My HPWC almost melted down!!!

[FlasherZ]

Let's keep this //on topic. Start a new thread for ir prices and don't hijack this one.

If the internal wires were 6 AWG and 12" long, then the heating at 80A would only be 2.6 Watts. That's not sufficient to raise the temperature to 210F.

And we've already concluded there was a high-resistance junction creating the temperature increase. The HPWC was replaced and Tesla is analyzing it. It seems the topic has moved on?

 

[kennybobby]

The original unit was reading >400F and was replaced. The new unit is now reading ~210F and is being used in his garage. How many cycles before the temp goes up again? Guess it's not a problem if it's not in your garage?

 

[FlasherZ]

The original unit was reading >400F and was replaced. The new unit is now reading ~210F and is being used in his garage. How many cycles before the temp goes up again? Guess it's not a problem if it's not in your garage?

How many cycles? Perhaps hundreds, perhaps thousands, perhaps never... my HPWC has been working at 80A for over 2 years and the only issue has been dirty contacts at the car's end. This is the first report of its kind here, and there are hundreds of members with HPWC's - one would think if it were too high, we'd hear more reports of the internals nearly melting.

With that said, the internal wiring heat dissipation is not going to be anywhere near the primary heating factor involved. Any junction (including the crimp) is going to have some resistance, the electronics and fuses will generate some heat along with the contactors, and even some of the heat generated along the entire length of the cable can be conducted back into the unit with the rubber of the cord acting as a heat insulator. The sealed cabinet of the HPWC will allow it to build.

Is 210 deg F too high for 80A over that junction generated from 3 hours of charging? I don't know... the wire is rated at 105 deg C, so it's still within spec. We don't even know how well-calibrated the device that was measuring it was, either.

 

[EchoDelta]

I don't think it's within the range of adding value, ... but do others think liquid cooled HPWCs are worth it?

 

[FlasherZ]

I don't think it's within the range of adding value, ... but do others think liquid cooled HPWCs are worth it?

I think the complexity of such an HPWC wouldn't be worth the trade-offs (pumps, fluid levels, etc.). If I were Tesla, I'd increase the size of the unit and wires before I would go that direction.

 

[wk057]

I think the complexity of such an HPWC wouldn't be worth the trade-offs (pumps, fluid levels, etc.). If I were Tesla, I'd increase the size of the unit and wires before I would go that direction.

^this. Seems like it would be a piece of cake to simply bump the gauge of some of the wiring and reduce resistance there. Perhaps a more heavy duty contactor as well. Could probably be done inside the same casing.

 

[jerry33]

I think the complexity of such an HPWC wouldn't be worth the trade-offs (pumps, fluid levels, etc.). If I were Tesla, I'd increase the size of the unit and wires before I would go that direction.

Agreed. The downside to liquid cooling is that it will require some maintenance down the road, and it's not likely to get done.

 

[Atebit]

Convection louvers even?

 

[AmpedRealtor]

Convection louvers even?

Heat is generated along the entire current path, including the black cable. Convection louvers or a heat sink will only mitigate the effect at that particular location, but more heat will be generated downstream regardless. In my case, the cable and nozzle are HOT here in the summer. So hot that service suggests dialing down the current in the summer time. Since heat is additive, the HPWC is almost untouchable when it's over 110 degrees outside.