Tesla wall connector gen3 overheating fix

[Sophias_dad]

Ok. The engineer in me is gonna drive me nuts if I keep staring at this. What do we believe to be the normal operating temperature of the gen 3 when charging at 48A. I have the wall monitor app measuring the PCB, Handle, etc. As well as a temperature gun.

I have read the trip temperature (three red lights) to be ~200F on the PCB and 110F on the handle. Agree?

Regardless of that, what do we see as nominal during 48A charging for multiple hours (evened out steady state)?

I have several samples of 'good' 48 amp multi-hour charge sessions on different HPWC's. The 'normal' temperature of my samples is suggesting a plateau of maybe ~145F with good relays and the HPWC in a shaded garage at ~70F. I don't recall the handle temps, but 110F seems reasonable. I don't know where the HPWC will start throttling, but it looks like you've found that to be perhaps 200F. For reference, 75C is 167F, while 90C is 194F.

The relays on Gen3 HPWCs models ending in -F and before are known to be dubious. Each of the two relays has two contactors in it, and if one is notably better than the other, the relay will overheat and may eventually completely fail.

 

[josahua]

I have several samples of 'good' 48 amp multi-hour charge sessions on different HPWC's. The 'normal' temperature of my samples is suggesting a plateau of maybe ~145F with good relays and the HPWC in a shaded garage at ~70F. I don't recall the handle temps, but 110F seems reasonable. I don't know where the HPWC will start throttling, but it looks like you've found that to be perhaps 200F. For reference, 75C is 167F, while 90C is 194F.

The relays on Gen3 HPWCs models ending in -F and before are known to be dubious. Each of the two relays has two contactors in it, and if one is notably better than the other, the relay will overheat and may eventually completely fail.

Thank you. Last night I ran it for 4 hours at 48A and it evened out at 150F PCB and 106F Handle. Good to have a solid comparison.

 

[--1--]

This is a follow-up to my defective HPWC post. I received my second replacement Tesla Gen 3 J1772 HPWC this week. With little confidence in this product, I decided to reduce the amperage and replaced my 60A circuit breaker with a 50A, along with a 50A setting in the commissioning process. Installed the new HPWC and charged my Bolt to 90% without issues. I did notice the circuit breaker is still warm to the touch along with the HPWC charge cable. Fairly mild temperature day. The real test will be on hot summer days. I'm disappointed with my Gen 3 HPWC experience. I'm a firm believer in charging my EVs at the fastest possible speed. Tesla tech support was very quick to send replacements without issues. I'll monitor future use.

Two weeks later, my third new Tesla HPWC J1772 Model, and another three red light fault halfway through charging. Original configuration 6g THNN, 60A breaker, configured for 48A. With the third new HPWC second replacement, I decided to reduce power with a 50A breaker, configured for 40A use. Worked fine first almost full charge last week. Yesterday, halfway through, I get three red lights. Will contact Tesla support today.

 

[--1--]

This is my Tesla Gen 3 charging experience. Three new Gen 3 model J1772 HPWC and the same results, ongoing for two months. Tesla's solution is to send a new HPWC. Last week they pushed a firmware update that didn't fix the issue. I've replaced the 60A breaker with a fifty and reduced the charging amperage in the charging app to 40A. Same result. I was on the phone with Tesla charging support yesterday and now they telling me that when the Gen 3 HPWC senses overheating, it displays three flashing red lights and pauses charging. Daytime temperatures Sunday were high seventies with garage doors open, and still resulted in overheating and charging stopped. Tesla is now telling me this is normal. I shouldn't have to reduce charging amperage to make it work without faulting. I referenced this site and this charging thread to Tesla. Relacing defective HPWC with like items isn't the fix.

 

[paulchou]

What's the operating temperature for the 60amp breaker for the wall connector? I had an old wall connector that was fried so I am very cautious about overheating. Tesla just sent me a new one, everything works well so far - and the handle/MCU all seemed cooler - except the breaker switch (at the main swithbox) is VERY hot to the touch. I seem to recalled the old one wasn't THAT hot? In any case, I used an infrared heat gun and it showed 165F after one hour and as high as 175F after 1.5 hrs of charging.

But according to this below, max temperature on non-metal handle can be 85C (or 185F) so I am still ok?

The wiring should be good, as I had the electrician came out last year to checking for loose connections, etc.

