60A Breaker Trips in Daytime Vegas Heat Only

[DownshiftDre]

Desert Installation from April 2022. No problems since this past month but I rarely charge in the daytime as 99% charging happens before 7:30am departure. Electrical panel is on exterior and the Wall Connector is same wall but interior. 3ft distance max wiring maybe?

This month I have had to charge my car in the middle of day few times due to lots of air travel and the breaker will suddenly trip after about 45mins when set to normal 48amps. If I set to 45amps it seems I can charge for extended time.

I checked panel for anything major (char) and did not like the ground neutral installation I saw so I called another electrician out. Prior to that I called Tesla and they didnt see anything wrong with wall charger itself through charger diagnostics as it was charging on phone and even when the breaker tripped while on phone with Tesla.

New electrician said through visual only:
-Wiring is 6awg and should be 4awg. Reminder distance between panel and Wall Connector is minimal.
-Use metal conduit instead of the current plastic conduit inside the garage
-Neutral/ground install is bad. Has cut many main strands out to make it fit instead of using different bigger lug and the wire wraps behind busbars.
-Change the Eaton BR260 breaker with new (he didnt check underside to see if any issue)
-He did mention we can just change down to a 50A breaker and then I just commision charger to a lower charge rate for a 50A breaker.

Do you think the wiring size is the main reason why it trips during the day? I was initially thinking my panel is getting hot due to summer daytime heat, and that I am getting into a marginal derate condition for the breaker rating and therefore tripping right at or below the 80% of the 60A breaker.

Arent breakers calibrated/rated at 40C (104F) and therefore anything higher causes a lower trip point? It is 104F and more already in Vegas daytime not to mention other two 35A HVAC breakers heating up panel and then add in heat from 48 amp wall charger. I could see a 50C condition easily happening within panel.

Quoted me $300 parts and labor since he is close friend to my brother in law. So its not like its a major cost issue here plus would like to have it done to correct gauge. Just want to make sure we are tackling the real problem and not beefing up something we dont need to if the weak point is the breaker in the summer daytime heat.

Thoughts appreciated. Thinking to have him out this weekend to install.

 

[mongo]

Desert Installation from April 2022. No problems since this past month but I rarely charge in the daytime as 99% charging happens before 7:30am departure. Electrical panel is on exterior and the Wall Connector is same wall but interior. 3ft distance max wiring maybe?

This month I have had to charge my car in the middle of day few times due to lots of air travel and the breaker will suddenly trip after about 45mins when set to normal 48amps. If I set to 45amps it seems I can charge for extended time.

I checked panel for anything major (char) and did not like the ground neutral installation I saw so I called another electrician out. Prior to that I called Tesla and they didnt see anything wrong with wall charger itself through charger diagnostics as it was charging on phone and even when the breaker tripped while on phone with Tesla.

New electrician said through visual only:
-Wiring is 6awg and should be 4awg. Reminder distance between panel and Wall Connector is minimal.
-Use metal conduit instead of the current plastic conduit inside the garage
-Neutral/ground install is bad. Has cut many main strands out to make it fit instead of using different bigger lug and the wire wraps behind busbars.
-Change the Eaton BR260 breaker with new (he didnt check underside to see if any issue)
-He did mention we can just change down to a 50A breaker and then I just commision charger to a lower charge rate for a 50A breaker.

Do you think the wiring size is the main reason why it trips during the day? I was initially thinking my panel is getting hot due to summer daytime heat, and that I am getting into a marginal derate condition for the breaker rating and therefore tripping right at or below the 80% of the 60A breaker.

Arent breakers calibrated/rated at 40C (104F) and therefore anything higher causes a lower trip point? It is 104F and more already in Vegas daytime not to mention other two 35A HVAC breakers heating up panel and then add in heat from 48 amp wall charger. I could see a 50C condition easily happening within panel.

Quoted me $300 parts and labor since he is close friend to my brother in law. So its not like its a major cost issue here plus would like to have it done to correct gauge. Just want to make sure we are tackling the real problem and not beefing up something we dont need to if the weak point is the breaker in the summer daytime heat.

