I’ve got a 100 amp main breaker in my center fed panel, and I see that the bus bars are rated for 125 amps. I’d like to add a 50 amp circuit for EV charging, but my current load calculation is about 65 amps (all gas appliances).

I called my power company to ask if they would have to upgrade the service drop - I eyeball it to be 4 AWG - and if they would have to sign of on me upgrading the main breaker. They came out to look and gave me a hesitant answer of “no” to both questions.

Does that seem right? If it were 4 AWG copper coming in from overhead, I think the feeder has an ampacity rating of 100 amp. I read there’s a 83% service factor that applies, but even with that I don’t think the service drop would support 125 amps.

Picture of the panel sticker

I’ve got a 100 amp main breaker in my center fed panel, and I see that the bus bars are rated for 125 amps. I’d like to add a 50 amp circuit for EV charging, but my current load calculation is about 65 amps (all gas appliances).

I called my power company to ask if they would have to upgrade the service drop - I eyeball it to be 4 AWG - and if they would have to sign of on me upgrading the main breaker. They came out to look and gave me a hesitant answer of “no” to both questions.

Does that seem right? If it were 4 AWG copper coming in from overhead, I think the feeder has an ampacity rating of 100 amp. I read there’s a 83% service factor that applies, but even with that I don’t think the service drop would support 125 amps.

Picture of the panel sticker

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