My handyman thinks I'm crazy for running 8 gauge THHN from my breaker to my spa pack, which pulls about 30-32 amps (1.5 hp motor and 5.5 kW heater). The spa pack and subpanel is 28 feet from my main panel, and I'm planning to use a 40 amp GFCI on that circuit. Nothing else but the spa pack on the circuit.
Am I in fact crazy? All the ampacity charts I'm seeing indicate that 8 gauge THHN (Cu) is good for 40-55 amps. He wants to use 6 gauge NM-B, and his argument is that the 8 gauge will run too hot, and potentially cook something if when/if the motor or the heating element go berzerk. But wouldn't the breaker trip in that case?
His concern doesn't make sense to me, but he's been doing this a lot longer than me, so I'm looking for a tie breaker. Thanks in advance for any thoughts or suggestions.
