220 Volt, Single Phase Wire Size Help Needed

[workinonit]

Typically 2 trade sizes lower for a ground. Heat strips can run from 5 KW to 40 KW and some maybe larger but normally residential strips are 10 or 20 KW. That determines the wire size.

 

[MAX-24-Dean]

I was looking at a home and the heat pump.
The air handler has a resistance backup heating element in it.
The backup heat is fed by two large wires, like maybe #6,, it is stranded and at least three times the size of #10 wire.

My question is about the ground, the two wires feeding 220 volts into the air handler are large,,
but, the ground wire is only #10.

I am only used to house wiring, like outlets, and lighting circuits, where all of the wires are the same diameter.

Does a 60 amp, 220 volt, single phase circuit only need a #10 ground?? Or did someone "cheap out"??

Equipment Grounding Conductor (EGC) size is determined by Table 250-122 in the 2020 National Electric Code.
From the table, the EGC size is determined by the Rating of the Over Current Protection Device (OCPD = breaker) in the table. A 60 Amp breaker in the table requires a minimum size of a #10 EGC.