EV charger breaker overheating

[don_resqcapt19]

The Emporia EV charger has built in GFCI. It does a self-test every so often. Emporia tech support confirmed that when the EV charger performs a self-test, it will trip the GFCI breaker since the breaker tolerance is only 5mA.

Ok, I did not understand that you had a GFCI breaker, but should have since you said it is cord connected and the receptacle requires GFCI protection.

 

[retirede]

The plug of the EV charger that goes into the 14-50 receptacle is also hot. 137 degrees.

Would a bad breaker cause the plug to be hot?

If you search the forum, you’ll find threads where we’ve discussed problems with cheap 14-50 receptacles overheating when used to supply EVSEs. This may be unrelated to the breaker tripping problem.

 

[SR59]

If you search the forum, you’ll find threads where we’ve discussed problems with cheap 14-50 receptacles overheating when used to supply EVSEs. This may be unrelated to the breaker tripping problem.

I made sure to use a Hubbell/Bryant heavy duty 14-50 receptacle. This is the receptacle brand recommended by Tesla.

 

[don_resqcapt19]

I think both heat issues are a result of poor connections at some point in the area of the excessive heat. For the breaker it could be the breaker to bus connection, or the actual internal breaker contacts. For the receptacle it is most likely poor contact pressure between the receptacle socket and the plug blades. This it the issue in the cheap receptacles mentioned in post 22.

 

[SR59]

I think both heat issues are a result of poor connections at some point in the area of the excessive heat. For the breaker it could be the breaker to bus connection, or the actual internal breaker contacts. For the receptacle it is most likely poor contact pressure between the receptacle socket and the plug blades. This it the issue in the cheap receptacles mentioned in post 22.

 

[SR59]

The breaker to bus connection is tight. No arcing marks or discoloration.

I made sure to use a Hubbell/Bryant heavy duty 14-50 receptacle. This is the receptacle brand recommended by Tesla. Plug blades are very tight.

I checked the torque on all the connections.

In the thermal camera, the heat is highest in the center of the breaker. So it might be the internal breaker contacts.

 

[SR59]

I think both heat issues are a result of poor connections at some point in the area of the excessive heat. For the breaker it could be the breaker to bus connection, or the actual internal breaker contacts. For the receptacle it is most likely poor contact pressure between the receptacle socket and the plug blades. This it the issue in the cheap receptacles mentioned in post 22.

The breaker to bus connection is tight. No arcing marks or discoloration.

I made sure to use a Hubbell/Bryant heavy duty 14-50 receptacle. This is the receptacle brand recommended by Tesla. Plug blades are very tight.

I checked the torque on all the connections.

In the thermal camera, the heat is highest in the center of the breaker. So it might be the internal breaker contacts.

 

[don_resqcapt19]

The breaker to bus connection is tight. No arcing marks or discoloration.

I made sure to use a Hubbell/Bryant heavy duty 14-50 receptacle. This is the receptacle brand recommended by Tesla. Plug blades are very tight.

I checked the torque on all the connections.

In the thermal camera, the heat is highest in the center of the breaker. So it might be the internal breaker contacts.

The only thing that makes heat is current flowing through resistance. There is higher than normal resistance in both the breaker and the receptacle.
The test in post 4 would give you an idea about the breaker, but there is not an easy way to do that at the receptacle.

 

[jim dungar]

In the thermal camera, the heat is highest in the center of the breaker. So it might be the internal breaker contacts.

This makes sense. The hotest spot on a circuit breaker should be its operating mechanism which located in the center of a multi-pole breaker, per UL and NEMA standards. I recall this temp can be around 60°C on a fully loaded breaker while lugs will be less than 50°C.

 

[Joethemechanic]

The Emporia EV charger has built in GFCI. It does a self-test every so often. Emporia tech support confirmed that when the EV charger performs a self-test, it will trip the GFCI breaker since the breaker tolerance is only 5mA.

What does the charger's built in GFCI tripping have to do with the breaker in the panel tripping? Are you saying that when the carger's GFCI trips, the breaker in the panel also trips?

 

[wwhitney]

When the breaker is tripping, what's the ambient temperature in the room with the panelboard, and what's the ambient temperature within the panel away from the breakers? Is the breaker panel in an exterior wall, and is that wall in full sun? Does the breaker trip when charging starts after sunset?

Cheers, Wayne

 

[Joethemechanic]

The only thing that makes heat is current flowing through resistance. There is higher than normal resistance in both the breaker and the receptacle.
The test in post 4 would give you an idea about the breaker, but there is not an easy way to do that at the receptacle.

Yeah, breaker hot, receptacle hot, has to be loose or poor connections. Unless it's two defective devices.

Maybe the supply house got flooded by the sea

 

[Little Bill]

Since the OP is not an electrician, or in the electrical industry, we've helped as much as we can.
OP, please contact an electrician that is familiar with EV chargers.