Terminal block melted on HPWC Gen 2

[GEAUXHOOKEM]

I love my Model X, but I'm starting to grow tired of little issues that I never experienced with ICE vehicles in the fist year of ownership. Last night my app popped up a message that stated the charging was interrupted. I immediately went outside to find that the vehicle had stopped charging and showed "Charge Cable Fault" and "No wall Power" messages on the digital dash. I can't tell you the particular light sequence on the charge port or the HPWC, but red was prevalent. I unhooked the charge head and placed it back in the HPWC receptacle. I reset the wall charger and hooked it back up to the vehicle. The vehicle wouldn't get pass 60 amps and then dropped to 30. I reset again. The charging sequence got up to the normal 72 amps and I went in the house thinking everything was good. A few seconds later I heard a pop in the garage. I went out to find the HPWC was dead. I checked the breakers which seemed fine and got around to popping the cover on the HPWC to find that a terminal block had melted. This charger has been installed since January and was done by a Tesla approved electrician. I've always charged at 72 amps without issue with voltage typically being in the 235-240 range. Maybe I just got a unit that bit the dust early, but I have to be honest when I say I'm tired of issues like this. It's not the end of the world, but it surely does change the family routine this week with the kids as we look to utilize Superchargers until this is remedied.

 

[AudubonB]

Ouch. From experience, my first reaction is: "Oops. Someone forgot to torque to the proper number".
But it could be any one of a number of other reasons.

 

[GEAUXHOOKEM]

Ouch. From experience, my first reaction is: "Oops. Someone forgot to torque to the proper number".
But it could be any one of a number of other reasons.

It's a pain for sure, but I always say things could be worse. In the grand scheme it is an inconvenience, exacerbated by the holiday season and everything that comes along with that. Tesla is supposed to be sending a mobile service technician out to evaluate the problem. The last time a ranger came out it took over a week before I was contacted to schedule an appointment. It was then another week before I could get on the schedule. I'm sure the individual will come out and say, yep, this needs to be replaced under warranty. They will then need to ship me a new unit and I will have to schedule an install with an electrician thus relegating me to superchargers until the years end. That isn't a big deal to most people, but adds another layer of responsibilities to my plate every other day to make sure the vehicles stays charged for use. It is what it is.

 

[JohnSnowNW]

A couple questions:

Can you not limp along on a regular wall outlet? I know it's slow, but typically our vehicles are sitting for around 10-12hrs at a time overnight.

Secondly, is there a reason you need to charge at 72A everyday? I realize you SHOULD be able to use that functionality with the HPWC purchase, but do you really need to? We have 14-50 outlets in the garage, 3 of them, and charge our Model X at around 30A, and the Model 3 at 20A. These rates are more than adequate to handle our daily driving, and I just like the peace of mind of not taxing the wiring/outlets.

 

[SSedan]

On the high amperage charging while not applicable for the OP it is nice in cold climates for the battery warming, and because it allows more consistent charge finishing right before you leave.

I would have to agree with the poster who said first suspicion would be a loose connection.

 

[Sparrow]

I almost never charge my EVs at full power for just this reason. I can get away with less than half power, which is what I do. For me there is no reason to stress the wiring and HPWC until I actually need to do so which is almost never.

As an extra step of redundancy, when I had the HPWC installed I also had my electrician install a 14-50 in the same spot. With the 14-50, I could use my UMC to charge the car too.

 

[GEAUXHOOKEM]

A couple questions:

Can you not limp along on a regular wall outlet? I know it's slow, but typically our vehicles are sitting for around 10-12hrs at a time overnight.

Secondly, is there a reason you need to charge at 72A everyday? I realize you SHOULD be able to use that functionality with the HPWC purchase, but do you really need to? We have 14-50 outlets in the garage, 3 of them, and charge our Model X at around 30A, and the Model 3 at 20A. These rates are more than adequate to handle our daily driving, and I just like the peace of mind of not taxing the wiring/outlets.

