Home charging now stepping down to 24 amps during the charging session

[eddieb3]

UPDATE: This morning I started charging the M3 and monitored it via the app about every 3-5 minutes. It started out fine at 48 amps and 44-45 miles of range per hour. It dropped down to 24 amps at about the 55 minute mark. At that point, I looked at the display and there was a message: "Charging speed reduced High temperature detected by Wall Connector" (pictures attached) which confirms the theory made by several of you. Never saw that message before, but never looked at the display immediately after the drop off happened either.

I have found a post on another forum that had this same problem with a new M3. But he also already owned another M3 and this problem is non-existent with that car which implies the problem is with the car. But found several other posts where the problem was with the wiring or wall charger (loose wires, low gauge). I have a friend nearby with a MS. I'm going to charge his car on my charger to see if his car experiences the same thing. If it does, then it's not the car and I will bring in my electrician to look at things. If his car charges OK with no drop off, then I will call Tesla for a service appointment. I'll update here as I find out more. Thanks everyone.

 

[Dave Mac]

This happened to me last week… The cord going into the wall connector was definitely warm. I opened it he wall connector and it turned out the wire contact into the main terminals was not good and/or had become loose.

 

[eddieb3]

This happened to me last week… The cord going into the wall connector was definitely warm. I opened it he wall connector and it turned out the wire contact into the main terminals was not good and/or had become loose.

I'm testing the charging with my friend's MS right now to see if it's the car or the wall connector/charger. If it's the charger, I will open it up and check for loose connections before contacting the electrician. Thanks

 

[RayK]

Sounds like a thermal problem to me. <snip>

At that point, I looked at the display and there was a message: "Charging speed reduced High temperature detected by Wall Connector" (pictures attached) which confirms the theory made by several of you. <snip>

You're welcome Sorry I don't have any other recommendation other than double-check the wiring from the wall connector all the way back to the main panel. Oh, see if you can determine what the wire gauge is.

 

[Fernand]

Is there a 5G tower nearby? ....

 

[Pluturi]

If you aren't already, you might want to keep track of this thread also. It sounds like a similar problem.
Gen 3 cord 23 degree temp rise in 10 minutes :(

 

[Pluturi]

And another one. This one has a phone number which might be helpful. Sounds like a lot of people are having similar problems.

https://teslamotorsclub.com/tmc/threads/gen-3-wall-connector-3-red-blinks-fault-code.198052/

 

[Watts 4 Me]

My wall charge started acting up as well. It was working for over a year with no problems. Then it started cutting my charge rate in half. The T would blink 3 times. My charger is open to the elements.

 

[smartypnz]

Sorry to be late to this...
Same experience - about a year ago. Our setup was to a 50 Amp circuit, so max charge was at 40 Amps. Been in use now for 7 years - so Gen 1.
Anyway, it would scale down to 32 Amps, then 24. A combination of problems... Our voltage would fluctuate some nights (causing the sensors to drop the charge rate) - and the cable connectors were getting (dirty?).

Tesla couldn't figure it out - but we cleaned the connectors with an electrical contact spray (let it dry) and dialed back our current to 30 Amps. Still was enough to charge overnight. We still occasionally spray clean the contacts for all our cable connectors as well as adapters.

Alternative fix was replacing main electrical box (haha) - wouldn't stop PG&E fluctuations in voltage at night.

Funny, though. The M3 never had a problem with it. Both MS's did. But I mostly charge the M3 on 120v (generally only put 12 miles on it per day). Wife needs 200 - 270 or so on her MS for work.

 

[eddieb3]

And another one. This one has a phone number which might be helpful. Sounds like a lot of people are having similar problems.

https://teslamotorsclub.com/tmc/threads/gen-3-wall-connector-3-red-blinks-fault-code.198052/

Thanks for the other thread links. Seems like a lot of people have the same issues. Seems most is with the gen 3 but also gen 1 and 2 as well. I was concerned that mine going out after two years of no issues would be unique, but apparently it’s not.

 

[ElectricIAC]

Ugh. Cell phones. “Resistive heating is a function”

dropping from 48a to 34a should cut the heat in half.

Before we replaced our breaker, we had this same issue. Backing off our Gen1 UMC/14-50 down to 26-34A kept it happy.
Didn't have that issue in winter but i'm sure summer heat wasn't kind to the hardware which trashed the breaker. Back at a happy 40A now and looking into a separate 125A service for our garage to have two HPWC.

 

[brkaus]

I did have to replace a breaker once. The initial install wouldn't work well - tripped down after an hour. Investigation found buzzing and heat in the breaker (brand new). Replaced it and has been fine since.

