Minimum MCC bus rating?

[PCEC]

I' have a job where I have a few small motors to go in an MCC. The total connected load will be 67A @600v, is there such a thing as a 200A rated MCC? I can't find info indicating such a thing exists.

 

[petersonra]

I doubt it. You might find one though if you look hard enough.

There is not a lot of difference in cost between different bus sizes so MCC manufacturers have standardized a just a few.

What difference does it make anyway, as long as the bus is big enough.

if it is about cost you can probably have a motor control panel fabricated by a UL508a shop for half or a third of what an MCC costs.

 

[Jraef]

I don't know of anyone offering less than 600A main bus. As Bob said, there would be very little difference in cost anyway, but the other issue would be that the minimum vertical bus will be 300A, so a 200A main bus would be pointless.

If you need the convenience of an MCC in terms of removing buckets or isolating only one unit (because in a control panel, that's more difficult in light of the new Arc Flash issues), just get whatever is standard. But if the nature of your machine/process is such that if any one thing is off, they might as well all be off, then go with a control panel. You can get bus bar systems for use in control panels that allow you to unplug individual IEC style starters, any decent panel builder can do that for you and likely cost less than an MCC.

 

[PCEC]

That was what I thought. Thanks.