air conditioner branch circut

[elec-student]

what is the single air conditioners full load amps can be served from a branch circut with conductors having an ampacity of 40 amps? i looked in 440-62 in the 2002 code book and it just give the ac req. 40 at 250 volts

 

[bphgravity]

Re: air conditioner branch circut

460.62 covers provisions for room air conditioners like window units. Your question doesn't imply this is the case. Go back to 440.32. If you already know that the branch-circuit conductors are 40-amp, than the full-load current of the A/C unit cannot be more than 32 amps or 25% below the OCD of the circuit. (32-amp times 125% = 40-amp)

 

[bob]

Re: air conditioner branch circut

Look at 440.62B. If you have installed a circuit that has a capacity of 40 amps, then you must have applied 440.62B. 40 amps x 0.80 = 32 amps.
This comes from the requirement that continuous
loads must apply a 1.25 factor the the actual full load currrent. 1.25 x 32 = 40 amps.
440.62C requires that the AC unit load not exceed 50% of the circuit capacity where there are other loads connected.

[ March 19, 2003, 12:35 PM: Message edited by: bob ]