EV Charging Circuit - Breaker Hot | on ElectriciansForums

Discuss EV Charging Circuit - Breaker Hot in the UK Electrical Forum area at ElectriciansForums.net

hifiandy

DIY
Joined
Sep 1, 2022
Messages
3
Reaction score
0
Location
Wichita, KS
I installed a new 50 amp circuit to charge my EV.

Some specifics on the circuit - 50 amp breaker, 6-2 ga copper wire (UFB because in the future I may place the charger outside and wanted flexibility), NEMA 6-50 plug, Grizzl-e charger at 40 amps.

My question is on the breaker itself. I have a GE load center and installed a THQP250 breaker which is the thin line 50 amp breaker and verified torque to the 35 in.lbs. specified on the breaker. My other breakers are also the thin line series and space is tight in my panel. When charging, my breaker is at 125F temperature, which is about 45F over the rest of the panel. While I believe this is per UL, it still seems higher than it should be. I think the obvious first step is to replace the breaker with an equivalent, which I'm planning to do, but my real question is there a heavy duty breaker that should be used in this application?

Appreciate the input.
 
I installed a new 50 amp circuit to charge my EV.

Some specifics on the circuit - 50 amp breaker, 6-2 ga copper wire (UFB because in the future I may place the charger outside and wanted flexibility), NEMA 6-50 plug, Grizzl-e charger at 40 amps.

My question is on the breaker itself. I have a GE load center and installed a THQP250 breaker which is the thin line 50 amp breaker and verified torque to the 35 in.lbs. specified on the breaker. My other breakers are also the thin line series and space is tight in my panel. When charging, my breaker is at 125F temperature, which is about 45F over the rest of the panel. While I believe this is per UL, it still seems higher than it should be. I think the obvious first step is to replace the breaker with an equivalent, which I'm planning to do, but my real question is there a heavy duty breaker that should be used in this application?

Appreciate the input.
I’m surprised that your breaker hasn’t Tripped yet. You need to put an amp meter to see exactly what kind of load you are actually pulling. You are not allowed to use over 80% of the breaker size. Good luck
 
I’m surprised that your breaker hasn’t Tripped yet. You need to put an amp meter to see exactly what kind of load you are actually pulling. You are not allowed to use over 80% of the breaker size. Good luck

I put a clamp meter on the circuit and it is pulling 41 amps, which was expected as the charger is rated at 40 amps and there's no indication it is not functioning properly. So, the two questions still remain.

1. Is the breaker temp of 125F reason to be concerned (+45F over nominal)?
2. Should I replace the breaker with a thin-line equivalent or possibly switch to the full-size equivalent which would take a fair amount of work to move other breakers and make space?

Thanks
 
I put a clamp meter on the circuit and it is pulling 41 amps, which was expected as the charger is rated at 40 amps and there's no indication it is not functioning properly. So, the two questions still remain.

1. Is the breaker temp of 125F reason to be concerned (+45F over nominal)?
2. Should I replace the breaker with a thin-line equivalent or possibly switch to the full-size equivalent which would take a fair amount of work to move other breakers and make space?

Thanks
I put a clamp meter on the circuit and it is pulling 41 amps, which was expected as the charger is rated at 40 amps and there's no indication it is not functioning properly. So, the two questions still remain.

1. Is the breaker temp of 125F reason to be concerned (+45F over nominal)?
2. Should I replace the breaker with a thin-line equivalent or possibly switch to the full-size equivalent which would take a fair amount of work to move other breakers and make space?

Thanks
That is really high to continually be pulling 41 amps and it will break down your breaker over time. Try like you said a install a regular size breaker and see if it cools down.
I put a clamp meter on the circuit and it is pulling 41 amps, which was expected as the charger is rated at 40 amps and there's no indication it is not functioning properly. So, the two questions still remain.

1. Is the breaker temp of 125F reason to be concerned (+45F over nominal)?
2. Should I replace the breaker with a thin-line equivalent or possibly switch to the full-size equivalent which would take a fair amount of work to move other breakers and make space?

