Breaker tripping

[JoelCool]

Electrician installed charger on 50 amp breaker. Guess he's installed many Tesla chargers. I believe it's 8 gauge wire like Thhxxx in 1/2 metal conduit like 10 feet long. Charger is commissioned for 50 amp breaker but when it comes up on my android Tesla app it starts at 48 amps. Of course it was tripping right away. Tried 40, then 30, then finally it was charging through at 20 amps for 19 mph :-(. Assuming something is wrong. Could it be the wiring size? Certainly not an electrician but watching vids makes it seem like it should be 6/3 wiring instead of 8?

Thoughts?

 

[yerEVan]

2 things come to mind. I would have used 6/2 plus ground in conduit. And when my breaker tripped it was because I didn’t have the connections on both charger and panel, torqued properly. Caused some serious scary issues.

 

[JoelCool]

I'm with ya. I've seen many videos on this. I'd assume the electrician understands all that. He indicated there are different levels of wire like a higher quality of 8 guage especially over such a short distance. Seems like 6/3 or 6/2 would have been better and if I have to replace it I will. I guess I can buy a torque wrench and double check all the connections. You pay for this *sugar* to be done properly. So bummed.....

 

[jjrandorin]

Electrician installed

Thoughts?

Call the electrician back out because its tripping and you paid for the install?

 

[240vPlug]

Yes #6 should be used IMO. Also if it's starting at 48 amps was not commissioned properly. It will only output 48 amps if it's commissioned for a 60amp breaker. Why a 50 amp breaker?

Unless you don't have capacity it should be installed on a 60 amp breaker, hard wired, with #6 (preferably THHN 90C in conduit).

 

[Sophias_dad]

The HPWC isn't commissioned properly. It shouldn't even be trying 48 amps. That said, it should be able to run at 48 amps for at least a little while(minutes) before the circuit breaker trips. You should not and can not rely on the car/app setting to keep the rate lower than 48 amps.

There is still a problem at the breaker. Either the breaker itself is defective or the connections are bad. Connection(s) because there's the obvious ones you screw in very tightly and the less obvious ones that clip onto the bus bars. When panels get old, their bus bars can get corroded and bad connections cause heat. Heat is one of the criteria that the breaker uses to trip.

 

[qdeathstar]

Electrician installed charger on 50 amp breaker. Guess he's installed many Tesla chargers. I believe it's 8 gauge wire like Thhxxx in 1/2 metal conduit like 10 feet long. Charger is commissioned for 50 amp breaker but when it comes up on my android Tesla app it starts at 48 amps. Of course it was tripping right away. Tried 40, then 30, then finally it was charging through at 20 amps for 19 mph :-(. Assuming something is wrong. Could it be the wiring size? Certainly not an electrician but watching vids makes it seem like it should be 6/3 wiring instead of 8?

Thoughts?

There us something wrong. 8 gauge wire shouldn’t be installed in 1/2 emt. The evse isn’t commissioned for a 50 amp breaker, it is commissioned for a 60 amp breaker. You would need #6 thhn not 6/2 romex.

Once the breaker got heat soaked it was more likely yo trip. If you don’t use it for an hr and give it time to cool off You should be able to charge at 40 amps unless the electrician didn’t properly tighten the lugs in the breaker or your panels buss bar is damaged.

 

[Cosmacelf]

There us something wrong. 8 gauge wire shouldn’t be installed in 1/2 emt. The evse isn’t commissioned for a 50 amp breaker, it is commissioned for a 60 amp breaker. You would need #6 thhn not 6/2 romex.

Once the breaker got heat soaked it was more likely yo trip. If you don’t use it for an hr and give it time to cool off You should be able to charge at 40 amps unless the electrician didn’t properly tighten the lugs in the breaker or your panels buss bar is damaged.

You are allowed three 8 gauge THHN in 1/2” EMT, so there is nothing wrong with the choice of conduit if he used 8 gauge,

Echoing others who said the problem is that EVSE didn’t get commissioned properly. It needs to be commissioned via an app to set it to a 50A breaker installation.

