# Motor disconnect in control wiring



## MaxPower (Jun 10, 2012)

So I'm having a little disagreement with my supervisor at work and I'm hoping some of you can help me out. 

In a heat exchanger building, there are two exhaust fans being installed. They are both 3 phase 480 volt motors using 24 volt controls. The original blueprints had no disconnects whatsoever but are now being added. My boss claims that we can wire a disconnect in series with the hand auto switch in the control circuit. I'm disagreeing because I believe that the disconnect should be located in the power circuit but I can't find any specific code rules in the CEC that directly state that. The reason I think this is because I have seen contacts in the power circuit fused together, so I think having a disconnect in series between the contactor and the motor would be the proper location for the disconnect. 

If anyone has any information or knowledge that can help it would be greatly appreciated. Even if it proves me wrong.


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## KDC (Oct 19, 2012)

Disconnects for motors are laid out pretty clear in Section 28 of the CEC.

28-600 states that you need a disconnect for each motor branch curcuit, each motor starter or controller and each motor. One disconnect can serve as all of those, but that's subject to the location rules. 

Having it in the control circuit isn't going to meet code.


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## glen1971 (Oct 10, 2012)

Duplicate post...

Assuming that you have a 480 volt starter/breaker in an MCC or Distribution Panel, you don't need one beside the motor.. As I mentioned before, the On/Off, HOA, Start/Stop, etc is sufficient for starting and stopping the motor... Isolating it, by LOTO guidelines, you need to isolate the supply at the breaker..


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