Thanks
I think that you need to take the slimline breaker out and bump your breaker up to a regular size 60 amp breaker which should cool it down significantly.
 
I moved some breakers to make room for a full-size 50 amp breaker for my EV charger circuit. While a bit of work, the new full-size breaker is at 107F (still a nominal temp in the panel of 80F) after fully warmed up and has been charging over an hour. I am much happier with this temperature, it feels warm to the touch but not hot as previously. EV chargers are a unique load case because they can pull full amperage (80% of circuit per code) for literally 8 hours straight. I did not increase the breaker size to 60 amp because both the wiring and receptacle are rated for 50 amps and increasing the breaker to 60 amp would be a code violation. While working on it I did take some pictures of both the slim-line and full-size breakers to see the contact area and the conclusion I reached is that slim-line breakers are not preferable for this type of application, due to the limited contact area with the bus bar. Pictures attached for reference.
 

Attachments

  • [ElectriciansForums.net] EV Charging Circuit - Breaker Hot
    IMG-1187.jpg
    383.8 KB · Views: 23
  • [ElectriciansForums.net] EV Charging Circuit - Breaker Hot
    IMG-1188.jpg
    445.3 KB · Views: 29
  • [ElectriciansForums.net] EV Charging Circuit - Breaker Hot
    IMG-1190.jpg
    348.9 KB · Views: 32
  • [ElectriciansForums.net] EV Charging Circuit - Breaker Hot
    IMG-1191.jpg
    289.8 KB · Views: 31
  • [ElectriciansForums.net] EV Charging Circuit - Breaker Hot
    IMG-1193.jpg
    370.1 KB · Views: 29
I moved some breakers to make room for a full-size 50 amp breaker for my EV charger circuit. While a bit of work, the new full-size breaker is at 107F (still a nominal temp in the panel of 80F) after fully warmed up and has been charging over an hour. I am much happier with this temperature, it feels warm to the touch but not hot as previously. EV chargers are a unique load case because they can pull full amperage (80% of circuit per code) for literally 8 hours straight. I did not increase the breaker size to 60 amp because both the wiring and receptacle are rated for 50 amps and increasing the breaker to 60 amp would be a code violation. While working on it I did take some pictures of both the slim-line and full-size breakers to see the contact area and the conclusion I reached is that slim-line breakers are not preferable for this type of application, due to the limited contact area with the bus bar. Pictures attached for reference.
Them slim line breakers contacts I’m not sure that they can carry current like the regular size. Just keep up with your new breaker on the heating up. It should not be warm to the touch. It needs to be a bigger service
 
Them slim line breakers contacts I’m not sure that they can carry current like the regular size. Just keep up with your new breaker on the heating up. It should not be warm to the touch. It needs to be a bigger service

Why shouldn't it be warm?

All circuit breakers, fuses, cables etc get warm when working, in fact almost everything that conducts electricity will get warm when current is flowing.
 

Reply to EV Charging Circuit - Breaker Hot in the UK Electrical Forum area at ElectriciansForums.net

News and Offers from Sponsors

  • Article
Join us at electronica 2024 in Munich! Since 1964, electronica has been the premier event for technology enthusiasts and industry professionals...
    • Like
Replies
0
Views
252
  • Sticky
  • Article
Good to know thanks, one can never have enough places to source parts from!
Replies
4
Views
724
  • Article
OFFICIAL SPONSORS These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then...
Replies
0
Views
696

Similar threads

  • Question
I won't mention the one I came across once, then. The outer sheath of the element had dissolved and the element spiral had shorted to the sheath...
2 3
Replies
34
Views
5K
  • Question
I think it is my old system.. The electricians were from Qmerit that works with GM, they came to the house looked it over before agreeing to do...
2
Replies
23
Views
2K

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

YOUR Unread Posts

This website was designed, optimised and is hosted by untold.media Operating under the name Untold Media since 2001.
Back
Top