wire gauge? in middle of installing HPWC

[dethman]

so i'm installing my HPWC right now. my home was prewired for a car charger in he garage through my builder. looks like it's on a 50A breaker. my question is what gauge wire gauge is this, can it handle more than a 50A circuit, maybe 60A? thanks to any electricians in the house.

 

[MyJoule]

You should be able to see the marking on the wire- look at the other end in the circuit breaker panel. there should be plenty of it showing there. That would tell you for sure what gauge wire it is. I suspect the builder put in 8AWG for 50 amps (40 amp max draw) but you should be certain before you use it but if he used NM-B ( Romex style) then it probably is only rated at 40 amps ( 32 max draw)

 

[P85_DA]

looks like #8 cant handle more than u have

 

[dethman]

Bummer hoping it was 6awg. Will check the panel.

 

[P85_DA]

Check on wire it should be written down I’m just basing this on how it looks in pic

 

[gilscales]

most likely it is 8/3 nm-b romex and should be on a 40amp breaker but it could be 6/3 nm-b in which case you could put it on a 60amp breaker even though 55 amps is max rating, code says you can use a 60amp breaker, as others have said look for the markings on the wire if you can see enough of the jacket to find some printing, if you can't see it at that end then you could look at the main panel as there is probably enough wire in there that you would be able to spot the section with the printed size label

 

[schlammbad]

My guess is that is 6 gauge. Maximum current will depend on the rating of the cable you have. Assuming your cable is 6 gauge type NM-B, the current rating is 55A. That's the national standard. Some local jurisdictions may have different requirements or allowable currents. I have heard of some inspectors approving 50A circuits on 8 gauge, which seems strange to me. Since this circuit would see a continuous high current load from the car, I don't think I would want to push it if it were my house. "Continuous" in the code means" three hours or more." A 50A circuit is rated for about 40-42A continuous. The breaker is already the right size and I wouldn't set the car to charge higher than 42A. (Full disclosure: I'm not an electrician.)

 

[MP3Mike]

It looks like one of the strands of your black wire was nicked when they stripped it which will create a hot spot under load. It should be cut and re-stripped. (I'm sure most people don't pay any attention to nicks...)

 

[dethman]

checked out the panel. i'm actually guessing it may be 6awg. there is no label on the wire but it is sitting next to labeled 8awg wire and it is thicker than that.

here is my panel, car charger is on the 50A breaker near bottom right that is shut off with attached pink and black wires, go into black sheath. there is red and white 8awg labeled wire next to it (vertical), feels much thinner.

 

[juliusa]

I'd be sure before changing a breaker, and suggest leaving it at 50a anyway. Do you think you need the extra charging rate?

 

[dethman]

I'd be sure before changing a breaker, and suggest leaving it at 50a anyway. Do you think you need the extra charging rate?

yeah i'm just leaving it as a 50A circuit for now. installed and light is green, need a car to charge though. i'll have an electrician look at it another time.

 

[P85_DA]

@dethman what part of Socal u in ?

 

[dethman]

@dethman what part of Socal u in ?

irvine, in oc.

 

[P85_DA]

Lol plenty of Tesla’s in that area if u needed someone to test for u

 

[dethman]

Lol plenty of Tesla’s in that area if u needed someone to test for u

yeah pretty much teslatown over here. way too many.

 

[gilscales]

FYI, if you do find you have a 6/3 nm-b romex wire on that 50A breaker and you do change it to a 60A breaker then because of the 55 amp rating of the wire you should limit your charge rate to 44 amps (80% of max rating) anyway, you can charge at 40 amps now so you really won't notice much difference in that anyway, not sure its worth the trouble, I would most definitely make sure you have 6 gauge wire before charging past 32 amps though.