Points well taken. I’m sure we should be able to limp along until this is resolved. We live in Dallas and there is a significant amount of driving for us between work and kids activities. This holiday period if very taxing from a driving standpoint as well due to the sheer number of activities. We have three cars, so I’m really just complaining for no reason. I love driving the X though and hate to be without it . We are getting 3 mph on our UMC now as it’s plugged into a traditional home outlet. It may behoove me to install a NEMA 14-50 in the garage as well for situations like this. To your second point, I could definitely stand to throttle down the amperage since 72 isn’t required. I’m one of those people who just thought, I’d like this thing to charge as fast as possible and I got the HPWC and electrical setup to accommodate the fastest charge possible. It isn’t needed though. It (amperage level) will defitineitly be lowered from this point forward!

 

[animorph]

Dang, my garage gas pump never had that problem!

It does sound like a connection at the terminal block was not torqued correctly.

 

[SSedan]

That looks to be the included jumper which is rated for the 80amps the older cars could pull so an argument can be made it was not maxxed out.

 

[GEAUXHOOKEM]

Update - The company I used to do my original install immediately came over this morning and replaced the HPWC with a brand new one. They indicated that it could have been a number of things that caused this to occur, but would use my case as a training opportunity for their technicians as a preventative measure against install related issues. They took pictures and documented the entire process from breaking down the old HPWC to installing the new one. I'm glad that there are companies that stand behind their work and product. All that to say, crisis averted, and thanks for the feedback all!

 

[SSedan]

Sounds like they think it could have been a loose connection too.

 

[jboy210]

Update - The company I used to do my original install immediately came over this morning and replaced the HPWC with a brand new one. They indicated that it could have been a number of things that caused this to occur, but would use my case as a training opportunity for their technicians as a preventative measure against install related issues. They took pictures and documented the entire process from breaking down the old HPWC to installing the new one. I'm glad that there are companies that stand behind their work and product. All that to say, crisis averted, and thanks for the feedback all!

Did they say exactly what went wrong? Just swapping it without know why it failed does not inspire confidence that the replacement will not also die.

 

[MorrisonHiker]

A couple questions:

Can you not limp along on a regular wall outlet? I know it's slow, but typically our vehicles are sitting for around 10-12hrs at a time overnight.

Secondly, is there a reason you need to charge at 72A everyday? I realize you SHOULD be able to use that functionality with the HPWC purchase, but do you really need to? We have 14-50 outlets in the garage, 3 of them, and charge our Model X at around 30A, and the Model 3 at 20A. These rates are more than adequate to handle our daily driving, and I just like the peace of mind of not taxing the wiring/outlets.

I agree! We recently had 3 load-balanced Wall Connectors installed. If they have a problem, we have 2 14-50 outlets. If those go out, we have a 6-20 outlet. If that fails, we have several 5-20 outlets. If those have a problem, we have 5-15 outlets. Of course if all of those outlets have problems then I think there's definitely a bigger problem elsewhere!

We currently have 64 amps available on the 3 WCs. We typically charge at 32 amps or less per car but can reach the full 64 amps if we have two or three cars charging at once. That's pretty rare.

 

[GEAUXHOOKEM]

Did they say exactly what went wrong? Just swapping it without know why it failed does not inspire confidence that the replacement will not also die.

I stood by while the gentleman took apart the old HPWC to inspect it. I wouldn't expect them to come out and say it was a loose connection caused by a torquing issue, but all signs pointed to that. The fact that the company had the head superintendent come out within an hour told me everything I needed to know. It could have just been a defective terminal block (unlikely), but any answer I would have been given would be unverifiable by me based upon my limited expertise in electrical installs. What I can say is that I've gained more knowledge than I had before and I'm always willing to extend grace to someone willing to do the right thing immediately. The stakes are high with this stuff though so I'm definitely concerned. I intend to get a independent electrician to review the install tomorrow.

 

[mswlogo]

Without knowing all the details that looks like the fault of the installer.

That is one of the lines the installer needs to connect from the extender block.

And I will say I had a very hard time getting those in "right". The cables from the extender block a just exactly long enough and if you don't route them exactly right, they won't reach to fully seat in. I had to take it apart like 3 times until I was confident they were seated in far enough.

I don't think it was a torqueing issue. That left one was not pushed in enough when he torqued it down. You can see the yellow band is a lot lower on the left one. You can also see there is NO slack in that cable. I don't know if that was touched since failure.

