LeftieBiker wrote: ↑Wed Aug 07, 2019 8:30 pm
webeleafowners wrote: ↑Wed Aug 07, 2019 5:15 pm
LeftieBiker wrote: ↑Wed Aug 07, 2019 3:58 pm
40 amp, actually, but 50 is a more common breaker size.
How does one do the math. I was just going with 27.5 amps x 240volts = 6.6KW
You are just doing the wrong math. 120% of the circuit rating is required for continuous loads like an EVSE. 27.5 amps x 1.2 = 33 amps. The next size breaker up is 40 amps.
Almost correct. Continuous calculated load is 80% of breaker or 1.25x load. 35 amp breakers while not as readily used are readily available.
https://www.lowes.com/search?searchTerm=35+amp+breaker
But breakers are sized used to protect wiring. If I had 10 AWG THWN handy I would have no issue wiring a EVSE that draws 27.5 amps protected with a 35 amp breaker. A 35 amp breaker can handle 28 amps continuous and 10 AWG THHN can handle 35 amps.
So what I did at my barn with a 60 amp sub panel. I used what I had handy. I had 8 AWG THHN, a 40 amp breaker and a 14-50R to Power my Nissan OEM EVSE. With 8AWG THHN I could have even used a 50 amp breaker if I had one handy. But I didn’t need the extra capacity for the EVSE.
