NEMA 14-50 Supply cable heat data

[wemct]

I had an electrician install a 50A breaker today as well as the 14-50R outlet for the Porsche Mobile Charger Connect. The electrician used 6 gauge wire from the panel to the outlet. When I plugged in the car, the PMCC started to charge at 39.7-39.9 amps. The supply cable DID NOT get hot even after an hour of charging. The temperature remained stable. I could hold the supply cable in my hand (warm). It was the about the same temperature as the 25 ft. charging cable. The 50A breaker was warm but not hot.

Sponsored

 

[wmras]

I had an electrician install a 50A breaker today as well as the 14-50R outlet for the Porsche Mobile Charger Connect. The electrician used 6 gauge wire from the panel to the outlet. When I plugged in the car, the PMCC started to charge at 39.7-39.9 amps. The supply cable DID NOT get hot even after an hour of charging. The temperature remained stable. I could hold the supply cable in my hand (warm). It was the about the same temperature as the 25 ft. charging cable. The 50A breaker was warm but not hot.

Great news! Nice installation.

Being in free air outside a dock enclosure may be a contributing factor (similar to what we will install).

When the power is off, please the embossed gauge of wire. Is it 10AWG?

Thanks.

 

[KenU]

Nice work there, wemct!

Today my electrician came and replaced my 6 gauge wire with a 4 gauge along with a new Hubbell (sp?) receptacle, per Bill’s recommendation. Electrician had to be somewhat creative with the receptacle’s box to ease getting the wire in to the receptacle. 50A breaker in the basement 70 ft away. My wife’s 4S is currently at 85% SoC. Haven’t driven the car as it was stuck in the garage while we dealt with a few days of not having power due to the storm here in NE last week. Power came back on over the weekend. Will charge back up soon and let you all know if this resolves the heat issues, for me anyway.

I’m hoping this revised set-up will cool things down a bit and have the same or close to what wemct has now achieved. If not, then I’m convinced the supplied 14-50 plug/cable is defective. See below. Caulking could’ve been neater but all-in -all not a bad installation.

Fingers (and toes) crossed....

 

[KenU]

This was my original set-up.

 

[wemct]

Great news! Nice installation.

Being in free air outside a dock enclosure may be a contributing factor (similar to what we will install).

When the power is off, please the embossed gauge of wire. Is it 10AWG?

Thanks.

Yes my 14-50 supply cable is the 10AWG/105C rated cable.

 

[Toby Pennycuff]

A response I received this morning from my dealer regarding this issue. I have an open and acknowledged PRMS issue with PCNA regarding this heating issue with the PMCC.......

"The response we received from Porsche is as follows.

They are aware of the cables heating up during charging and are looking into it with PAG. They said that the cords are certified as an assembly with the chargers however they understand the concern of the cable getting quite warm. They suggested turning the charger current down to 30 amps to help with the cable heating up." (NOTE: the emphasis is mine.)

Well, we all knew that Porsche was going to fall back on their assertion that the cable is "certified". Once again, the accountants are in control! Shades of Dr. Wedieking all over again!

I would really like for the internal Product Manager who suggested that he/she "...understand(s) the concern of the cable getting quite warm" to come over to my house and hold that cable/plug in their hand for even 30 seconds. The good news is that a hospital is not far away so they could get treatment for the second-degree burns they will receive.

And please do not get me started on the recommendation to reduce to a 30Amp charge rate. We are back to the e-Hybrid charging rates of 7.2kW! I have to believe that Porsche simply took the power whip for the PMC (rated at 7.2kW/32 Amps), slapped a new part number on it and shipped it with the car. How else would one describe/explain what has happened?

SIGH

Toby

 

[Toby Pennycuff]

Great news! Nice installation.

Being in free air outside a dock enclosure may be a contributing factor (similar to what we will install).

When the power is off, please the embossed gauge of wire. Is it 10AWG?

Thanks.

Agree that your electrician did a nice job. I have a similar setup at my Dallas house, while I simply have the PMCC mounted on its included mounts here at my weekend house.

I wish I could offer up that being in the free air outside of the Porsche dock would help mitigate these extreme temps, but that is not the case for me. In both installations, I am experiencing excessive heat on the power whip.

And yes, my installations were performed by a commercial electrician who took exactly ZERO shortcuts on the wiring or components used.

Toby

 

[daveo4EV]

Dear Porsche,

thank you for your kind response and acknowledgement of the PMCC cable overheating issue. The response that I should turn down my 40 amp charger to 30 amps will mitigate the problem but does not address the specified feature of a 40 amp charge rate as documented in many different places by Porsche. Please advise as to the return and refund policy for my Porsche Mobile Charge Connect as it does not meet the specifications as outlined at the time I ordered the 40 amp charge rate product.

Also given that you have acknowledged a problem with utilizing the Porsche Mobile Charger Connect at it’s fully rated 40 amp level, what 40 amp charger does Porsche recommend at this time to achieve the documented 9.6 kW charge rate promised in the Taycan specifications.

I look forward to returning my $1270 PMCC and $470 PMCC Dock enclosure and will consider instead purchasing a $399 40 amp ChargePoint J-1772 EVSE that does not overheat during normal use at 40 amps.

I’ll look forward to instructions for a return and refund policy for the PMCC and related PMCC dock. I equally look forward to Porsche’s recommendation for a high quality Taycan charger that can achieve the documented 40 amp 9.6 kW charging level. My neighbor has a Tesla and I have been hearing good things about the quality and reliability of the Tesla EV charging products, would Porsche recommend using a Tesla Wall Charger with my Taycan? My neighbors charger has worked for years and suffers no overheating problems.

