Cable feeding MCC

[adamscb]

Hi all,

Is there an ampacity requirement for a cable feeding an MCC (or any other kind of panel where the current capacity is known)? i.e. does it have to be rated for at least the current rating of the panel, or is there some multiplier? Where can this be found in the code?

Thanks

 

[petersonra]

Hi all,

Is there an ampacity requirement for a cable feeding an MCC (or any other kind of panel where the current capacity is known)? i.e. does it have to be rated for at least the current rating of the panel, or is there some multiplier? Where can this be found in the code?

Thanks

The feeder has to be protected properly like any circuit.

The size of the feeder would be calculated according to the motor feeder sizing requirements found in article 430. There are some maximum OCPD requirements found there as well if you choose to use the minimum ampacity allowed for the feeder.

There is no requirement to run a feeder to an MCC that is rated at the full rating of the MCC if that is what you are asking. For example, you could run a 200 amp feeder to an MCC that has a 600 amp main if the feeder calculations in article 430 allowed it. There may be good reasons to run a feeder sized to handle the maximum size of the MCC, but the code would not require it.

 

[augie47]

Agree with Bob. This is covered by Part II and Part V of Section 430