I want to know the answer to the following question:
What motivates an external drum brake held open electrically?
All the background I'm provided with is that "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 that enough to answer the question?
Answer: no