the positive or the negative) then you MUST NOT use a fuse or breaker on the "grounded conductor" which is the fancy way of saying the grounded leg. Again, you can ground either the positive or the negative but it is much more common to ground the negative line and some DC electronics assume that the negative is grounded and are designed around that assumption. One common mistake that many people do when installing DC systems is that they think that the wiring practices from the automotive industry apply to household DC systems. If unless the negative is not grounded, it is illegal to use a black wire for the negative. This is because the negative is a grounded conductor so the code sees it as the same as the neutral on a normal 120/240 system. A grounded conductor must be white. Also, unless the positive is grounded, it is illegal to use a white wire for the positive.

The difference is that ~30V is the threshold where below that there is virtually no shock hazard and even 50V has very little shock hazard. Notice, shock hazard is very different from arc, short, and fire hazards. So as long as the battery voltage stays below 30V you don't have to worry about making your connections "touch safe" but you do need to make them so that they wont short out. Here is an interesting thread on shock danger. — electronics.stackexchange.com/questions/19103/how-much-voltage-is-dangerous

I don't know where a lot of these codes are or what the specific verbiage is but I studied solar, off grid solar (battery based), and advanced NEC compliance at SEI (Solar Energy International). I am now a "NABCEP Certified PV Installation Professional". I love these kinds of projects so keep me posted!

I hope this helps,

Maxfield Solar


How do I get my recessed light fixture flush? I installed two new recessed LED light fixtures using 4" new construction IC housings. The problem is that both fixtures are not flush against the ceiling after installation, they are dipping down on one side 1/4" or so.

Am I doing something wrong? Is my 1990's(Minnesota, USA) ceiling drywall too thick or something? Do I need a different fixture? I'll rig something up with tape/glue/etc. if necessary but I like the fixtures so don't want to return them. How can I get these fixtures flush with the ceiling?

I've tried removing the fixtures and reinstalling with the same results. The housings are as close to the drywall as possible and secured under and to the sides of the ceiling joists. The housing itself does slide into the hole in the drywall about 1/4" I would guess but does not completely go into the room; I'm not sure if this is typical or not.

The mechanism to secure the fixtures into the housing seems somewhat unique to me. It has clips that use friction to install, but will collapse if you turn the fixture clockwise to uninstall. It is best explained via an image:

Notes

Fixture: Commercial Electric 4 in. Recessed Soft White LED Can Disk Light Link 1 Link 2
Box: Halo T24 New Construction 4 in. LED Recessed Housing Link 1

The symptom of the gap you have in all my experience with recess lights have been the rough in housing has room for deflection. As you push the trim in place, the rough in pushes up also under the tension of the lens going in and it stays pushed up until the lens bottoms out on the ceiling and is released. The housing relaxes back down and creates the gap.

I have had some success minimizing the gap by twisting the trim slightly after the trim is meeting the ceiling. Twist it in the direction that keeps the tension fingers out on the lens. The wrong direction may allow the tension fingers to collapse for removal and you are back to square one.

If that does not work to your satisfaction, I have glued the rough in down to the drywall so it is stable enough to not rise when inserting the trim.

Blue tape the finished drywall to keep it clear of the adhesive you choose to use, it can be practically anything. Construction adhesive or painters caulk would be my choice. Push up on the rough in to expose the gap if possible of the upper drywall surface and rough in lip. Inject a lot of the tube in the space, it will be messy, have paper on the floor. Let the rough in back down, more may ooze out, keep it clean remove tape and let dry for a while. A day or two will work, longer the better, then try to reinstall.