I used to think this question would be a simple question, but I haven't been able to get a good explanation from anyone (including two electrical engineers). So, here goes During a brownout (periods where a building does not receive it's normal level of voltage) motors can potentially overheat to the point of failure. As I have been lead to understand, it is because motors are designed to operate at a certain HP (745 watts). So, when the voltage drops, the current will have to increase in order to maintain this HP. However, the windings of the motor may not be able to handle this current, and the excessive heat can pose a real danger to the integrity of the motor. The part I can't understand is - what component on the motor is drawing this extra current. It's my understanding that a motor is a dumb piece of equipment that operates at a given HP when it's on. I just don't understand what part of the motor is drawing this additional current, and how it knows to draw this additional current.