 

[mike123abc]

I had a similar issue, but it turned out to be the charging pin inside the car charging port. Check to be sure the pins all look OK. There was a TSB on the plastic covers of the pins breaking off. They could get stuck in the wall plug so it would not insert all the way in, or by breaking off the plug would not fit in tight causing issues. They replaced the pins in my plug.

 

[eddieb3]

UPDATE: Got the Torx security drill bit from Amazon today, so was finally able to open up the wall connector to see if I could find anything that looked wrong. Yikes! The insulation around the main black wire is flaking right off and showing some bare wire. Heat, I'm sure, caused this. If you touch it, the insulation is very brittle and just crumbles and falls right off. See three attached pictures.

Question is why? I'm going to call my electrician. And maybe Tesla. In the meantime, I've closed it back up and left the breaker off. It will be the Supercharger, which I've never used in the two years I've owned the car, until this gets figured out and fixed. Glad I caught this before anything serious happened.

Any insights or suggestions are encouraged. I will update further as I know more.

 

[brkaus]

@eddieb3 Wow. Good find!

• The wire wasn’t tightened enough, or
• A few strands didn’t make it in the connector (like the sloppiness on the ground), or
• The wire was t stripped to the proper depth and fully inserted, or
• A few strands broke, or
• The wire is undersized, or
• The connector is bad.

That’s scary.

edit: is that aluminum wiring? I doubt it, but the color is a bit strange.

 

[eddieb3]

@eddieb3 Wow. Good find!

• The wire wasn’t tightened enough, or
• A few strands didn’t make it in the connector (like the sloppiness on the ground), or
• The wire was t stripped to the proper depth and fully inserted, or
• A few strands broke, or
• The wire is undersized, or
• The connector is bad.

That’s scary.

edit: is that aluminum wiring? I doubt it, but the color is a bit strange.

It's not aluminum. It's copper.

 

[AxlxA]

Who installed it? Maybe that person has some warranty to repair it.

All they're gonna do is cut that wire, pull it a little more and strip it again and reattach to the terminal. Sloppy yes.

I'm assuming the orignal install used the correct gauge, with the correct breaker, and the correct setting on the HPWC.

 

[MGES]

@brkaus Your troubleshoot ideas are on point. I am the one who installed this charger.

• You are correct that the lug might not have been tight enough. or the lug could have been too tight.
• I will definitely look to see if it was inserted correctly.
  
• the lug that the wire goes into has a stop at the top so it cant get pushed through. plus, you should never have exposed live wire protruding past the plastic insulation of lug casing. This I will also check as well.
• it is evident from the picture that no strands broke
• Remember, when installing any electrical system, all wire must be rated for more than the allowable ampacity of the disconnecting means. In this case the wire is a #6awg rated 65A. Even thought the insulation rating is 90C, we use the ampacity rated for 75C as a failsafe. this #6 is thus rated for 65A. The maximum current the breaker could produce is 50A. The wire is not undersized. So I will be checking to make sure the breaker trips properly.
• loose connectors (assuming lugs) will cause pit marks. I will open it up and see if there is any.

Note: Regarding the ground strand. you are correct, that one strand should be up further. notice tho it is still in the lug. But not a excuse, this will be fixed.
Regarding the interior of the charger. it seems to be coated in a fine brown dust. if your thinking rust, copper conductors don't rust, they corrode. Moisture causes cooper to turn green. Heat will break down insulation and start to darken the copper.

@AxixA

• You are correct, I will warranty my installation.
• It isn't sloppy to remove damaged conductor section. as long as all traces of corrosion or heat damage is removed. this is not sloppy. will i pull it and trim? we will see. However, I am not afraid to re pull the wire and install a new one free of charge.
• you are correct on all three conditions, the gauge, breaker and setting is all correct.

Final Note:
I am glad that I was informed about this problem. I plan on going tomorrow and fixing it. I will update this thread after the fix to show what the issue was and how I rectified it. I think that information like this is beneficial for everyone, even if it was my mistake i will own it and make it right.

Mike

 

[brkaus]

@MGES glad you’re on top of it! It’s a very difficult design to work with. I think I’ll open mine and have a look now that it’s been used a few years. I did put it in a 50a circuit so 40a is max load.

if you happen to be able to put ferrules on the wire that would also help.

 

[jdr93]

that deterioration looks like the wire manufacturer cheaped out and used the incorrect insulation. though the pictures don't show everything, the install looks professional and well done.