PMCC - Overheated

[Dweezel1]

this is outstanding information - and if true I agree if UL labs does not rate the cord for 40 amps continuous that would be a safety issue - posting that information here however does no good.

have you contact Porsche North America about your findings and provided the documentation from UL labs.

we’ve always known 10 gauge wire is a bit iffy for 40 amps continuous load - I’d like to see Porsche/Audi/VW update teh cord to 8 gauge wire for their EV fleet - it’s really really substandard.

I have confirmed the 30 Amp rating as to cord component (not plugs) through UL.

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[Dweezel1]

Some light reading for you: https://www.taycanforum.com/forum/threads/nema-14-50-supply-cable-heat-data.1940/

TLDR: The 10 AWG cord is not optimal at 40A, but it is electrically safe.

I would not bank on that. The rubber on my cable partially melted and the copper delaminated. The core temp at the metal of the plug may indeed be way higher than these spot measurements of the rubber.

 

[Dweezel1]

The attached is UL information. The plug can be manufactured with wire if 6 gauge/8 gauge/10 gauge.

The 10 gauge Porsche plug/wire combination is approved for 30 Amps.

 

[smohr33]

I sympathize with your concern and applaud you for taking this up with PCNA. Will check my 6-50 cord for you tonight to see what AWG it is, I assume it's 10 also.

I have a decent knowledge of UL files and standards via my career, albeit a completely different industry.

I went into the UL product database and do not see Porsche or VW listed with any files. PMCC appears to be a bunch of components that are recognized and listed independently, I can't find a file for the completed assembly via a quick search.

Tesla lists their file E351001 for their wall charger right in the manual, and I'm able to see it in the database. UL category FFVI2. There are only 85 files under FFVI2, some of which are to German companies. PMCC could be made by one of them.

 

[chrisk]

I bet Porsche will give you a new cable (gauge 10) and they will tell you to lower amperage to 30A. If you push them they might reimburse your PMCC and/or buy it back. But I doubt they will address the actual problem. Good luck and let us know how it goes.
I charge at 25A just to be safe even though my setup supports more.

 

[Dweezel1]

I sympathize with your concern and applaud you for taking this up with PCNA. Will check my 6-50 cord for you tonight to see what AWG it is, I assume it's 10 also.

I have a decent knowledge of UL files and standards via my career, albeit a completely different industry.

I went into the UL product database and do not see Porsche or VW listed with any files. PMCC appears to be a bunch of components that are recognized and listed independently, I can't find a file for the completed assembly via a quick search.

Tesla lists their file E351001 for their wall charger right in the manual, and I'm able to see it in the database. UL category FFVI2. There are only 85 files under FFVI2, some of which are to German companies. PMCC could be made by one of them.

Thanks. The UL numbers (plug is one number, other side plug another, cord all different UL numbers). They are all in UL database directly.

I think pigtail is custom made from these three components, as origin countries different, and end that goes to unit proprietary.

I agree with other poster they will replace my cord, tell me to dial down, and not address the real issue. I would (un)happily get a real charger at that point but do think they need to address this issue correctly.

Porsche makes great cars. The company is sometimes not responsive enough IMO.

 

[smohr33]

Confirmed the 6-50 pigtail is 10AWG, as is the 25ft cable.

Also noticed that the J1772 connector is rated 250V/41A.

 

[Dweezel1]

Confirmed the 6-50 pigtail is 10AWG, as is the 25ft cable.

Also noticed that the J1772 connector is rated 250V/41A.

I am guessi

Confirmed the 6-50 pigtail is 10AWG, as is the 25ft cable.

Also noticed that the J1772 connector is rated 250V/41A.

Thanks. This is so confusing though. I don’t have an amp meter. If they are both 10 AWG and the run to the car is obviously much longer than the pigtail, why wouldn’t the long wire be even hotter than the short wire?

I am not an expert in this. Is the current in pigtail 40 Amps AC and being converted to DC after the module so load on long wire not as high?

 

[Jhenson29]

I am not an expert in this. Is the current in pigtail 40 Amps AC and being converted to DC after the module so load on long wire not as high?

No. It’s AC all of the way to the car. Current in the vehicle cable should be fairly close to current in the supply cable. Supply cable will be negligibly higher due to powering PMCC.

I don’t have an amp meter.

Unless you’re cutting the cable apart, you’re not going to measure the current. You’d have to go around a single conductor, not the whole cable.

 

[chrisk]

My PMCC's 14-50 supply cable is also #10 size but it has a big sticker that says 16A output...
Do you also have the same label attached to the input cable?

 

[Dweezel1]

My PMCC's 14-50 supply cable is also #10 size but it has a big sticker that says 16A output...
Do you also have the same label attached to the input cable?

Yes. I removed mine but exactly same.

 

[Jhenson29]

Additional reading:
https://static.nhtsa.gov/odi/tsbs/2020/MC-10179275-0001.pdf

The Porsche Mobile Charger and Porsche Mobile Charger Connect are certified with all applicable cables to UL 2594 standards

Anyone have a copy of UL 2594 for reference?

 

[NC_Taycan]

There is a TSB confirming that the label showing 16A is wrong. The adapter is fine (at least as fine as 10 AWG wire is for 40A continuous)...

 

[Jhenson29]

The adapter is fine (at least as fine as 10 AWG wire is for 40A continuous)...

…is it though?

From a practical standpoint, if it were fine, the forum wouldn’t be littered with complaints. I’m guessing this is going to be an annual thread…

But additionally, NEC 625.17 says the supply cable has to have an ampacity from Table 400.5(A)(1), which would be 30 amps for 10AWG SRDT with 2 current carrying conductors. Edit: 8AWG looks like it would be sufficient. It’s not based on Table 400.5(A)(1), but, per 625.17, 8AWG and larger appears to be able to use Table 400.5(A)(2), which is higher.

The 12” limit on supply cable length also appears to come from 625.17 and 625.22, both referencing a maximum distance from the plug to the personal protective system.

 

[Dweezel1]

…is it though?

From a practical standpoint, if it were fine, the forum wouldn’t be littered with complaints. I’m guessing this is going to be an annual thread…

But additionally, NEC 625.17 says the supply cable has to have an ampacity from Table 400.5(A)(1), which would be 30 amps for 10AWG SRDT with 2 current carrying conductors. Edit: 8AWG looks like it would be sufficient. It’s not based on Table 400.5(A)(1), but, per 625.17, 8AWG and larger appears to be able to use Table 400.5(A)(2), which is higher.

The 12” limit on supply cable length also appears to come from 625.17 and 625.22, both referencing a maximum distance from the plug to the personal protective system.

Thanks for posting that.

I am not a rocket scientist but in my case at 40A the heat melted the rubber plug, and has frequent shut offs and warnings. The pigtail adapter is measured hot enough to burn you. My circuit to breaker is 20 feet and 6 gauge wire on a 50 Amp breaker.

As other poster said, the thread shows this is not isolated issue. Simply put something is wrong and Porsche can say anything they want, it is still an issue.

I also noticed the Porsche dealer I go to their charger is only delivering 3.3 KW and in addition they stated they did not even have a 50 Amp 240v NEMA receptacle to test the mobile charger.

Dialing down 32 Amps has solved the issue in my case in terms of the heat. Does not trigger warning and temperature warm on readings but not excessive.

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