Load calcs with Condensing units and Rooftop units

[steve66]

I'm totally confused: If I do a load calc. for a service, and I have several condensing units or rooftop HVAC units, do I need to use the MCA from each unit? Or can I just use the MCA from the largest unit, and the full load amps from all the smaller units?

I don't see anything specific in 220, so I looked at article 440 which refers to 422 and 430 and that's about where I get lost.

There is no electric heat in these units - just motors and compressors.

 

[Smart $]

If the units have an MCA, that's what you use. Code makes no concessions for multiple units already having 125% figured into the MCA values. If you do want to make concessions for such, I'd run it by the AHJ beforehand for approval... :happyyes: