I have had a Tesla HPWC for the past year and charge daily. Woke up this morning and smelled something odd in the garage it didn't neccesarily smell like something burning, but it smelled like a weird plastic odor. Did some digging around and opened her up a found this. Wires are getting fried. Something in the back of my mind said to immediately check the charger even though I have other electrical components in the garage the charger was my first gut feeling.Just a fyi to people always be careful and investigate stuff out of the norm.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
HPWC issue
- Thread starter Dypkny845
- Start date
Ostrichsak
Well-Known Member
Who installed it? What size wire & circuit was used on the circuit? What amperage are you drawing at for charges. I'd be curious to see how the wires were landed too.
Yeah, I'm not too familiar with what the interior connection points look like inside a wall connector, so is that wire coming in the top your input line? If so, then I agree that it does look like aluminum, which is not allowed.
Ostrichsak
Well-Known Member
This goes back to my original response that I wanted to see how the wires were landed. If there was ANY amount of insulator present or if the lugs weren't properly tightened down this could create some resistance at the lug which would generate heat. Over time this can slowly make matters worse. If I had to guess, this is the cause. You can use aluminum wire as long as it's the proper size (read: much larger than copper) for the circuit although it's not advisable due to the temperature swings that can cause the aluminum to expand/contract a little more than the copper wire. They often use aluminum to supply main panels because these longer runs are more expensive and your main panel never really cycles to 80% and then 0% the way these HPWCs do regularly. This constant 80% to 0% (and occasionally in between somewhere) can cause issues with contraction and expansion. So aluminum isn't advisable for this application and you could be experiencing why. This would manifest itself in a situation where you may have tightened the lug properly but over time of expansion and contraction it managed to work itself ever-so-slightly loose resulting in increased resistance. As we all know, added resistance in electricity equals heat which is bad.
Thanks for the info!!...now when you say how the wires were landed you mean the Main House Wire to the Main Panel? if so then that is def copper.
Last edited:
Ostrichsak
Well-Known Member
No, as in how you connected the wires to the lugs of the HPWC itself. This is where the symptoms are present so this is likely where the problem exists.
I want to clarify this some. It is allowable to use aluminum wire for some things only if the lug connection points at the ends are made and rated to accept either copper or aluminum. In this case, the wall connector manual says that it is not rated for aluminum, so for the final attachment there, it does have to be copper wiring.
But for some people's installations that have a very long wiring run from a main panel to a garage, yes, it would be a good cost effective idea to do the main length of the run in aluminum wiring to a sub-panel in the garage that has copper/aluminum rated lugs. Then from there, you can do the shorter connection in copper to the wall connector.
I had a similar issue with my HPWC, except it was the internal terminals in the main body, not in the top entry bracket. And my installation was using 6AWG on a 60A circuit (which BTW is code-compliant here in Ontario, before some NEC-expert points this out) In my case there had been a small sliver of insulation captured by one terminal, which of course resulted in a poor metallic connection, resulting in contact heating and eventually charring the insulation on one wire only, which I noticed due to decreased charging voltage at full load compared to no load. I don't believe the Tesla HPWC terminals are the best connection hardware. I would much prefer normal circular lugs with beefy set screws to be able to apply more torque.
Ostrichsak
Well-Known Member
That's an important distinction and one worth pointing out as I by no means want to advise anyone do something dangerous. I believe (and I could be wrong here too) that this could be a change for the Gen 2 HPWC that's been out for a bit now. I'm not 100% but I believe it was an option on the Gen 1 HPWC and I believe that's where I read it. I don't recall where I read that but I wasn't planning to do it either way so this is why I don't recall the specifics.
For me it doesn't much matter anyway because I would only run copper wire for these HPWC given the nature of how they work. Having something run 80A continuous and then dropping to 0A for prolonged periods is a fairly tall ask especially when your wire is just barely meeting minimums. As stated previously, the byproduct of resistance is heat and aluminum will expand more than copper and this is why I wouldn't run aluminum for an application such as HPWC even if the installation instructions said it was possible.
Similar threads
