Wall connector keeps tripping breaker

[PoitNarf]

Finally got my wall connector up and running on Saturday. It’s connected to a 240v 60 amp circuit. I tried charging at the full 48 amps but my breaker kept tripping. I managed to get a stable charge without tripping the breaker by setting my Model 3 to only draw 38 amps. If I even bump it up to 40 amps it will eventually trip the breaker after about 10 minutes of charging or so. I’ve confirmed that the dial setting inside the wall connector is currently at “9” which according to the install manual should be for when it’s connected to a 60 amp breaker and should allow for charging at up to 48 amps.

Anyone else experience something like this? I’m wondering if maybe the breaker is bad. The House was upgraded from 100 to 200 amp and I’ve got a whole new breaker panel with all new breakers. Luckily my electrician is coming back again later this week to finish up some other work so if it’s some issue with the breaker itself he should be able to resolve it.

 

[TonyWilliams]

Weak breakers are common. Throw that one away and get a new one. They're cheap.

 

[keydiver]

Cheap Chinese breaker. Rather common problem.

 

[Stu Redman]

What gauge wire is the circuit using and how long a run? It really may be getting hot.

 

[brkaus]

Is anything hot?

My first 50a breaker on my 14-50 circuit had a slight buzz and quickly overheated and tripped.

New breaker and no problems in 12 months.

 

[DarthPierce]

What gauge wire is the circuit using and how long a run? It really may be getting hot.

The breaker doesn't know if the wire is hot. It's just tripping at the wrong current.

 

[Stu Redman]

From The Spruce.com

"An overloaded circuit is the most common reason for a circuit breaker tripping. It occurs when a circuit is attempting to draw a greater electrical load than it is intended to carry. When too many appliances or light fixtures are operating at the same time, the circuit wires heat up. Sensing this, the circuit breaker mechanism trips, breaking the circuit and shutting off the flow of electricity."

 

[PoitNarf]

I haven't checked if anything is hot to the touch. I'll try it again after work. The wall connector is on a dedicated 60 amp circuit, nothing else is on that circuit. I'm leaning towards a bad breaker or loose connection in the breaker box as the most likely causes. Hoping my electrician can identify and fix the problem quickly.

 

[DarthPierce]

From The Spruce.com

"An overloaded circuit is the most common reason for a circuit breaker tripping. It occurs when a circuit is attempting to draw a greater electrical load than it is intended to carry. When too many appliances or light fixtures are operating at the same time, the circuit wires heat up. Sensing this, the circuit breaker mechanism trips, breaking the circuit and shutting off the flow of electricity."

If that was a response to my comment about a circuit breaker not knowing the temperature of the wiring - I stand by my statement. I'm an electrical engineer.

A circuit breaker is responding to the current flowing through the breaker. It has absolutely no knowledge of anything outside itself. It cannot magically measure the temperature of something elsewhere.

It's reason for existence is to prevent overheated wires but it does so by shutting off current flow when too much current is flowing; there is absolutely no means for it to detect the temperature of your house wiring. Electronics are not magic.

Edit to add: TheSpruce.com looks basically like pinterest.... that's not a real explanation of a circuit breaker.

 

[adamwglass]

Pretty smart guys on this thread.

 

[dhrivnak]

The breaker doesn't know if the wire is hot. It's just tripping at the wrong current.

Actually many are thermally tripped so yea heat, lose connection or too small of wire are all possibilities. But I agree with many likely a faulty breaker.

 

[GWord]

The breaker doesn't know if the wire is hot. It's just tripping at the wrong current.

Heat is the primary mechanism that causes a residential breaker to trip. That's why NEC requires a breaker derate in high temp installations. Copper and aluminum wire are good conductors of heat, they conduct it right into the breaker mechanism.

 

[ShawnA]

Hi PoitNarf,

The others are probably right about a weak breaker.... But
What is the actual voltage as indicated by your car?
Hopefully the 3 shows the voltage like the S and X.