Thoughts appreciated. Thinking to have him out this weekend to install.

Non-electrician thoughts:
Sounds like general heat issue. As you've already done, lowering the WC configuration or vehicle charge limit avoids the problem (assuming there isn't a bad connection in there).

Wire gauge depends on if it is individual THHN wires in conduit or NM-B (Romex) with its own outer wrapping.

Cut strands is not good. Neutral is not used by the Tesla Wall Connector, but ground is very important.

Conduit type might give marginally better cooling, but likely wouldn't impact the breaker issue.

 

[Sophias_dad]

4AWG would definitely produce less heat, but the 6AWG in conduit is allowed to carry 65 amps(52 continuously), so it SHOULD be okay. If some numbnuts put 6AWG NMB through conduit for a a short run, that wouldn't be okay at all. Not only is the NMB only allowed to carry 55(44 continuous), the PVC conduit would provide a LOT more insulation.

Using metal conduit would very likely help.

Neutral/ground install being bad is pretty irrelevant here. The neutral isn't even connected at the WC and the ground is connected but SHOULD be carrying no current. Not saying its a good install, just that it won't be causing your problems even if there was only ONE strand connected. I'm sort of surprised they are even using a stranded wire for ground(if they are), since it only has to be 10 gauge(with 6AWG conductors).

Changing the breaker to a 50 amp would be unnecessary if you tell the WC its a 50 amp breaker. Its actually almost better to leave the breaker as a 60 since there's more tolerance for heat that way.

 

[eskudo12791]

Neutral/ground install being bad is pretty irrelevant here.

Wonder if they are just calling it neutral when seeing white, since the white is likely being used for the second pole

 

[mongo]

Wonder if they are just calling it neutral when seeing white, since the white is likely being used for the second pole

Doubt it, second hot lead would go to the breaker which has properly sized terminals.

 

[DownshiftDre]

Wonder if they are just calling it neutral when seeing white, since the white is likely being used for the second pole

Yes currently 3rd wire is white and is stranded. It is on the left side of panel with a bunch of other whites (neutral?). The right side of panel is many bare wires. Should the wire be on the right side with the bare wires instead.

Electrician yesterday mentioned panel is modern and all my neutral bar are connected to ground anyways. House built in 2015. I dont know the relevance or context of that neutral/ground statement so Im probably using it interchangeably incorrectly.

 

[zoomer0056]

Desert Installation from April 2022. No problems since this past month but I rarely charge in the daytime as 99% charging happens before 7:30am departure. Electrical panel is on exterior and the Wall Connector is same wall but interior. 3ft distance max wiring maybe?

This month I have had to charge my car in the middle of day few times due to lots of air travel and the breaker will suddenly trip after about 45mins when set to normal 48amps. If I set to 45amps it seems I can charge for extended time.

I checked panel for anything major (char) and did not like the ground neutral installation I saw so I called another electrician out. Prior to that I called Tesla and they didnt see anything wrong with wall charger itself through charger diagnostics as it was charging on phone and even when the breaker tripped while on phone with Tesla.

New electrician said through visual only:
-Wiring is 6awg and should be 4awg. Reminder distance between panel and Wall Connector is minimal.
-Use metal conduit instead of the current plastic conduit inside the garage
-Neutral/ground install is bad. Has cut many main strands out to make it fit instead of using different bigger lug and the wire wraps behind busbars.
-Change the Eaton BR260 breaker with new (he didnt check underside to see if any issue)
-He did mention we can just change down to a 50A breaker and then I just commision charger to a lower charge rate for a 50A breaker.

Do you think the wiring size is the main reason why it trips during the day? I was initially thinking my panel is getting hot due to summer daytime heat, and that I am getting into a marginal derate condition for the breaker rating and therefore tripping right at or below the 80% of the 60A breaker.

Arent breakers calibrated/rated at 40C (104F) and therefore anything higher causes a lower trip point? It is 104F and more already in Vegas daytime not to mention other two 35A HVAC breakers heating up panel and then add in heat from 48 amp wall charger. I could see a 50C condition easily happening within panel.

