PMCC - Overheated

[daveo4EV]

Thx - sort of figured as much but def layman expertise level here - was speculating in my head that there might be potential for added resistance with #6 wire and if that might in some way effect the PMCC but clearly not the case- good. I'll advise my installer accordingly,
Cheers, C.

actually decreasing wire gauge number (increasing thickness) actually makes it run cooler and easier - more wire give the electron's more elbow room for a given current glow - so it will actually improve things for a given/fixed current/amps…

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[Jhenson29]

was speculating in my head that there might be potential for added resistance with #6 wire

vs…what?

Heavier gauge wire = less resistance.

 

[ciaranob]

vs…what?

Larger gauge wire = less resistance.

Again layman knowledge! My warped thought process was in case the PMCC unit was spec'd for thinner wire/specific load that it's cicuirtry might react badly to more efficient load sent its way i.e. was thinking more resistance at the unit to the feed, not specifically in respect the wire itself - but clearly again non-expert thinking and in reading back my own text not terribly logical either! Question answered regardless

 

[Jhenson29]

Again layman knowledge! My warped thought process was in case the PMCC unit was spec'd for thinner wire/specific load that it's cicuirtry might react badly to more efficient load sent its way i.e. was thinking more resistance at the unit to the feed, not specifically in respect the wire itself - but clearly again non-expert thinking and in reading back my own text not terribly logical either! Question answered regardless

No worries. I was just wanting to clarify. 6AWG will be fine. That’s what I used last weekend to wire up a 14-50.

 

[chrisk]

The only problem with thinker wire is that it is more expensive and harder to work with.. Even #6 is inflexible and not that easy to run inside conduits, flex inside an electrical box or connect to the breaker and 14-50 terminals. But I guess that is the electrician's problem

 

[Scotty]

So I finally got a chance to really test the PMCC last night. Car was @ 19% and set to stop at 85%. Plugged it in around 4:45pm and immediately saw the car go to about 9.3kW charging. Checked on the car around 8pm....and noticed it had dropped to 2.1kW. Thought this was odd....but maybe its part of the "optimization" setting since I don't care when it its done. Went into garage around 10pm and noticed the PMCC had a red screen saying it was too hot / limited service. See attached pic. The charger, the enclosure (dock) and the wire to the car.....were HOT. didn't take temps...but almost too hot for me to touch for longer than couple of seconds.

I know my electrical is good. Was installed with correct wire gauge, bends, junction, and circuit. The circuit itself was warm...but not hot and nothing out of the ordinary. But the PMCC...ws cooking itself. Garage was 90 degrees (thanks FL)....but one would think Porsche would have taken this into consideration. I have fully charged the car with a 3rd party unit (Mustart) and it had ZERO issues. Warm...but nothing out of the ordinary. Pulled a steady 38.9 amps from plug...and delivered 9.1kW to car without issues.

Anyone else seen this?

I live in Los Angeles, my charger is located outside on the side of my house. I have charged my car when outside temp over 90 degrees and no issues

 

[chrisk]

In case you are curious how the wires sizes compare here are couple of photos from leftover wires I have in my garage. They are all stranded wires (not solid) to compare apples to apples. From left to right
- 12AWG typically used for the household outlets
- 10AWG typically used for dryer or AC circuits with 30A breaker
- 6AWG typically used for NEMA 14-50 or 6-50

You can see that #6 is significantly thicker. And you need 3 wires like this (two hots + one ground) for a 6-50 or 4 (two hots + one neural + one ground) for 14-50.

 

[daveo4EV]

 

[Kingske]

In case you are curious how the wires sizes compare here are couple of photos from leftover wires I have in my garage. They are all stranded wires (not solid) to compare apples to apples. From left to right
- 12AWG typically used for the household outlets
- 10AWG typically used for dryer or AC circuits with 30A breaker
- 6AWG typically used for NEMA 14-50 or 6-50

You can see that #6 is significantly thicker. And you need 3 wires like this (two hots + one ground) for a 6-50 or 4 (two hots + one neural + one ground) for 14-50.

