<human>: Question: What motivates an external drum brake held open electrically?
Answer: there's at least 2 calipers on the disc), or 1 or more disc brakes with a single caliper at one end of the motor shaft or drive sheave which is used in machine room less elevators for compactness, breaking power, and redundancy(assuming there's 2 brakes or more).
 Is the question answered in a satisfactory fashion?

OPTIONS:
- yes
- no
<bot>: no