Quoted me $300 parts and labor since he is close friend to my brother in law. So its not like its a major cost issue here plus would like to have it done to correct gauge. Just want to make sure we are tackling the real problem and not beefing up something we dont need to if the weak point is the breaker in the summer daytime heat.

Thoughts appreciated. Thinking to have him out this weekend to install.

Disclaimer: I'm not an electrician, nor do I play one in real life. I agree with the electrician. Another thing you can do is get a digital IR thermometer to check breaker while in use. Don't cheap out, get a good breaker. I don't know what a good one is. 6awg THHN wire is sufficient. Yes, use metal conduit.

 

[eskudo12791]

Doubt it, second hot lead would go to the breaker which has properly sized terminals.

Would have to see if its 6/2 or 6/3

 

[DownshiftDre]

4AWG would definitely produce less heat, but the 6AWG in conduit is allowed to carry 65 amps(52 continuously), so it SHOULD be okay. If some numbnuts put 6AWG NMB through conduit for a a short run, that wouldn't be okay at all. Not only is the NMB only allowed to carry 55(44 continuous), the PVC conduit would provide a LOT more insulation.

Using metal conduit would very likely help.

Neutral/ground install being bad is pretty irrelevant here. The neutral isn't even connected at the WC and the ground is connected but SHOULD be carrying no current. Not saying its a good install, just that it won't be causing your problems even if there was only ONE strand connected. I'm sort of surprised they are even using a stranded wire for ground(if they are), since it only has to be 10 gauge(with 6AWG conductors).

Changing the breaker to a 50 amp would be unnecessary if you tell the WC its a 50 amp breaker. Its actually almost better to leave the breaker as a 60 since there's more tolerance for heat that way.

Looking at the installation and learning more about it when the electrician was in yesterday, it is 6/3 NM-B because it had a black rubber cover to it. Has 3 wires and a bare ground. 4 wires total. It goes into plastic schedule 40 conduit in the garage where it comes out of wall to go down into the wall connecton where then the black rubber is opened up and connections made.

Electrician said he will be using different 4awg wire that are individual wires and not grouped in a bundle like the one I have.

 

[mongo]

Looking at the installation and learning more about it when the electrician was in yesterday, it is 6/3 NM-B because it had a black rubber cover to it. Has 3 wires and a bare ground. 4 wires total. It goes into plastic schedule 40 conduit in the garage where it comes out of wall to go down into the wall connecton where then the black rubber is opened up and connections made.

Electrician said he will be using different 4awg wire that are individual wires and not grouped in a bundle like the one I have.

Like thickish rubber? Is it round? Sounds like SOOW, not NM-B.

 

[DownshiftDre]

And really appreciate all the comments this morning. Was hoping to get barely a single basic response but ending up with many great responses and learned my wire type (NM-B).

 

[mongo]

Would have to see if its 6/2 or 6/3

Unless they are charging at 120V, white (redesignated with tape) from a 6/2 would still connect to the breaker.
6/3: black and red to breaker, white and bare ground to bus bar.
6/2: black and white to breaker, bare ground to bus bar.

 

[DownshiftDre]

Just researched SOOW vs NM-B. I think it is NM-B. The copper strands are thick, not thin and there is a bare uncolored 4th wire.

 

[mongo]

Just researched SOOW vs NM-B. I think it is NM-B. The copper strands are thick, not thin and there is a bare uncolored 4th wire.

Oh duh, yeah bare wire is NM-B.

 

[Cosmacelf]

Ugh. Why would anyone use NM-B inside a conduit? Was it because there isn’t a continuous conduit from the electrical box to the Wall Connector?

If your panel is a main panel, then grounds and neutrals will be bonded together , so it doesn’t matter that the third wire is connected to the “neutral” side. It is indeed used as a ground though.

The number one thing that will fix this though is replacing the breaker since it appears to be tripping due to environmental heat.

