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hard wired EV chargers

Merry Christmas

kec

Senior Member
Location
CT
Occupation
Electrical Contractor
No, "Tesla Wall Connector" is what Tesla calls its EVSE. The current Tesla Wall Connector (version 3, I believe) supports hard-wiring on a 60A circuit to provide 48A continuous to the EV (if its on-board charger is so rated). And putting it on a 60A circuit means that 210.8(F) would not apply.

Cheers, Wayne
Just installed the Tesla wall version 3 and manual states integrated GFCI and no additional required [CCID20]
Also in bold letters: do not install a GFCI circuit breaker. Unit was hardwired in the garage.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Just installed the Tesla wall version 3 and manual states integrated GFCI and no additional required [CCID20]
Yes, CCID20, not Class A GFCI. So the use of the word GFCI in that statement is not accordance with the NEC definitions.

Also in bold letters: do not install a GFCI circuit breaker. Unit was hardwired in the garage.
That instruction translates to "you may not install this product in a manner that would cause the NEC to require a GFCI. Choose a different product if you want to do such an installation."

Cheers, Wayne
 

retirede

Senior Member
Location
Illinois
Yes, CCID20, not Class A GFCI. So the use of the word GFCI in that statement is not accordance with the NEC definitions.


That instruction translates to "you may not install this product in a manner that would cause the NEC to require a GFCI. Choose a different product if you want to do such an installation."

Cheers, Wayne

Does the NEC require a GFCI on any 60A circuit? I can’t think of any.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Does the NEC require a GFCI on any 60A circuit? I can’t think of any.
210.8(B) does starting with the 2017 code.
210.8(B) Other Than Dwelling Units.
All single-phase receptacles rated 150 volts to ground or less, 50 amperes or less and three-phase receptacles rated 150 volts to ground or less, 100 amperes or less installed in the following locations shall have ground-fault circuit-interrupter protection for personnel.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Definitely a good example for the question in post #23, but I think worth noting that in the context of the OP, 625.44 requires EVSEs over 50A to be hardwired.

Cheers,
Wayne
Both 625.44(A) and (B) permit the use of 125/250 volt, single phase, 60 amp receptacles. It appears that is a 2023 change.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Both 625.44(A) and (B) permit the use of 125/250 volt, single phase, 60 amp receptacles. It appeas that is a 2023 change.
I should have known I'd get in trouble just checking the 2020 NEC. : - )

I'm curious why the 2023 NEC 625.44 only allows 60A receptacles for 125/250V 3 pole grounding, not 250V 2 pole grounding. Does the equivalent of NEMA 6-60 not exist, only the equivalent of NEMA 14-60?

Thanks,
Wayne
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
The problem is no one wants to make stuff for just the US market anymore. I know there is a lot of empirical data to back up our 5ma GFCI, but one has to wonder why the rest of the wold has settled on 20 and even 30 ma as their 'gfci'?
I wonder if there is a movement to get at least the IEC / EU to adopt the 5ma GFCI definition then manufacturers would not be so resistant to support it
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I should have known I'd get in trouble just checking the 2020 NEC. : - )

I'm curious why the 2023 NEC 625.44 only allows 60A receptacles for 125/250V 3 pole grounding, not 250V 2 pole grounding. Does the equivalent of NEMA 6-60 not exist, only the equivalent of NEMA 14-60?

Thanks,
Wayne
No idea why. The Public Input which was rejected and the Public Comment which resulted in the code change were submitted by one ChargePoint.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
The problem is no one wants to make stuff for just the US market anymore. I know there is a lot of empirical data to back up our 5ma GFCI, but one has to wonder why the rest of the wold has settled on 20 and even 30 ma as their 'gfci'?
I wonder if there is a movement to get at least the IEC / EU to adopt the 5ma GFCI definition then manufacturers would not be so resistant to support it
The difference is the higher limit is set at a point where the current does not cause ventricular fibrillation and our lower current is based on 95% of the adult population being able to let go of the conducive object.

There is also a difference in the permitted time to trip between the two standards. UL 943 would permit the GFCI to have a trip time of 4.5 seconds for a 7 mA ground fault, while the IEC standards require a trip time of 1/4 second at their rated trip current. The permitted trip time for a 30 mA fault on a UL 943 GFCI is 0.58 seconds.

Note that most GFCIs trip much faster than the maximum permitted trip time...if they didn't, you would have to hold the test button in for over 5 seconds.
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
The difference is the higher limit is set at a point where the current does not cause ventricular fibrillation and our lower current is based on 95% of the adult population being able to let go of the conducive object.

There is also a difference in the permitted time to trip between the two standards. UL 943 would permit the GFCI to have a trip time of 4.5 seconds for a 7 mA ground fault, while the IEC standards require a trip time of 1/4 second at their rated trip current. The permitted trip time for a 30 mA fault on a UL 943 GFCI is 0.58 seconds.

Note that most GFCIs trip much faster than the maximum permitted trip time...if they didn't, you would have to hold the test button in for over 5 seconds.
Interesting thanks, I appreciate how knowledgeable you are on this topic. I am typically in favor of the IEC standards over UL (such as 508) and a was a proponent of harmonizing the two (glad thats mostly done),
But in the case of wet locations I think the EVSE manufacturers should just bite the bullet and integrate a 5ma GFCI into their 'outlets'.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
I keep wondering if there's an engineering difficulty in limiting leakage current to 5ma at higher EVSE amperages. Otherwise why would the manufacturers object to using a GFCI breaker. I second that standards should be harmonized internationally and wonder why CCID20 shouldn't be good enough for the US.
 

retirede

Senior Member
Location
Illinois
I keep wondering if there's an engineering difficulty in limiting leakage current to 5ma at higher EVSE amperages. Otherwise why would the manufacturers object to using a GFCI breaker. I second that standards should be harmonized internationally and wonder why CCID20 shouldn't be good enough for the US.

I suspect it may be related to way they detect the absence of an EGC.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
I suspect it may be related to way they detect the absence of an EGC.
FWIW, the EVSE UL standard covers measuring and limiting ground leakage current, which I assume would also cover during the ground assurance testing of the EVSE. Although I didn't check the limits, I would assume they are below the 4-6 ma GFCI trip threshold.

But if the EVSE puts any current on the EGC, even only 1 or 2 ma, as part of its ground assurance test, then in conjunction with capacitive leakage current on the branch circuit, that could trip a GFCI breaker.

On the other hand, if the EVSE implements CCID5, and if 210.8(F) is interpreted so that the outlet is the vehicle connector itself (what you plug into the car), and the EVSE is hardwired, then there would be no need for upstream GFCI. The question then is if how often the EVSE itself would see more than 5 ma of leakage current from the J1772 cord and the EV, during normal operation.

Cheers, Wayne
 
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