Can a MCC directly feed a panelboard?

[muhasarr]

Can a MCC directly feed a panelboard if I wanted to utilize a spare bucket? Or would I have to install an transformer between the MCC and panelboard? What are the advantages and disadvantages of both design practices?

 

[petersonra]

Can a MCC directly feed a panelboard if I wanted to utilize a spare bucket? Or would I have to install an transformer between the MCC and panelboard? What are the advantages and disadvantages of both design practices?

mccs often have feeders for such things. I do not see any particular advantage or disadvantage.

I see no reason to add a transformer unless you need to change the voltage.

You can even buy panelboards and transformers inside the MCC.

 

[Ponchik]

I have not done any work with MCC, but why would it not work or be a violation? The bucket feeds another load center instead of a motor. Unless I am missing something.

 

[don_resqcapt19]

Just be careful as to the breaker type if you are tying to convert a spare starter bucket to a feeder. Many MCC starters have MCPs and not standard breakers. MCPs cannot be used as feeder breakers. They can only be used as part of a listed combination starter.

 

[Jraef]

Can a MCC directly feed a panelboard if I wanted to utilize a spare bucket? Or would I have to install an transformer between the MCC and panelboard? What are the advantages and disadvantages of both design practices?

As the others have said, sure you can, but it depends. For example if you have a 480V MCC and you want to feed a 480V DELTA breaker panel, no problem at all. If you want to feed a 480/277V 4 wire panel, you must have a neutral connection at the MCC, and that may not exist. A lot of 480V MCCs are used only for motors so there is no neutral bus, maybe not even a neutral landing lug in the MCC, because it was never going to be used.

In many 480V 3 wire MCCs, they will have "lighting panels" that are 120/240V 1 phase or 208Y120V 3 phase, so you WOULD need some sort of transformer for those, and the feeder breaker for the PRIMARY side of the transformer is coming off of the MCC bus.