 

[cmaster]

Temperature will affect breakers since breakers work similar to how fuses work. When enough heat accumulates, it affects the mechanical properties of the breaker. At 60Amp, it is rated so that under ideal conditions, the 60Amp current induced temperature is able to sustain the energy.

Electricity and Temperature are related to Energy by the way.

"Generally, the temperature of a circuit breaker should not exceed 140oF. If it does, this means the circuit breaker is in danger of tripping. A good "rule of thumb" is that if you can't hold your finger on the plastic part of the circuit breaker without getting burned, it is too hot."

HEATING EFFECT OF AN ELECTRIC CURRENT

Elinikäinen ja toimintavarma kotimainen oppimisen ympäristö

peda.net

 

[DownshiftDre]

Ugh. Why would anyone use NM-B inside a conduit? Was it because there isn’t a continuous conduit from the electrical box to the Wall Connector?

If your panel is a main panel, then grounds and neutrals will be bonded together , so it doesn’t matter that the third wire is connected to the “neutral” side. It is indeed used as a ground though.

The number one thing that will fix this though is replacing the breaker since it appears to be tripping due to environmental heat.

The electrical panel and wall connector are pretty back to back to each other on same wall. Looks like routed through wall without conduit into garage and then plastic conduit starts in garage and down to Wall Connector.

I was initially thinking it was a breaker 40C derate given Vegas extreme temperatures.

I will likely go with this wire and breaker overhaul anyways to get things as robust as possible. If it still trips with a new breaker I will reduce amps to 45A in the 2 months of extreme summer and move on. At least I will have a setup that I know is safe and as best as can be. I rarely charge in daytime but things happen for a reason, and lets correct this now that it has the attention and better this than a fire.

 

[DownshiftDre]

Temperature will affect breakers since breakers work similar to how fuses work. When enough heat accumulates, it affects the mechanical properties of the breaker. At 60Amp, it is rated so that under ideal conditions, the 60Amp current induced temperature is able to sustain the energy.

Electricity and Temperature are related to Energy by the way.

"Generally, the temperature of a circuit breaker should not exceed 140oF. If it does, this means the circuit breaker is in danger of tripping. A good "rule of thumb" is that if you can't hold your finger on the plastic part of the circuit breaker without getting burned, it is too hot."

HEATING EFFECT OF AN ELECTRIC CURRENT

Elinikäinen ja toimintavarma kotimainen oppimisen ympäristö

peda.net

Yes see below Eaton recommendations for breaker derating. Calibrated at 40C. Current trip goes higher for colder temps. Current trip goes lower for hotter temps.

Temperature Derating of Eaton MCCBs ?

 

[davewill]

Ugh. Why would anyone use NM-B inside a conduit? Was it because there isn’t a continuous conduit from the electrical box to the Wall Connector?

If your panel is a main panel, then grounds and neutrals will be bonded together , so it doesn’t matter that the third wire is connected to the “neutral” side. It is indeed used as a ground though.

The number one thing that will fix this though is replacing the breaker since it appears to be tripping due to environmental heat.

Probably because he didn't want to cut the drywall to run it through the studs and didn't have THHN in the truck...or he's an idiot. Of course, those two choices are not mutually exclusive. If the new electrician is going to change it over to THHN, he could use 6AWG, but if he's willing to use 4AWG and wrestle it into the wall connector, that's great.

That said, I don't think the wire choice explains the tripping breaker. I have to think the OP either got a dud of breaker, or the connections at the breaker were not tight enough. Given the quality of the work, I'd wonder whether the guy just chucked some used breaker he happened to have in the truck in there.

 

[Rocky_H]

Wiring is 6awg and should be 4awg.

it is 6/3 NM-B because it had a black rubber cover to it.

The good news is that this is straightforward. Your previous electrician was a moron who violated electric code in a pretty basic way. There's nothing wrong with using NM-B, but it is necessary to use the right gauge of wire. 6 gauge NM-B simply does not meet the rating for a 60A circuit. Period. So this is correct, that if it's going to use NM-B, it should have been 4 gauge.

You can just change this to a 50A circuit, drawing 40A continuous, and it should be fine.