There is an obscure DIP switch setting that changes position if your
voltage is 240 Volts or less... Shown on page 20 of the Wall Connector Install Manual...

Check to make sure it really is a 60A breaker.
Those weak numbers combined with old eyes can make mistakes.

Shawn

 

[PoitNarf]

Check to make sure it really is a 60A breaker

Ding ding ding! Electrician is here now finishing up the last bit of stuff he couldn’t get to on Saturday. After I told him about the charging issues I was having he then idenitified the problem. He worked a 12 hour day at my place on Saturday, did an upgrade of my house from 100 to 200 amp, new connections outside (weather head, conduit, meter, main disconnect), new breaker panel and all new breakers. Pretty big job. He ended up finally wiring the wall connector to the breaker panel near the end of that 12 hour day and accidentally put in a 30 amp breaker instead of 60 amp. I don’t blame him at all. Him and his team worked their asses off on Saturday. Luckily it was a simple fix and I’m all good now.

Had I known then that you don’t add the numbers together on a double pole breaker to get the total amps I would have figured that out immediately. Now I know, and knowing is half the battle

 

[ShawnA]

Yahoo! Relax... From the symptoms I thought it might have been a 40A or 50A.
I would not have guessed a 30A breaker.
Enjoy your new charging setup... They are really nice.

Shawn

 

[davewill]

Ding ding ding! Electrician is here now finishing up the last bit of stuff he couldn’t get to on Saturday. After I told him about the charging issues I was having he then idenitified the problem. He worked a 12 hour day at my place on Saturday, did an upgrade of my house from 100 to 200 amp, new connections outside (weather head, conduit, meter, main disconnect), new breaker panel and all new breakers. Pretty big job. He ended up finally wiring the wall connector to the breaker panel near the end of that 12 hour day and accidentally put in a 30 amp breaker instead of 60 amp. I don’t blame him at all. Him and his team worked their asses off on Saturday. Luckily it was a simple fix and I’m all good now.

Had I known then that you don’t add the numbers together on a double pole breaker to get the total amps I would have figured that out immediately. Now I know, and knowing is half the battle

I would sure blame him! What if he had muffed the install the other way, with a 100a breaker where the 60a should go? Would you be so forgiving after the fire a year down the road?

 

[DarthPierce]

Actually many are thermally tripped so yea heat, lose connection or too small of wire are all possibilities. But I agree with many likely a faulty breaker.

Heat is the primary mechanism that causes a residential breaker to trip. That's why NEC requires a breaker derate in high temp installations. Copper and aluminum wire are good conductors of heat, they conduct it right into the breaker mechanism.

Heat IN the breaker is caused by excess current and is a mechanism to cause tripping - heat in the wires in the house is NOT detectable by the breaker. That's exactly why you size the breaker according to the wiring and outlets it's connected to.

 

[GWord]

Heat IN the breaker is caused by excess current and is a mechanism to cause tripping - heat in the wires in the house is NOT detectable by the breaker. That's exactly why you size the breaker according to the wiring and outlets it's connected to.

Yes and no; a significant and fast temp rise won't have time conduct thermal energy into the breaker, like you say. A marginally undersized wire that doesn't experience catastrophic failure but operates beyond the spec of the breaker can cause nuisance trips via temperature conduction through the metal conductors of the wire and breaker internals.

 

[drawfour]

would sure blame him! What if he had muffed the install the other way, with a 100a breaker where the 60a should go? Would you be so forgiving after the fire a year down the road?

I agree! If the wiring can't handle the current and he put in the wrong breaker, you'd be screwed. Also, wasn't this inspected? The inspector should be able to look at the panel and see what each breaker is serving and make sure that none of the existing wiring had the breaker size changed accidentally, and that the new breakers were sized correctly according to the application as well. Right?

 

[brkaus]

@PoitNarf did they double they used the correct wire size for 50a?