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Home charge tripping breaker: Anyone?

james2441139

Member
Apr 8, 2021
32
16
Seattle
I have a NEMA 14-50 receptacle installed in my garage with a licensed electrician. With that, I have been using the Tesla Gen2 UMC for the last few months without any problems. The car (Model S 75D) charges fine at 32A with the Tesla UMC. I bought a new ChargePoint Home Flex and installed it myself, plugged in to the NEMA 14-50. In the ChagePoint app, I set the breaker amperage to 50A. When I connect the charger to the car, the car starts charging (blinking green), but after 2-3 seconds, the 50A breakers for the NEMA 14-50 trip. I have lowered the current draw in the car to 32A, but the breaker still trips. Is there any setting that I am missing with the ChargePoint Home Flex that is causing the breaker to trip?
 

ccdisce

EBISU like
Sep 10, 2014
234
111
Georgia USA
I have a NEMA 14-50 receptacle installed in my garage with a licensed electrician. With that, I have been using the Tesla Gen2 UMC for the last few months without any problems. The car (Model S 75D) charges fine at 32A with the Tesla UMC. I bought a new ChargePoint Home Flex and installed it myself, plugged in to the NEMA 14-50. In the ChagePoint app, I set the breaker amperage to 50A. When I connect the charger to the car, the car starts charging (blinking green), but after 2-3 seconds, the 50A breakers for the NEMA 14-50 trip. I have lowered the current draw in the car to 32A, but the breaker still trips. Is there any setting that I am missing with the ChargePoint Home Flex that is causing the breaker to trip?
You may want to talk to Charge Point.
You may want your licensed electrician check for a neutral line to the 14-50 outlet.
The Tesla UMC may not require a Neutral whereas the ChargePoint may require one.
Stay safe.
 
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croman

Active Member
Nov 21, 2016
4,913
7,145
Chicago, IL
EV charging doesn't require the extra neutral in a 6-50 plug but some electricians save a wire cost and don't use it for the 14-50 even though it's not safe to charge without it in 14-50 for a non-EV (think RVs).

So I agree with @ccdisce that it seems you might be well advised to contact you original electrician about this and see if you need them to fix their work and run an additional wire for neutral or to diagnose their work otherwise. Get a second opinion if this issues persists and the original electrician is unable or unwilling to immediately fix it.

This is a safety issue and your breaker is tripping to protect you.
 

james2441139

Member
Apr 8, 2021
32
16
Seattle
Thanks everyone for the valuable input. Contacted the electrician, will see what he says when he comes in. However, while researching, I found that ChargePoint and most other L2 chargers recommend that they be hardwired? If it is plugged in, there could be a GFCI conflict (if breaker has GFCI and the wall charger has GFCI). Have anyone encountered this GFCI issue causing breaker tripping while plugged in?
 
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dannycamps

Member
Apr 8, 2019
733
661
Northeast USA
Thanks everyone for the valuable input. Contacted the electrician, will see what he says when he comes in. However, while researching, I found that ChargePoint and most other L2 chargers recommend that they be hardwired? If it is plugged in, there could be a GFCI conflict (if breaker has GFCI and the wall charger has GFCI). Have anyone encountered this GFCI issue causing breaker tripping while plugged in?

**Standard disclaimer: not an electrician**

It's not true that the L2 EVSE has to be hard-wired. Another point of attack is to try the Chargepoint EVSE on a known good 14-50 outlet to see if it trips a breaker there. The fact that it works for 2-3 minutes and then trips makes me think it's getting too hot/pulling too much.

If it was a neutral issue, I'm pretty sure it would either trip the breaker immediately or would just give a ground fault error message. Would be interesting to see what would happen if you set it to 40A instead of 50A as someone above suggested.
 
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james2441139

Member
Apr 8, 2021
32
16
Seattle
**Standard disclaimer: not an electrician**

It's not true that the L2 EVSE has to be hard-wired. Another point of attack is to try the Chargepoint EVSE on a known good 14-50 outlet to see if it trips a breaker there. The fact that it works for 2-3 minutes and then trips makes me think it's getting too hot/pulling too much.

