NEMA 14-50 Supply cable heat data

[daveo4EV]

here is the wiring diagram from ClipperCreek for their HCS-60 EVSE - page 21 of the manual - note the picture clearly states

https://store.clippercreek.com/hcs-...906.1307337947.1596817371-62111800.1596666995

Neutral (Not Used)

in fact they even specify to _NOT_ connect the neutral

NOTE: …any two of the legs can be used to provide 208V to the HCS. For example, L1 & L2, or L1 & L3, or L2 & L3. Leave the unused leg open. Do not connect it to a Neutral bar, or to Ground. Be sure the center point is grounded to Earth somewhere in the system.

 

[Miwa]

My current EVSE uses a 6-50, so I figured on the off chance I'll actually take the PMCC out of the bag, I might as well have the same connector. Plus a 6-50 to 14-50 adapter is easy.

 

[HelfFL]

yes it would be best practice when wiring up a NEMA 14-50 plug in one's garage to wire up the neutral - otherwise it can only be used by 240 volt appliances that do not require a neutral - if you plug an RV into a NEMA 14-50 plug- the RV expects the neutral for it's 120 volt usage inside the vehicle - lacking a neutral in the 14-50 plug would be bad ju-ju if you try and use a 240 volt devices that expected it from the 14-50 plug type.

FWIW, when Porsche was trying to diagnose my high temperature readings for my charger and breaker, one of the questions they asked is whether all 4 wires were connected. Porsche said they want all 4 wires connected.

 

[daveo4EV]

Over the years I've installed 240v EVSE's from 8 different manufacturers

1. Tesla
2. ClipperCreek
3. JuiceBox
4. ChargePoint
5. Leviton (Ford)
6. Blink
7. Chevy (AeroEV)
8. Nissan

all of them lack a Neutral for 240 volt applications - so it's not me wiring it up without a neutral there is _NO_ accommodation for a neutral on the connection points inside the box.

and while I can't say 100% it's true that no EVSE uses a neutral in North America - I've sampled most of the big manufactures and it at least appears to be a widely adopted practice and fairly common that the neutral is unused/unavailable in common install scenarios, therefore it would the "uncommon" case that a 240V EVSE requires/utilizes a Neutral and would probably be called out in it's install documentation cause it's not at all common.

 

[KenU]

I think you're basically correct here. The 14-50 cable supplied by Porsche will get very hot under certain circumstances. Not hot enough to fail, but for some reason ($'s??) they chose the less expensive 10 gage wire, which could heat up to an uncomfortable temperature if charging at 40 amps in a high temperature environment.

In my case a couple of weeks ago, after 3 hours of charging at 40A, the cable shot an error message stating it was too hot, disconnect and to lower the power. Don't remember the exact wording but the big red error box was certainly alarming to see and would consider that a "fail" - to me anyway!!
Dialed it down to 24A until the 4 gauge wire and Hubbell receptacle get installed on Monday. Haven't had any issues or error messages since.

 

[daveo4EV]

FWIW, when Porsche was trying to diagnose my high temperature readings for my charger and breaker, one of the questions they asked is whether all 4 wires were connected. Porsche said they want all 4 wires connected.

LOL - well all that proves is Porsche doesn't even know their own connector - I just checked my 14-50 Porsche supply cable - and it doesn't even have a conductor for the neutral inside the cable - annotated picture soon…

 

[Miwa]

LOL, what what Porsche expect the neutral to even do in the US even if it was there?

 

[HelfFL]

LOL - well all that proves is Porsche doesn't even know their own connector - I just checked my 14-50 Porsche supply cable - and it doesn't even have a conductor for the neutral inside the cable - annotated picture soon…

Unfortunately, I was not as educated as I am now from this Forum on these things so I didn't ask Porsche why. Just passing along that it was one of the questions they specifically asked when looking at my heat issue.

Also, to test my wiring and breaker temperatures, I just ordered a ClipperCreek HCS-50P, NEMA 14-50, 40 Amp Charger so that I can compare it with my PMCC.

