HPWC Fried

[whitex]

@mhunt, Looking at the pictures closer, it looks like one strand was broken inside the insulation. The break, or a crack, caused a high resistance point, which caused that strand to heat up and melt out of the insulation. If that's it, it might have just been a production defect (or maybe someone tried cutting the wire and then changed their mind after just cutting into the insulation), which might have gotten worse as the wire was bent to run it during installation (AWG2 takes some force to bend). If that is the case, the HPWC might still be good, just a faulty wire. Of course, this is purely theoretical, based on internet pictures, so please check with qualified professional.

PS> if that copper strand touched the circuit board after melting out of the insulation, then it might have fried something.

 

[appleguru]

@mhunt, Looking at the pictures closer, it looks like one strand was broken inside the insulation. The break, or a crack, caused a high resistance point, which caused that strand to heat up and melt out of the insulation. If that's it, it might have just been a production defect (or maybe someone tried cutting the wire and then changed their mind after just cutting into the insulation), which might have gotten worse as the wire was bent to run it during installation (AWG2 takes some force to bend). If that is the case, the HPWC might still be good, just a faulty wire. Of course, this is purely theoretical, based on internet pictures, so please check with qualified professional.

PS> if that copper strand touched the circuit board after melting out of the insulation, then it might have fried something.

That L1/L2 terminal block is melted...

I would strongly recommend replacing the HPWC (and the wire that connects it).

 

[whitex]

That L1/L2 terminal block is melted...

I would strongly recommend replacing the HPWC (and the wire that connects it).

Yea, I think you are right (I missed the melted plastic on the terminal). While the terminal may be replaceable for few dollars, ranger will just recommend a new one because I dubt they recondition them.

 

[jeffro01]

At the risk of feeding your OCD, do you have a FLIR camera? Every now and then I walk around and check temperatures of things, checking for any unexpected hot or cold spots. I engage my HPWC at 80A to make sure nothing along the way (from breaker to car) heats more than than in the past. Just my geeky OCD, but FLIR saves me from having to take covers off to inspect (I have OCD combined with laziness ). Only once did I ever find something, a loose wire on one of my breakers (was heating up more than others, turned out it was not tightened properly), but like you, I don't mind checking from time to time.

Haven't invested in a FLIR camera just yet but maybe some day... LOL The way my HPWC is wired I have to open up a junction box in the middle of the run where there are aluminum splicers to extend the #2 copper and the FLIR wouldn't help me so since I have to take that cover off I figure what the hell... LOL In my installation it's the splicers I focus on most and only check them after the car has been charging at 72amps for 30 min or longer to get a proper gauge of heat buildup.

When/if we ever get a second Tesla I'll upgrade the aluminum splicers to #2 copper three way so I can branch off the 100amps from the panel to the individual HPWCs with the communication wire thingy... For now, the aluminum seems to be doing fine and I haven't seen any resistance issues at the splicers.

Jeff

 

[whitex]

Haven't invested in a FLIR camera just yet but maybe some day... LOL The way my HPWC is wired I have to open up a junction box in the middle of the run where there are aluminum splicers to extend the #2 copper and the FLIR wouldn't help me so since I have to take that cover off I figure what the hell... LOL

You don't always have to take covers off just to check if anything has changed thermally. If you notice things getting warmer, by all means, you want to take covers off to see what's the source. I have a FLIR version that hooks up to a phone, it's nice because it takes pictures and videos, plus it takes regular pictures and thermal ones, then overlays them, lets's you swipe between them so you know what you're looking for, get temp measurements by just clicking on the picture part, etc. Used it once to locate a flood source at my in-law's place too, they noticed water dripping from the ceiling light fixture, went home, grabbed the FLIR, it was very easy to see where the water is flowing above the ceiling and track the source (the water was cooling off parts of the ceiling on top of which it was flowing), which turned out of be a loosened drain pipe under a tub upstrairs.

When/if we ever get a second Tesla I'll upgrade the aluminum splicers to #2 copper three way so I can branch off the 100amps from the panel to the individual HPWCs with the communication wire thingy... For now, the aluminum seems to be doing fine and I haven't seen any resistance issues at the splicers.

