motor start capacitor smoking

[Electron_Sam78]

anyone know why a motor start capacitor would smoke and then leak liquid. After that the motor overload trips out. At first I thought capacitor just went out but it did it agin with the replacement cpacitor. Internal motor winding problem perhaps? It's a single phase, 5 HP, 240V

 

[kwired]

switch that opens the circuit to the capacitor after motor reaches a certain speed is not opening. Start capacitors are only intended to be in the circuit while starting.

or motor is not reaching enough speed to open the switch

 

[LarryFine]

Sounds like overheating. Does the motor freewheel easily? How well did it start with the new cap at first?

 

[Electron_Sam78]

I replaced the start capacitor along with the start relay and it works fine now. After I did that I noticed that the motors were short cycling, coming on every 30 seconds or so and running for a few seconds then shutting down. I imagine that was the original problem that caused the capacitor and possibly the start relay to go bad.

 

[mcclary's electrical]

I replaced the start capacitor along with the start relay and it works fine now. After I did that I noticed that the motors were short cycling, coming on every 30 seconds or so and running for a few seconds then shutting down. I imagine that was the original problem that caused the capacitor and possibly the start relay to go bad.

I used to have a "general list" rule of thumb for motors from 1-400 HP that listed the maximum number of starts per hour, and cool down time between them, and not suprisingly, most manufacturing processes far exceed the list. But anyway, I can't find it to even share. I think it's on my old laptop.