You are also completely blind into confirming you have seated it in far enough. There is no guide or peep hole to confirm you have enough meat before cranking it down. One crude confirmation is they should look roughly even. If not, one is in further than the other. You can't go in to far. In that regard I think it's a poor design for such a high current device. I was cursing POS the during that part of the install. But overall the unit seems very well made.

Tesla might step up and replace. It might not be expensive to repair. I'd be very nice because I think technically it was the installers fault. Installer makes that connection and is responsible for it. I'd not complain to the installer either because the unit is a bit frustrating in that one area.

 

[ajdelange]

As part of every installation one should run up the charging as high as the particular installation and OBC allow, let it charge for a few minutes, take the cover off (a third hand may be necessary to maintain the cover with the ribbon cable connected but not stressed) and take an IR picture. Potential problems like this one will be immediately apparent.

This is going to be tough for the other ends of these pigtails (or impossible) but they are much easier to insert at that end than at the other.

Every good electrician should have an IR camera as part of his kit.

The reduced displayed charging current should have been accompanied by a reduced voltage reading. These two together are and indication that something like what you experienced is happening. A good safety feature for the WC would be to have it open the contactor if line voltage drops more than, say 15%. That would protect from a problem like this and from brownouts (not that I think brownouts would effect the OBC).

 

[mspohr]

I love my Model X, but I'm starting to grow tired of little issues that I never experienced with ICE vehicles in the fist year of ownership. Last night my app popped up a message that stated the charging was interrupted. I immediately went outside to find that the vehicle had stopped charging and showed "Charge Cable Fault" and "No wall Power" messages on the digital dash. I can't tell you the particular light sequence on the charge port or the HPWC, but red was prevalent. I unhooked the charge head and placed it back in the HPWC receptacle. I reset the wall charger and hooked it back up to the vehicle. The vehicle wouldn't get pass 60 amps and then dropped to 30. I reset again. The charging sequence got up to the normal 72 amps and I went in the house thinking everything was good. A few seconds later I heard a pop in the garage. I went out to find the HPWC was dead. I checked the breakers which seemed fine and got around to popping the cover on the HPWC to find that a terminal block had melted. This charger has been installed since January and was done by a Tesla approved electrician. I've always charged at 72 amps without issue with voltage typically being in the 235-240 range. Maybe I just got a unit that bit the dust early, but I have to be honest when I say I'm tired of issues like this. It's not the end of the world, but it surely does change the family routine this week with the kids as we look to utilize Superchargers until this is remedied.

I understand that you are upset at this problem but it's not Tesla's fault. It's clear from the photos that the wires were not installed correctly. The was a bad connection to the terminal block (high resistance) which caused it to overheat, melt, etc.
Your installer is at fault.

 

[WVhybrid]

As part of every installation one should run up the charging as high as the particular installation and OBC allow, let it charge for a few minutes, take the cover off (a third hand may be necessary to maintain the cover with the ribbon cable connected but not stressed) and take an IR picture. Potential problems like this one will be immediately apparent.

This is going to be tough for the other ends of these pigtails (or impossible) but they are much easier to insert at that end than at the other.

Every good electrician should have an IR camera as part of his kit.

If you open that box with 240v powered on, be sure to wear required proper PPE, including a faceshield.. An arc flash fire would ruin your day.

 

[mspohr]

If you open that box with 240v powered on, be sure to wear required proper PPE, including a faceshield.. An arc flash fire would ruin your day.

Might be best to shut off the breaker before opening the HPWC.

 

[mongo]

I don't think it was a torqueing issue. That left one was not pushed in enough when he torqued it down. You can see the yellow band is a lot lower on the left one. You can also see there is NO slack in that cable. I don't know if that was touched since failure.

You are also completely blind into confirming you have seated it in far enough. There is no guide or peep hole to confirm you have enough meat before cranking it down. One crude confirmation is they should look roughly even.

May not have been torqued at all... Given the length difference between the red and black, it may only have been incidental spring contact (or gripping a strand or two on the end).

Isn't the yellow band itself a gauge? First, strip the insulation back the proper, measured, amount. Then, optionally, add a ferrule. Insert wire until insulation (or ferrule) contact the terminal block. Tighten to proper torque. Same setup as any outlet or breaker.

You can also gauge position by tightening the terminal without the wire. Then see check how far the wire will insert. Loosen the terminal and make sure the wire is a terminal depth further in before the final tightening.