Air Handler Question

[Tav1980]

Hello!

I have a question about sizing conductors and a breaker for an air handler. Attached is the name plate is below for reference. I just need a sanity check.

I plan on running NMC for the circuit, and it looks like that I will have to run #4 AWG. After I explain my reasoning, please let me know if I am off base, because I would rather run #6, but it doesn't look like that is an option.

Heater kit model being used is HKTS10X1 (see nameplate). Input voltage is 240V. The MCA is 49.1.55.6, and I am using the 55.6 MCA to size my conductor because the input voltage is 240. Since we must use the 60 degree column in 310.16 to size NMC conductors #6 is rated at 55 amps. Since the MCA is 55.6 amps I must go up to a #4 AWG if we stick with NMC, and the breaker would be 60 amps.

If I am in left field somewhere, please let me know. Thank you in advance!

 

[infinity]

I am using the 55.6 MCA to size my conductor because the input voltage is 240. Since we must use the 60 degree column in 310.16 to size NMC conductors #6 is rated at 55 amps. Since the MCA is 55.6 amps I must go up to a #4 AWG if we stick with NMC, and the breaker would be 60 amps.

You're correct. I might be tempted to use another wiring method at 75° C and with #6 copper conductors or #4 aluminum SE cable.

 

[Jraef]

You're correct. I might be tempted to use another wiring method at 75° C and with #6 copper conductors or #4 aluminum SE cable.

That was my thought too.

 

[augie47]

One word of caution: If you do decide to use AL, check the unit for termination data. Some require Cu conductors and you would need to switch over.