MCC Side Entry

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Natfuelbilll

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A MCC has two adjescent empty bucket spaces. One is at end of MCC. The second is next to it. Above this second space is a 400A feeder breaker.

Do you know if UL would permit conduit entry through the side of the MCC with feeder cable running through the two empty spaces and terminating onto the 400A breaker?
 
My opinion is that as long as you meet the requirements of Art 312, especially 312.6, there is no problem.
 
Natfuelbilll said:
A MCC has two adjescent empty bucket spaces. One is at end of MCC. The second is next to it. Above this second space is a 400A feeder breaker.

Do you know if UL would permit conduit entry through the side of the MCC with feeder cable running through the two empty spaces and terminating onto the 400A breaker?
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I don't think UL would care one bit. They only care about how the thing was configured when it left the factory.

As for whether it meets code, my opinion is that as long as the instructions that come with the MCC do not prohibit it, you can enter the MCC structure with conduit wherever you want.

As someone else mentioned there are some cable deflection issues to meet.

I don't get why you would want to waste two expensive MCC buckets as a wiring channel, but I don't think it is forbidden. I would be more inclined to come in at the very bottom on the side and than up the vertical wiring channel so the two empty buckets could be used later on.
 
petersonra said:
I don't think UL would care one bit. They only care about how the thing was configured when it left the factory.

As for whether it meets code, my opinion is that as long as the instructions that come with the MCC do not prohibit it, you can enter the MCC structure with conduit wherever you want.

As someone else mentioned there are some cable deflection issues to meet.

I don't get why you would want to waste two expensive MCC buckets as a wiring channel, but I don't think it is forbidden. I would be more inclined to come in at the very bottom on the side and than up the vertical wiring channel so the two empty buckets could be used later on.
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I agree. Someone planned for and paid to have extra spaces for future additions to that MCC, you are ruining that prospect. MCCs are built with wireways for that purpose.
 
The specifier (not me) smoked crack. Above this 400A breaker is a 36 circuit panelboard. The single wireway is narrow. The same MCC has two full sections without any use.

This same engineer specified two entire MCC sections each with 18 circuit panelboards.

Your tax dollars at work.
 
I had a contractor enter the side of an MCC. My drawings showed that end was slatted for expansion on the next project. He had to eat the redo.

Personally, top or bottom - ONLY!

Oh, and I NEVER put pnlbds in an MCC. Expensive and hard to add circuits, wire initially, etc.
 
Natfuelbilll said:
A MCC has two adjescent empty bucket spaces. One is at end of MCC. The second is next to it. Above this second space is a 400A feeder breaker.

Do you know if UL would permit conduit entry through the side of the MCC with feeder cable running through the two empty spaces and terminating onto the 400A breaker?
Click to expand...


I have done this recently. Ordered a new section to an old switchboard and relocated the old feed, (Entire feed to this switchboard) from originating underground to this new entry into the new section, which would go horizontal back to the original termination point. It was approved in Texas ( San Antonio). I never thought about UL. It would appear once you get into the cabinets, it's a space issue but I could be wrong. There could be more to this.

The manufacturer knew what I was trying to accomplish (Square D) because I gave them the S.O. number from the original switchboard. They asked me what I was doing before they would quote the new cabinet.

I think the manufacturer would be able to give the information you desire...
 
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