I look forward to Porsche’s response to this deeply concerning short fall in expectations for a premium product.

Sincerely those who believed Porsche would do better than an expected marketing response to a ground breaking flag ship EV product.

NOTE; for future reference the correct response should have been - points deducted from house Porsche for trying to behave like a company that doesn’t care.

Dear Porsche customer - we have discovered a potential issue where in some cases the provided NEMA 14-50 & 6-50 PMCC supply cables can reach warmer than expected temperatures. While this cable is certified for use at 240 volts & 40 amps we recognize the thermal levels that the cable sometimes reaches does not meet customer expectations for a mobile Porsche product. At this time we recommend customers adjust their charging level to 32 amps or less (see instructions here) - and we will be providing replacement PMCC supply cables at the earliest opportunity free of charge to address the rare but potential thermal issues for some 40 amp use cases. We deeply regret this oversight and know that it has failed to meet your appropriate expectations as a loyal Porsche customer. In exchange for your understand we are enclosing a gift certificate good for one base Model 911 or Macan, please work with your dealer to redeem the certificate for a future production slot no later than Dec. 31, 2021 - all options, registrations, taxes and delivery fees with be the customers responsibility but the base model vehicle cost is on us because we screwed up trying to save $7.69 by shipping a 10 gauge cable instead of the more correct/obvious choice of an 8 or 6 gauge cable like the rest of the EV industry. Again we regret this oversight in obvious EV 40 amp use case and hope the free cable and base model Porsche gift certificate make up for our oversight.

 

[daveo4EV]

@Toby Pennycuff - thanks for the update.

 

[HelfFL]

Well written @daveo4EV. In the meantime, I am looking forward to @KenU's results switching to 4 gauge wire and industrial receptacle. I am waiting for my Clipper Creek HCS-50p 40 amp charger to arrive to test that charging station and see if it will have a different result with my wiring and circuit breaker.

 

[daveo4EV]

I'm going to predict the 4 gauge wire will make little if any difference - the problem is NOT the feed (my supply cable data shows it running 87F) - the PMCC supply cable Porsche is providing is simply not up to the task - the solution is not different power supply cable from the breaker to the outlet - it's an appropriate wire gauge for 40 amp supply cable from the outlet to the PMCC.

I believe the following to be true:

1. 10 gauge wire is safe/rated/certfied for 40 amp usage - there is no electrical/safety issue here from a "wire will fail/melt" point of view
2. 10 gauge wire was a poor choice for a "mobile" solution where humans may touch the cable in normal use scenarios due to higher than comfortable to human touch temps under normal use.
3. 10 gauge wire can get uncomfortably hot after hours of use @ 9.6 kW
   1. this will be especially true if you use the "Mobile" charger in a "mobile" situation where the charger & supply cable may be subject to direct sunlight on a hot day
   2. can you say TrackDay w/PCA GGR or Diablo region @ Thunderhill @105F ambient air temperature in August/Sept - I knew you could!!
4. having 10 gauge wire in an enclosure with limited airflow (i.e. the Porsche Dock) will aggravate the thermal issues but still not be an electrical safety issue
5. the PMCC will have less thermal issues in an open air environment as there will be greater cooling available to the cable
   1. the cable in this case is "air cooled" like the original 911 - original Taycan owners will cry foul when at some point in the future Porsche moves to liquid cooled cables
   2. oh wait they already have move to liquid cooled cables - 350 kW @ 800 volts - the cables are liquid cooled -
6. Porsche should provide a replacement 14-50 & 6-50 supply cable with a lower gauge wire (6 or 8 gauge) - this will lower the temperature of the wire under normal use.
7. I won't hold my breath for #6 to happen - but would be unsurprised that in some future PMCC kit the 6-50/14-50 silently get a new part # and the only difference is the wire gauge…
8. when/if #7 happens Porsche will charge more for the new enhanced supply cable part than a full dual charger setup from ClipperCreek.

 

[Toby Pennycuff]

We deeply regret this oversight and know that it has failed to meet your appropriate expectations as a loyal Porsche customer. In exchange for your understand we are enclosing a gift certificate good for one base Model 911 or Macan

DAMMIT!I missed out on applying this (future) gift certificate against my Macan GTS purchase (literally one month after taking delivery of my Taycan!).

 

[daveo4EV]

@Toby Pennycuff the gift certificate is only good for a "base" model Macan - not a GTS model.

 

[Toby Pennycuff]

I look forward to returning my $1270 PMCC and $470 PMCC Dock enclosure and will consider instead purchasing a $399 40 amp ChargePoint J-1772 EVSE that does not overheat during normal use at 40 amps.

For accuracy purposes (for those of us who blindly seem to buy "stuff" from Porsche because it is conveniently labeled "PORSCHE" - and I have NO IDEA who that might be!), allow me to offer just a few minor corrections....

The total cost of the PMCC outside of the car purchase is $3225.25. The cost of the Porsche Dock, again outside of the purchase of the car is $776 ($739.95 at Suncoast). Of course, you will also need to add sales tax/VAT to that amount as well!

Just trying to assure full disclosure!

Toby

 

[KenU]

daveo, Porsche will owe me over $650, not to mention a correctly gauged supply cable, if what you say turns out to be the case. I have exhausted every possible scenario to try and correct the "red" (inside of my palm) hot supply cable @ 40A charging. And yet, the dealer tells me out of all the Taycans they've sold so far, mine is the only one with this problem. Have bought multiple cars from them forever. Maybe nobody else holds their cable or cares to see what's going on inside that PMCC...

Sponsored