Emporia Pro EVSE suddenly tripping breaker

[josh0]

I have an Emporia Pro EVSE that I’ve been using without problem for about a year. It’s wired to a 50A breaker, and set to pull a max of 40A, with one of their power monitors to keep it from drawing too much when there’s other large loads.

Last night, for the first time ever, it tripped the breaker, after charging for several hours. It was still about 20% away from my set SoC, so I gave it some time, the reset the breaker to continue charging. A couple hours later it tripped the breaker again.

It’s tripping its own breaker, not the main one for the sub-panel it’s in, and nothing else seems to be having any issues. Looking at the logs, at the time it tripped it was pulling right about 40A (more like 39.7) for a sustained period.

I was already in bed when it tripped the second time, so it’s still off, but my plan it to adjust the settings to 35A max, and try again.

Is there anything else I should be looking at? Could the breaker itself be wearing out after only a year of use (with several months of zero use when we weren’t here)? I’ve already got an electrician coming in for some other work soon (same guy who installed this in the first place), so I can have him take a look at it, too. Maybe replace the 50A breaker with a 60A for a little extra margin.

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[JacobAZ]

I suggest, On the Rivian drop the setting down to about 36. 40 amps is the max on a 50 amp breaker when running for hours. It may be borderline tripping. This may resolve the problem. Breakers do go bad, so this could be the issue. Do not replace with a 60 amp. The breaker is there to protect the wires. At 60 amp breaker should have 6 AWG or heavier. If the circuit was designed for 50 amp it is likely 8 awg

 

[josh0]

I suggest, On the Rivian drop the setting down to about 36. 40 amps is the max on a 50 amp breaker when running for hours. It may be borderline tripping. This may resolve the problem. Breakers do go bad, so this could be the issue. Do not replace with a 60 amp. The breaker is there to protect the wires. At 60 amp breaker should have 6 AWG or heavier. If the circuit was designed for 50 amp it is likely 8 awg

Should adjusting it on the Rivian make a difference compared to adjusting it on the EVSE? I guess I can try it both ways and see.

I’ll need to check with the electrician, but I had initially asked for a 60A circuit to be installed, so it’s possible the wiring is already appropriate for that amount of current. Obviously, I wouldn’t want to change it otherwise (the wiring is trenched through the yard to the car port, so changing it would be a real pain).

 

[Dark-Fx]

Check to make sure the terminals are still tight to spec at both ends. Breakers don't usually trip from 80% current unless there is something wrong.

 

[JacobAZ]

Should adjusting it on the Rivian make a difference compared to adjusting it on the EVSE? I guess I can try it both ways and see.

I’ll need to check with the electrician, but I had initially asked for a 60A circuit to be installed, so it’s possible the wiring is already appropriate for that amount of current. Obviously, I wouldn’t want to change it otherwise (the wiring is trenched through the yard to the car port, so changing it would be a real pain).

Adjusting the EVSE only should be fine if all is working propoerly The Rivian and EVSE negotiate. Rivian asks for current as it is set. The EVSE responds with how it is set. They should go with the lower of the two. But since you are trouble shooting, why not set both lower to see if it helps.

As for a 50 amp breaker tripping with 40 amps, this can be appropriate. Most house breakers trip based upon heat, not actual current. When pushing to the max heat will build up over time and will cause the breaker to trip if it exceeds its heat limit.

 

[josh0]

Check to make sure the terminals are still tight to spec at both ends. Breakers don't usually trip from 80% current unless there is something wrong.

Good call, I will definitely check that!

 

[josh0]

Adjusting the EVSE only should be fine if all is working propoerly The Rivian and EVSE negotiate. Rivian asks for current as it is set. The EVSE responds with how it is set. They should go with the lower of the two. But since you are trouble shooting, why not set both lower to see if it helps.

As for a 50 amp breaker tripping with 40 amps, this can be appropriate. Most house breakers trip based upon heat, not actual current. When pushing to the max heat will build up over time and will cause the breaker to trip if it exceeds its heat limit.

Heat from the load was my first thought, just because it was a more prolonged charge. Ironically, it may actually be because it was a cooler day than we’ve been having, so the charge wasn’t derated to accommodate the load from the air conditioner.

Hopefully adjusting the amperage down a bit will help, and then I’ll have the electrician double-check everything when he’s here.

 

[Zoidz]

If the breaker in the EVSE is tripping, and the 50A panel breaker is not tripping, there is ZERO value in upgrading to 60A even if the wiring can support it. There's no such thing as the 60A providing "extra margin" in this scenario.

Breakers already provide "extra margin" beyond their rating. A 50 amp breaker does not trip at 50 amps. For example, the trip cure below shows that a 50 amp breaker could take 30+ minutes at 52 amps to trip. At 125% = 62.5 amps, it takes 60 seconds before it will trip. In simple terms, the breaker is designed to heat up faster and thermal trip faster than the attached wiring would heat and burn on an smaller overcurrent. Short circuit magnetic trip is instantaneous. My point is - Increasing the breaker size in the panel is the wrong thing to do.

SInce you have stated that it is the breaker in the EVSE tripping, I think there are 4 possible issues:
1) The EVSE internal breaker is defective
2) The EVSE internal breaker is a GFCI and detecting a ground fault
3) The EVSE internal breaker is a GFCI and falsely tripping due to unrelated power line disturbances. It happens, but infrequently.
4) There is an overcurrent problem on the load side of the EVSE breaker.

Edit: I just looked up the specs of this EVSE. It does have internal GFCI.
Fast, Reliable, and Safe Charging: Up to 48 amps of power for swift, consistent Level 2 charging across all EV models. UL certified and GFCI-protected.