Even my giant 100A HP rated safety disconnect switch uses aluminium contacts. No problems handing sustained 80A load (FLIR verified ). I also use aluminium bars to split the 100A cirtcuit to two HPWC's, no problems there either.

Example of what the FLIR overlayed image looks like (the hottest in this picture are the AFCI breakers, even without load they are hotter than the above breaker charging a car at 40A).

 

[ktarasov]

I have the same issue. The design here is very unfortunate, they installed a PCB terminal block that has very inconvenient clamps to begin with and it also points down and inward in a very cramped space where you have to work with thick wires. In my case one of the wires went under the clamp instead of into the clamp and unfortunately the way the connector is it was still possible for the wire to get pinched by the screw, so this worked for about 6 month slowly arcing. So now the question is how to purchase a replacement termination block. I found the manufacturer but they only sell in bulk. Anyone knows where to purchase this terminal block (three pole is depicted but that is configurable) . https://www.dinkle.com/en/terminal/outpagepdf.php?dpid=1035 or a block that would fit into this exact footprint?

 

[mvotb]

What a piss poor designed block, requiring a blind connection. Should have visible lugs with a plastic cover. I would think that the small wire is one strand that expanded out of the insulation from heat.

 

[ktarasov]

What a piss poor designed block, requiring a blind connection. Should have visible lugs with a plastic cover. I would think that the small wire is one strand that expanded out of the insulation from heat.

Possible hard to tell, I was able to resurrect this terminal block after cleaning all burnt plastic. It works well enough but yes the design is surprisingly error prone.

 

[murphyS90D]

Possible hard to tell, I was able to resurrect this terminal block after cleaning all burnt plastic. It works well enough but yes the design is surprisingly error prone.

Did you use copper ferrules on the ends of the copper wires like the installation instructions recommended? They make it imposible for there to be any stray strands of wire.

 

[mvotb]

Yes, I should have said that it might be able to be reused. If you haven't already installed it you might want to clean the lug with muriatic acid and a q tip a few times to clean the metal good, then baking soda to neutralize the acid, rinse good. If the lugs are only held by the plastic, I can see how it might be difficult to torque properly without breaking the plastic. I couldn't tell, but the screwheads didn't look conducive to a good torque either. I would re torque every few months for expansion and contraction, until 0 movement, and use ferrules. My apologies if you already knew these simple things.

 

[ktarasov]

Did you use copper ferrules on the ends of the copper wires like the installation instructions recommended? They make it imposible for there to be any stray strands of wire.

No I did not. I should have known better since it was difficult to get the wires in but it is just not common to use ferrules. Also I could not find a crimper or ferrules for wire size AWG #4. Anyone knows where to get one?

 

[murphyS90D]

I used 2 gauge wire because of a 75 foot run.

https://www.amazon.com/gp/product/B01I9ECUE2/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

https://www.amazon.com/IWISS-Non-In...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

 

[bishoppeak]

I used 2 gauge wire because of a 75 foot run.

https://www.amazon.com/gp/product/B01I9ECUE2/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

https://www.amazon.com/IWISS-Non-In...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

I did the same and ended up having to remove a couple strands from the wire ends and crimp the ferrules to get them to fit properly in the receptacle.

 

[ktarasov]

I used 2 gauge wire because of a 75 foot run.

https://www.amazon.com/gp/product/B01I9ECUE2/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

https://www.amazon.com/IWISS-Non-In...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

Thanks! Sounds like you installed 80amp line with 100amp circuit breaker. What size grounding wire did you use and what diameter conduit? Any overheating issues in the panel?

 

[murphyS90D]

Thanks! Sounds like you installed 80amp line with 100amp circuit breaker. What size grounding wire did you use and what diameter conduit? Any overheating issues in the panel?

I used a #8 ground wire (green) and three #2 wires (red, black, white) to a sub-panel in the garage. The conduit is 1-1/4" PVC and is located entirely inside of the house. All wire ends had copper ferrules crimped on. No temperature problems in the main panel, sub-panel, wires, or the HPWC. There is a 100 amp breaker in the main panel and another 100 amp breaker in the sub-panel that feeds the HPWC.