Curious to see what others see at the breaker temperature wise.

How hot can circuit breakers get? What is the temperature of a molded case breaker? | Schneider Electric USA

 

[DerbyDave]

I would be concerned if anything got too hot to touch at any time.

 

[Sophias_dad]

But according to this below, max temperature on non-metal handle can be 85C (or 185F) so I am still ok?

Unless its very hot in Austin right now, I wouldn't expect the face/handle of the breaker to get all that hot, but if the manufacturer says its okay I guess its okay. I can tell you that my 60 amp breaker doesn't go beyond 'warm' when running for hours, but its in a 60F basement. I'll get an actual measurement later today.

 

[paulchou]

It is very hot in Texas this summer, 40+ days 100+ degrees. But still, I don't think it's supposed to be this hot. I'll get it check out again.

 

[Supcom]

It is very hot in Texas this summer, 40+ days 100+ degrees. But still, I don't think it's supposed to be this hot. I'll get it check out again.

If charging in afternoon sun in Texas summer, my Wall Connector handle will report temp in excess of 150F resulting in a temperature foldback from 40A to 20A. My low tech solution is to restart charging after setting a wet rag on the handle. Shading the handle from direct solar radiation might be sufficient, but the wet rag is simple and effective. Even better is to wait until evening to start charging. Best yet, is to schedule charging after 10 PM, if feasible, to avoid peak demand on the power grid.

 

[TBrownTX]

If charging in afternoon sun in Texas summer, my Wall Connector handle will report temp in excess of 150F resulting in a temperature foldback from 40A to 20A. My low tech solution is to restart charging after setting a wet rag on the handle. Shading the handle from direct solar radiation might be sufficient, but the wet rag is simple and effective. Even better is to wait until evening to start charging. Best yet, is to schedule charging after 10 PM, if feasible, to avoid peak demand on the power grid.

That's how I am handling, have charging set for 2AM.

 

[Sophias_dad]

It is very hot in Texas this summer, 40+ days 100+ degrees. But still, I don't think it's supposed to be this hot. I'll get it check out again.

The face of my 50A breaker running 48A continuously(ya, you read that right!) for 2+ hours in my 65F basement is 105F. If I look REALLY hard I can find a 110F spot.

 

[paulchou]

Not sure what happened to my other post morning, but here's an update:

So this morning after opening up the breaker box, I found part of the insulation strip behind the Tesla charger breaker melted. I called a couple of electricians, asking for a quote, they all tell me that the insulation is part of the panel, and that I need to replace the whole panel, for a mere fee of ... $4k. (Bullshit!)

It got me thinking, since I am not short on slots - why don't I just rearrange the other breakers, and leave that partially melted one strip out? Problem solved! It only cost me $10, and that's for 4 breaker slot filler plates (the pic below was before I put on the cover plates).

I just tested it out: max temperature on the breaker handle is about 156 F, after 1 hr and 15 mins of charging - still hot, but keep in mind this is in 102 F Texas afternoon heat, and way better than last night's 18 5F after similar time of charging.

That's all I am gonna do. After labor day I might swap out the breakers to see if that makes a difference.

Going forward, I am going to set the charger to 32 amps, unless I am in a rush, and charge it after midnight only (at least in Texas summer).

 

[paulchou]

The face of my 50A breaker running 48A continuously(ya, you read that right!) for 2+ hours in my 65F basement is 105F. If I look REALLY hard I can find a 110F spot.

so it's basically 50 F above your basement's ambient temperature of 60. given the ambient temperature in Texas is now 100+, 156F might not be too bad after all.

I am curious to see other ppl's data pts, especially in hotter climates...

 

[MP3Mike]

so it's basically 50 F above your basement's ambient temperature of 60. given the ambient temperature in Texas is now 100+, 156F might not be too bad after all.

He is running the breaker past the design guidelines. I would expect that if he put a 60A breaker in, which is correct for a continuous 48A load, that it would run cooler. (The breakers use heat as part of the overcurrent trigger, so running it just under 2A of the rating is going to generate more heat than if you are running it 12A below the rating.)

 

[Supcom]

The face of my 50A breaker running 48A continuously(ya, you read that right!) for 2+ hours in my 65F basement is 105F. If I look REALLY hard I can find a 110F spot.

Change the batteries in your smoke detectors.