Two separate power sources sharing same raceway

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Bighand

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I was taught as a cub that two separate power sources couldn't share the same raceway. I have tried to find this in the code and cannot. What I found here in our factory is two MCC's located near each other have conduits coming from each of them and join together and power feed circuits from MCC's are joined into a common pipe and travel together and separating when getting to their own separate multiple motor control cabinets. They are 480 three phase and are sized to the same ampacities. My problem is the possibility that at least on set of wires of the same phase shorting together and back feeding ether MCC section when doing maintenance. I could throw the main on one MCC section and still have at least one leg still energizing multiple areas with in the MCC on the load side.

Can anyone help me locate support in the Code Book?
 
Re: Two separate power sources sharing same raceway

I don't think you are going to find it.

Remember, we can install a 120 volt and 277 volt circuit in the same raceway. The situation you describe is no different.
 
Re: Two separate power sources sharing same raceway

Originally posted by Bighand: I was taught as a cub that two separate power sources couldn't share the same raceway.
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Perhaps what you should have been taught instead that there are times when two separate power sources shouldn't share the same raceway. But that is a design choice, not a code issue.
 
Re: Two separate power sources sharing same raceway

There is one significant code requirement that does require separation in 517.30(C)(1). But it doesn't sound like that would apply in this situation.
 
Re: Two separate power sources sharing same raceway

Thanks for the help; I guess I was Wrong about the code. I'm going to have this design choice changed. I feel that the odds that we will have a back feed issue are slim and if the Electrical Techs here fallow all the proper procedures, no will be at risk. That still isn?t good enough for me or the rest of my coworkers. Thanks again for all of your help.
 
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