Hello all, I have an existing Infared electric heater installed, nameplate amps is 25, OCP 30 amps, fed with #8 THWN in 3/4" flex. I am adding another heater right next to this one and I just wanted to make sure that I can share the #8 EGC I pulled the first time, I will just be adding the two ungrounded conductors to feed the second unit in the same raceway. I looked in 250.122 and for 30 ocp the min EGC is #10, and for 60 amp, which would be the total amps drawn by both units the EGC is still #10 so my #8 should be fine, right? Thanks
The EGC should be sized dependant upon the breaker that it needs to trip. For the 30 amp, #10 is typically fine, however, you increased the size of the ungrounded conductors (for voltage drop?), and therefore the EGC must be increased in proportion, requiring a #8 EGC. It sounds to me like your EGC size will be fine.