 

[daveo4EV]

the Porsche EVSE supply cable does not even contain a wire for the neutral - like every other EVSE I've seen over the past 7 years…so it's BS if Porsche is asking for the neutral to be wired up - the inside of Porsche's OWN supply cable shows that to be simply a misunderstanding from the Tech's

the inside of the cable is pretty clearly optimized for 3 conductors (2 hots + ground) - I'm willing to bet there is _NO_ neutral wire even in the cable - the layout of the internals of the connector is pretty clear with some well educated speculation:

• 4 possible "high voltage" conductors locations on the "corners" of the connector
  • 2 in this picture are "used" and big enough for 120 volts
  • 2 in this picture are "un-used/blank" - there is no wire here!!
    • one of them would need wire in this spot if the neutral was being passed to the PMCC - it's black - so the neutral has no connector in this cable.
• center pin - ground
• 6 "small" communication wires - I'm going to guess these are ID pins - the 5-15 supply cable has a different set with conductors - this is clearly a 6-bit binary pattern that the PMCC can use to identify which type of cable is installed and configure itself to "know" what type of cable it's using - 2^6 is 64 different possible combinations - and the software on the PMCC will use this binary pattern to identify the cable.

Porsche doesn't even wire up the Neutral in their own supply cable.

the Neutral is unused in EVSE applications.

 

[Kingske]

the Porsche EVSE supply cable does not even contain a wire for the neutral - like every other EVSE I've seen over the past 7 years…so it's BS if Porsche is asking for the neutral to be wired up - the inside of Porsche's OWN supply cable shows that to be simply a misunderstanding from the Tech's

the inside of the cable is pretty clearly optimized for 3 conductors (2 hots + ground) - I'm willing to bet there is _NO_ neutral wire even in the cable - the layout of the internals of the connector is pretty clear with some well educated speculation:

• 4 possible "high voltage" conductors locations on the "corners" of the connector
  • 2 in this picture are "used" and big enough for 120 volts
  • 2 in this picture are "un-used/blank" - there is no wire here!!
    • one of them would need wire in this spot if the neutral was being passed to the PMCC - it's black - so the neutral has no connector in this cable.
• center pin - ground
• 6 "small" communication wires - I'm going to guess these are ID pins - the 5-15 supply cable has a different set with conductors - this is clearly a 6-bit binary pattern that the PMCC can use to identify which type of cable is installed and configure itself to "know" what type of cable it's using - 2^6 is 64 different possible combinations - and the software on the PMCC will use this binary pattern to identify the cable.

Porsche doesn't even wire up the Neutral in their own supply cable.

the Neutral is unused in EVSE applications.

240 V hot?

 

[daveo4EV]

240 V hot?

Im' confused - the two 120V leg's make for a 240 volt circuit - where did I say 240V hot?

 

[Kingske]

Im' confused - the two 120V leg's make for a 240 volt circuit - where did I say 240V hot?

It is me who is confused. Sorry. Thanks for clarifying.

 

[daveo4EV]

ClipperCreek uses 8 gauge wire for their 40 amp (50 amp breaker) and higher EVSE's

 

[Vim Schrotnock]

Probably the most important thing we all have to remember is to use the proper gage/insulation on the wiring from your circuit breaker to the charger unit. The 40 amps is flowing in this wire threaded through your walls and floors and you certainly want to make sure that wire does not heat up. I used a very highly rated commercial electrician/firm that does this kind of thing routinely, and they installed a 3 conductor line with three 6 AWG conductors and one 10AWG ground. Pic attached.

 

[daveo4EV]

the wire that is feeding my PMCC NEMA 14-50R is 100 amp rated wire (the black wire with the green 100 amp rating label) - and it runs nice to cool during the test - the 10 gauge Porsche wire is the only wire that is getting warm - interestingly the Porsche cable from the PMCC to the Vehicle is also higher gauge wire and is also nice a cool during the test - it's only 10 gauge 14-50 supply cable is that is the smaller 10 gauge wire.

Sponsored