sizing a feeder for 9 heat pumps with supplimental electric heat

[mshields]

I've got 9 heat pumps each with electric heat and I'm in the process of sizing the feeder to panel that will serve them all.

The electric heat part is easy. This has to be taken at 100% I know. My question pertains to the remaining loads consisting of compressors and fans. My inclination is to take these at .7 demand factor. But my question is whether or not this is defined somewhere in the code. I don't see anything in 220 and Article 440 only gives direction on branch circuit feeders to individual AC units.

What governs this feeder size?

Thanks,

Mike

 

[david luchini]

Try 430.63 and 430.24

 

[kwired]

Are controls arranged so that the compressors and aux heat would never run simultaneously? If so you maybe able to disregard the lesser load - which is probably the comrpessors. Keep in mind some units do kick on at least some aux heat while in defrost mode.