If it was a neutral issue, I'm pretty sure it would either trip the breaker immediately or would just give a ground fault error message. Would be interesting to see what would happen if you set it to 40A instead of 50A as someone above suggested.
Thanks for the tips. So it actually does not work for 2-3 minutes, more like 2-3 seconds before it trips. The NEMA 14-50 works fine with the Tesla Gen2 UMC, no tripping of the breaker.
I have set the ChargePoint app to 40A but it still tripped within couple of seconds.
 

GtiMart

Active Member
Nov 13, 2019
1,247
1,088
Quebec City, Canada
Are you sure the breaker for the 14-50 plug is a 50A? The mobile connector will charge at a maximum of 32A. If that works, maybe you have a 40A breaker at the other end? If so, 32A would be the limit for that circuit.
 

james2441139

Member
Apr 8, 2021
32
16
Seattle
Are you sure the breaker for the 14-50 plug is a 50A? The mobile connector will charge at a maximum of 32A. If that works, maybe you have a 40A breaker at the other end? If so, 32A would be the limit for that circuit.
Well the breaker says 50A on it and the inspector from the County verified so it should be a 50A breaker. I did change the current intake in the car to 32A but the breaker still trips with the ChargePoint.
 
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KArnold

Member
May 21, 2017
603
556
Columbus OH
On the Home Flex FAQ at ChargePoint Home Flex Installation FAQ | ChargePoint it says "Once an upgraded circuit is installed, use the mobile app to select Home Charger in the main menu, then Settings, and then Breaker Amperage".

I think peeps are suggesting you verify the Home Flex is set to only draw 40 amps. Looks like it's possible to run it at up to 50 amps.

That's different than the Tesla draw setting.
 

james2441139

Member
Apr 8, 2021
32
16
Seattle
On the Home Flex FAQ at ChargePoint Home Flex Installation FAQ | ChargePoint it says "Once an upgraded circuit is installed, use the mobile app to select Home Charger in the main menu, then Settings, and then Breaker Amperage".

I think peeps are suggesting you verify the Home Flex is set to only draw 40 amps. Looks like it's possible to run it at up to 50 amps.

That's different than the Tesla draw setting.
I actually have tried the 40A setting in the app as well, still tripping.
 

Bull

Supporting Member
Supporting Member
Oct 25, 2020
333
803
Tucson, AZ
Not sure if it is in your skillset but have you tried another breaker? Also, is a GFCI breaker required for your installation? If a non-GFCI breaker does not trip it will help you troubleshoot it. This is easier than finding another 14-50 and the circuit is likely good since you were using it before with the UMC.
 

james2441139

Member
Apr 8, 2021
32
16
Seattle
Not sure if it is in your skillset but have you tried another breaker? Also, is a GFCI breaker required for your installation? If a non-GFCI breaker does not trip it will help you troubleshoot it. This is easier than finding another 14-50 and the circuit is likely good since you were using it before with the UMC.
Haven't tried another breaker. I think this GFCI could be the issue. Found some similar problems over the web. I will wait for the electrician to have a look at it and hopefully determine the cause.
 

murphyS90D

Member
Jul 2, 2016
689
483
Horsham, PA
Didn't quite understand. Where's the dip switch?
Are you saying the only way to set the current is with an app? The Tesla HPWC has internal dip switches to set the maximum current. Without seeing a schematic I can only guess what they are doing.
Program the current with the EVSE not connected to the car. The car is only going to ask the EVSE once what the maximum value is for a given connection. If it is changed after that the car won't know it was changed. The question is does the EVSE have high current limiters or just a logic system that tells the car what the maximum is but has no way to enforce the current draw maximum? My guess, as a retired electrical/computer engineer, is the latter. The HPWC does it with dip switches so it can't be changed dynamically.
 

GtiMart

Active Member
Nov 13, 2019
1,247
1,088
Quebec City, Canada
@murphyS90D , you are correct for the Gen2 Tesla wall charger but the Gen3 does not have a physical switch anymore. The configuration of things like maximum power is done through a web page. This is why electricians insist on putting a 60A breaker, to support the potential maximum 48A delivery... because the configuration page is technically accessible by the end user.
I don't know how the ChargePoint works but it seems to be a web page too?

I otherwise agree with you, obviously, about setting the maximum on the charger with nothing plugged :)
 

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