Also echoing others who said the electrician probably screwed up by not using 6 gauge and a 60A breaker to maximize your charging speed.

 

[mongo]

Also echoing others who said the electrician probably screwed up by not using 6 gauge and a 60A breaker to maximize your charging speed.

Seems harsh, install depends on panel/ service utilization. Unless they did a 14-50/ MC brain fart copy/paste.

 

[Cosmacelf]

Seems harsh, install depends on panel/ service utilization. Unless they did a 14-50/ MC brain fart copy/paste.

That seems to be what is happening a lot. Electricians are just assuming now that all EVSEs are 50A breakers. Just like they assume that NM-B 6 gauge works for 60A.

 

[ATPMSD]

Just like they assume that NM-B 6 gauge works for 60A.

This is a point not to be missed, #6 NM-B is NOT acceptable for use in a 60-amp EVSE circuit, you need #6 THWN (THNN would be better).

 

[mongo]

That seems to be what is happening a lot. Electricians are just assuming now that all EVSEs are 50A breakers. Just like they assume that NM-B 6 gauge works for 60A.

The 50A circuit is likely what they have the supplies on hand for. You want 60A? 50% (or more) price increase.

 

[qdeathstar]

You are allowed three 8 gauge THHN in 1/2” EMT, so there is nothing wrong with the choice of conduit if he used 8 gauge,

Shouldn’t and can’t are two different things.

 

[mongo]

Shouldn’t and can’t are two different things.

35% fill, 2.9 jam ratio but only a 10 foot run (guessing 180 degrees or less of bend). What's the shouldn't?

 

[qdeathstar]

35% fill, 2.9 jam ratio but only a 10 foot run (guessing 180 degrees or less of bend). What's the shouldn't?

I’ll just tell you a professional electrician would not do this and leave it at that. Not to mention that the connections to the wall charger isnt 1/2” so I can guess what that connection looks like….

 

[JoelCool]

Thanks everyone for the excellent feedback. I do have the electrician coming back out so I'll see what he says. He will double check all screws for tightness and bring a spare breaker. I went back through commissioning and it was/is set for 50 amp breaker so that part is good. I will set the phone app to 40 now and see what happens. I did see thhn on the wires in the panel but not sure if it's 8 or 6 but pretty sure it's 8. The conduit has 3 90 degree bends. Hopefully I'll post what fixes the issue.

 

[Sophias_dad]

Thanks everyone for the excellent feedback. I do have the electrician coming back out so I'll see what he says. He will double check all screws for tightness and bring a spare breaker. I went back through commissioning and it was/is set for 50 amp breaker so that part is good. I will set the phone app to 40 now and see what happens. I did see thhn on the wires in the panel but not sure if it's 8 or 6 but pretty sure it's 8. The conduit has 3 90 degree bends. Hopefully I'll post what fixes the issue.

If the HPWC was commissioned for a 50 amp breaker and the car was saying it could take 48 amps, the HPWC or car is defective.

 

[ATPMSD]

If the HPWC was commissioned for a 50 amp breaker and the car was saying it could take 48 amps, the HPWC or car is defective.

Or the app. Check this is the car, if it is really drawing 48 amps you should see something like 48/48 on the dash. It will start as 0/48 then increase until the breaker trips.

 

[jeremymc7]

Correct me but if this is set for 50A he shouldn’t be able to get more than 40A out of it, reliability anyway, assuming everything is up to snuff.

 

[Jerryr]

3 #8 AWG THHN/THWN conductors is fine for 50 amps with a 10 ft run in 1/2 metal conduit , 8/3 NM-B or UF is only good for 40 Amps.

Two things don't sound right:

1- The Wall connector should never have ramped up to 48 amps if it properly accepted being commissioned for 50 Amps service.
2- The breaker should not have tripped if car was set for 40 amps or below. Possible bad breaker or loose connection.

The electrician will figure it out.