60A breaker melted while charging

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Melting circuit breaker can only be explained by bad circuit breaker or bad installation of circuit breaker.

A defective charger would cause the circuit breaker to trip, not melt.

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[Dark-Fx]

I'd make sure your panel backplane isn't damaged.

 

[HaveBlue]

Likely the bus bar is/was corroded and making a bad connection. If you didn't fix that and are also just tossing in random used breakers, get ready for a repeat shortly. Do you have an Eaton panel? An old Bryant or Cutler panel could have many years on it and need a look. I prefer Siemens q series as compatible replacements if your panel allows it.

 

[SanDiegoR1S]

Has anyone had issues with faulty wall chargers that could have caused breakers to literally melt. Truck was set at 48A and was wired to spec. Reinstalled 50A breaker and dialed back to 40A. Breaker still gets slightly warm and very faint buzzing. Wondering if there are faulty wall chargers out there.

Did you get any definitive explanation? And did you contact Rivian about the charger?

I ask because this just happened to me too. My electrician is licensed and installs EV chargers all day, including Rivian chargers, and he said he's never had this happen. He double checked all his work, tried a new breaker in case the other one was faulty, and in the end said he tested it and the charger was pulling 55 amps when it's supposed to stop at 48, so it must be a defective charger. I reported it to Rivian but they told me the charging team is so swamped with high priority tickets that they can't say when they'll get back to me.

 

[Dark-Fx]

Did you get any definitive explanation? And did you contact Rivian about the charger?

I ask because this just happened to me too. My electrician is licensed and installs EV chargers all day, including Rivian chargers, and he said he's never had this happen. He double checked all his work, tried a new breaker in case the other one was faulty, and in the end said he tested it and the charger was pulling 55 amps when it's supposed to stop at 48, so it must be a defective charger. I reported it to Rivian but they told me the charging team is so swamped with high priority tickets that they can't say when they'll get back to me.

Truck isn't supposed to be able to pull more than 48A. That said, 55A shouldn't be enough to cause issues unless there is an error in the installation.

 

[Jimbydude]

The whole point of breaker is to trip if overloaded so a defecrive charger should still trip, not melt breaker.

 

[Glongo]

Has anyone had issues with faulty wall chargers that could have caused breakers to literally melt. Truck was set at 48A and was wired to spec. Reinstalled 50A breaker and dialed back to 40A. Breaker still gets slightly warm and very faint buzzing. Wondering if there are faulty wall chargers out there.

100% it’s a “loose” lug. Use a torque driver! The loosenesses causes an arc. It’s like an arc welder…….

 

[Zoidz]

The whole point of breaker is to trip if overloaded so a defecrive charger should still trip, not melt breaker.

Did you get any definitive explanation? And did you contact Rivian about the charger?

I ask because this just happened to me too. My electrician is licensed and installs EV chargers all day, including Rivian chargers, and he said he's never had this happen. He double checked all his work, tried a new breaker in case the other one was faulty, and in the end said he tested it and the charger was pulling 55 amps when it's supposed to stop at 48, so it must be a defective charger. I reported it to Rivian but they told me the charging team is so swamped with high priority tickets that they can't say when they'll get back to me.

The whole point of breaker is to trip if overloaded so a defecrive charger should still trip, not melt breaker.

You didn’t mention what your breaker is rated at.

The amperage rating for a breaker is the MINIMUM current it will carry continuously, NOT the trip current. By design and specification, a 60 amp breaker may take 2 or more hours to trip at 120% current/which is 72 amps, in fact it may never trip at all. This is easily determined by looking at the breake trip curve documentation. Your experienced electrician should know this. He should also know that the #1 cause of melted breakers is poor connections, not a defective breaker or EVSE drawing 7% more than its expected amount.

 

[CharonPDX]

You didn’t mention what your breaker is rated at.

The amperage rating for a breaker is the MINIMUM current it will carry continuously, NOT the trip current. By design and specification, a 60 amp breaker may take 2 or more hours to trip at 120% current/which is 72 amps, in fact it may never trip at all. This is easily determined by looking at the breake trip curve documentation. Your experienced electrician should know this. He should also know that the #1 cause of melted breakers is poor connections, not a defective breaker or EVSE drawing 7% more than its expected amount.

This. Enel-X decided to make the excellent JuiceBox 40s I have into useless wall-mounted piles of garbage with their "software update" last year. The reason I bought the JB40s was because they supported load sharing. I put two 40A EVSEs on one 60A circuit, and told them to split 48A. When I plug in one EV, it gets the full 40A its individual JuiceBox can output. If I plug in two, they each get 24A. (Or a split based on the draw requested by each; as one gets close to full, it will draw less power, and make more available to the other vehicle.) Enel-X's update to their new software broke load balancing.

The first time, it set both units to 7A. It turns out one of my EVs couldn't charge on 7A at all, I thought the JuiceBoxes were totally broken until I plugged in a vehicle that could dial down to 7A, and it charged fine. I got Enel-X to revert me to the old software.

The second time, they lost load sharing. One unit just set itself to 24A maximum no matter what, the other to 40A maximum no matter what. I plugged in two vehicles, and was instantly drawing 64A. (I saw on my Rivian's display that it was charging faster than it should be with two vehicles plugged in.) I waited a couple minutes, and it was still drawing 64A. I decided that was enough and unplugged. My breaker never tripped. Note: The breaker started acting up a few months later!

 

[SparkyR1t]

Your photo is indicative of a loose connection that began heating and eventually failed. Were you using stranded 6awg copper wire. I routinely scan my high current connections while under load with a non contact thermometer. ( after initial install and then yearly) to verify normal heating is occurring. Ideally around 65C but never greater than 75C. There are also poor quality circuit breakers available online that are prone to early failure. I would inspect all connections on this circuit and install a name Rand breaker and then take temp readings while in operation if you are comfortable doing this safely

 

[DrMario]

I had one melt after installation by electrician. Got a new breaker from Lowes and it still got very hot to the touch. Called the electrician back and he could not find anything wrong with the wiring or the installation. Called Rivian and basically said it was nothing on their end.

As a last resort, I figured it may be a cheaply made breaker just like what the breaker the electrician used initially. Bought one of the breakers recommended on the breaker box spec sheet which cost twice as much as the one from Lowes and everything has been working fine for the past 2 years since I've had it.

Maybe this will help.

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