I'm installing a MrCool DIY multizone heat pump that can support up to 4 air handlers. The installation manual says use minimum 6 AWG, but the plate on the outside unit says 30 MCA with 45 MOCP. According to many sources, including the one here https://forums.mikeholt.com/threads/sizing-wire-and-circuit-breaker-for-air-conditioner.135804/ , I would be OK with 10 gauge based off the nameplate.
I understand that AC compressors are an exception to the normal NEC ampacity ratings, but I'm hoping someone might have insight into why the install manual would suggest something so out of line with what the plate implies.
Would I be OK with using 10 gauge NM-B from the panel in my basement to a disconnect on the outside of my house, and then a whip with 10 gauge to the compressor? It just doesn't feel right because there's such a big difference between 6 ga and 10 ga wire, so I'm wondering "what am I missing?"
I understand that AC compressors are an exception to the normal NEC ampacity ratings, but I'm hoping someone might have insight into why the install manual would suggest something so out of line with what the plate implies.
Would I be OK with using 10 gauge NM-B from the panel in my basement to a disconnect on the outside of my house, and then a whip with 10 gauge to the compressor? It just doesn't feel right because there's such a big difference between 6 ga and 10 ga wire, so I'm wondering "what am I missing?"