 

[josh0]

If the breaker in the EVSE is tripping, and the 50A panel breaker is not tripping, there is ZERO value in upgrading to 60A even if the wiring can support it. There's no such thing as the 60A providing "extra margin" in this scenario.

Breakers already provide "extra margin" beyond their rating. A 50 amp breaker does not trip at 50 amps. For example, the trip cure below shows that a 50 amp breaker could take 30+ minutes at 52 amps to trip. At 125% = 62.5 amps, it takes 60 seconds before it will trip. In simple terms, the breaker is designed to heat up faster and thermal trip faster than the attached wiring would heat and burn on an smaller overcurrent. Short circuit magnetic trip is instantaneous. My point is - Increasing the breaker size in the panel is the wrong thing to do.

SInce you have stated that it is the breaker in the EVSE tripping, I think there are 4 possible issues:
1) The EVSE internal breaker is defective
2) The EVSE internal breaker is a GFCI and detecting a ground fault
3) The EVSE internal breaker is a GFCI and falsely tripping due to unrelated power line disturbances. It happens, but infrequently.
4) There is an overcurrent problem on the load side of the EVSE breaker.

Sorry, I should clarify. The 50A breaker in the panel is tripping. It is not a GFCI, and the reporting from the energy monitor installed in the panel reports that the load from the EVSE never exceeds 40A, and that both times the breaker has tripped have been after extended periods of ~40A load. So it seems that either:

1) the breaker is faulty and tripping at too low a current,
2) the sustained 40A load is generating enough heat to trip the breaker regardless of current, or
3) the monitor is incorrectly reporting the load, and it is actually higher than 40A.

My guess is that it’s either 1 or 2 (possibly both). If the wiring that was installed was the correct wiring for the 60A circuit I initially requested, and not the 50A one that was installed, then it seems like replacing the breaker with the higher capacity option would be a good solution to both problems 1 and 2 (plus give me the option to charge 20% faster). Otherwise, a new 50A breaker should also work, assuming there’s no other issues involved.

 

[Zoidz]

Sorry, I should clarify. The 50A breaker in the panel is tripping. It is not a GFCI, and the reporting from the energy monitor installed in the panel reports that the load from the EVSE never exceeds 40A, and that both times the breaker has tripped have been after extended periods of ~40A load. So it seems that either:

1) the breaker is faulty and tripping at too low a current,
2) the sustained 40A load is generating enough heat to trip the breaker regardless of current, or
3) the monitor is incorrectly reporting the load, and it is actually higher than 40A.

My guess is that it’s either 1 or 2 (possibly both). If the wiring that was installed was the correct wiring for the 60A circuit I initially requested, and not the 50A one that was installed, then it seems like replacing the breaker with the higher capacity option would be a good solution to both problems 1 and 2 (plus give me the option to charge 20% faster). Otherwise, a new 50A breaker should also work, assuming there’s no other issues involved.

OK, to me it read like there was an internal EVSE tripping. The 40A load should never create enough heat to trip a 50 amp breaker unless the breaker is defective. However, with the installation clarified, the problem could be the breaker overheating because one of the wires attached to the breaker was not installed/torqued properly and is heating up. Even if it was installed properly, with larger wire sizes, it is still possible for the copper wire to "rest" after repeated power cycles and become less secure. That heat combined with the "normal" breaker heat will definitely thermally trip a breaker - I've seen this scenario in my work. Personally, I would not use it until you have it checked. If it is a loose wire at the EVSE, it could be a fire hazard and the breaker is doing it's job.

 

[josh0]

OK, to me it read like there was an internal EVSE tripping. The 40A load should never create enough heat to trip a 50 amp breaker unless the breaker is defective. However, with the installation clarified, the problem could be the breaker overheating because one of the wires attached to the breaker was not installed/torqued properly and is heating up. Even if it was installed properly, with larger wire sizes, it is still possible for the copper wire to "rest" after repeated power cycles and become less secure. That heat combined with the "normal" breaker heat will definitely thermally trip a breaker - I've seen this scenario in my work. Personally, I would not use it until you have it checked. If it is a loose wire at the EVSE, it could be a fire hazard and the breaker is doing it's job.

I will definitely get it checked, thanks!

 

[FLLDEA]

I didn't see this info in anybody's response. If you do change the breaker to 60 amps I think the requirement is to have the EVSE hardwired. I think you can only use a NEMA 15-50 up to 50A breaker. That also could be a problem now if you have a plug. there could be a bad connection at the plug. People have used cheep receptacles and they burn up.

 

[josh0]

It’s hardwired already, we’re in a high fire risk area, and pretty far out in the middle of nowhere, so I wanted to minimize the chance of issues.

 

[Dasoss]

I have an Emporia Pro EVSE that I’ve been using without problem for about a year. It’s wired to a 50A breaker, and set to pull a max of 40A, with one of their power monitors to keep it from drawing too much when there’s other large loads.

Last night, for the first time ever, it tripped the breaker, after charging for several hours. It was still about 20% away from my set SoC, so I gave it some time, the reset the breaker to continue charging. A couple hours later it tripped the breaker again.

It’s tripping its own breaker, not the main one for the sub-panel it’s in, and nothing else seems to be having any issues. Looking at the logs, at the time it tripped it was pulling right about 40A (more like 39.7) for a sustained period.

I was already in bed when it tripped the second time, so it’s still off, but my plan it to adjust the settings to 35A max, and try again.

Is there anything else I should be looking at? Could the breaker itself be wearing out after only a year of use (with several months of zero use when we weren’t here)? I’ve already got an electrician coming in for some other work soon (same guy who installed this in the first place), so I can have him take a look at it, too. Maybe replace the 50A breaker with a 60A for a little extra margin.

It could be because it's summer. The charger's breaker might be sensitive to temperature.

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