I believe the neutral is not being used by the PMCC. However, if you are running wire to a NEMA 14-50 you may as well do it properly and run four wires.

 

[ciaranob]

In case you are curious how the wires sizes compare here are couple of photos from leftover wires I have in my garage. They are all stranded wires (not solid) to compare apples to apples. From left to right
- 12AWG typically used for the household outlets
- 10AWG typically used for dryer or AC circuits with 30A breaker
- 6AWG typically used for NEMA 14-50 or 6-50

You can see that #6 is significantly thicker. And you need 3 wires like this (two hots + one ground) for a 6-50 or 4 (two hots + one neural + one ground) for 14-50.

in my case the exterior conduit is literally a straight horizontal distance of 10’ from sub-panel to where it will enter the back of the garage for sockets, so minimal issues re routing.

ps: forgot to mention my installer already had 6” in his quote - bit embarrassed that I missed that!

 

[Jhenson29]

I finally have the PMC+ up and running. I’ve been charging for an hour at 40amps (8.9kW at the car) and I haven’t been able to create any heat issues. It’s 92F ambient in my garage and the PMC+ supply cable is around 120F. About the same as other components and similar to my other 18kW EVSE. I don’t have a dock, but was still expecting higher temps.

 

[Dweezel1]

I finally have the PMC+ up and running. I’ve been charging for an hour at 40amps (8.9kW at the car) and I haven’t been able to create any heat issues. It’s 92F ambient in my garage and the PMC+ supply cable is around 120F. About the same as other components and similar to my other 18kW EVSE. I don’t have a dock, but was still expecting higher temps.

Remains a little bit of mystery overall. The unventilated charging dock appears to be part of equation for problem. Ambient temperature appears to be a part. 10 AWG 30 Amp rated pigtail seems part.

Many have undeniable issues. But not everyone. My rubber plug melting is certainly real and real problem. As well as many persons temperature measurement.

 

[XLR82XS]

Remains a little bit of mystery overall. The unventilated charging dock appears to be part of equation for problem. Ambient temperature appears to be a part. 10 AWG 30 Amp rated pigtail seems part.

Many have undeniable issues. But not everyone. My rubber plug melting is certainly real and real problem. As well as many persons temperature measurement.

I agree and wouldn't spend the $ on the dock/case - especially in hot climates. I live in S. Florida and don't have overheat issues. It's mounted low on garage wall between the doors (air flow) and no direct sun exposure. Night time charging is also not a problem with doors closed.

 

[Jhenson29]

Remains a little bit of mystery overall. The unventilated charging dock appears to be part of equation for problem. Ambient temperature appears to be a part. 10 AWG 30 Amp rated pigtail seems part.

Many have undeniable issues. But not everyone. My rubber plug melting is certainly real and real problem. As well as many persons temperature measurement.

For sure. I wasn’t posting to say there no problems in general. Just sharing what I found. I agree with all of your points.

 

[Chedman13]

I finally got my Taycan today! It's a brand new 2020 leftover. I have two PMCC's and wanted to share what I've found out on the plugs for the standard outlet and 14-50.

The old (2020) PMCC came with wall plugs that appear to be 2 feet in length (the newer PMCC comes with 1 foot cords) for both standard and 14-50 plugs.

The old also comes with a safety rating of 16A for both cords. The newer one of the 14-50 states 15A/24A/40A.

I assume my tech checked my 2020 PMCC and cords for recalls as he did check my newer PMCC (asked me to also bring in cords).

Either way, I'm using only the shorter, newer cords that are 1 foot in length as they are exactly the right length to the plug inside the Porsche Charging Docking Station/Cabinet.

Question - the standard wall outlet plugged PMCC gives me 6A to 8A options. I've selected 6A to be safe - any thoughts?

The 14-50 PMCC is set to 25A as someone else suggested to keep heat down, where 30A would be the maximum the cord is potentially rated for. I'd scaled it down further to 25A to be safe.

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