EV chargers with Integral GFCI

Status
Not open for further replies.

gndrod

Senior Member
[210.8(A)(2)] Garage requires all 125 -V, 1ph 15 & 20A receptacles to have GFCI protection...etc. 2008 cycle. Article 625 does not seem to have an exception to the 210.8 requirement when EV Charger stations have included a GFCI function to the 125V interface. Would an ROP submission such as stating the above for substantiation be acceptable for including an exception as follows:
(210.8(A)(2) Exception)
Recommendation: Add Exception to (2): "Receptacles that have GFCI protection integral with EV Charger Station equipment and are supplied from a dedicated branch circuit without a GFCI protection shall be permitted."

Any comments would be appreciated.
 

hurk27

Senior Member
If the GFCI is on the charging circuit side of the transformer in these chargers then there would be no protection for the line side of the unit, and a fault on the line side could cause the unit to have voltage present on it without GFCI protection, but there should not be any problem operating one of these in a GFCI protected circuit as the newer GFCI's have gotten better to nascent tripping, I think the reason there is a GFCI built into them is a GFCI on the line side of a transformer will only see a line to line current if a fault was to happen on the load side, (charging side) during the EV-1 days some of the chargers took a 240 volt 30 amp circuit which didn't require GFCI, and I've heard of 240 volt 50 amp circuits being installed for some, but not sure of the source.
 

gndrod

Senior Member
EV Charger in cord/Vehicle

EV Charger in cord/Vehicle

I think the reason there is a GFCI built into them is a GFCI on the line side of a transformer will only see a line to line current if a fault was to happen on the load side, (charging side) during the EV-1 days some of the chargers took a 240 volt 30 amp circuit which didn't require GFCI, and I've heard of 240 volt 50 amp circuits being installed for some, but not sure of the source.
Hi Wayne,
I am not sure how to describe the charging setup other than, the charger cord head has solid state sensing and conversion circuitry that regulates the charge rate drawn by the vehicle AC to DC converter with an integral GFCI circuit within the vehicle.

The vehicle, Tesla Motor Co in this case, uses three different plug-in adapters to hook-up to 20, 30, and 60 Amp wall receptacles to match the charge rate needed for slow, medium and fast charging. None of the interfaces are to be GFCI protected at the wall BC output according to the instructions.

This is part of why I am suggesting a change in the NEC 2014 cycle. I have emailed the manufacturer for more details but have not gotten any reply as of this time. Probably proprietary reasons for their silence as the circuitry is unique to the 210.8(A)(2) requirement.
 

don_resqcapt19

Moderator
Staff member
The vehicle, Tesla Motor Co in this case, uses three different plug-in adapters to hook-up to 20, 30, and 60 Amp wall receptacles to match the charge rate needed for slow, medium and fast charging. None of the interfaces are to be GFCI protected at the wall BC output according to the instructions.
Sorry, but the manufacturer's instructions cannot over rule the NEC. The 20 amp receptacle outlet requires GFCI protection and I see no need for an exception. If the charger will not work on a GFCI protected circuit, it is not safe to use.
 

gndrod

Senior Member
Sorry, but the manufacturer's instructions cannot over rule the NEC. The 20 amp receptacle outlet requires GFCI protection and I see no need for an exception. If the charger will not work on a GFCI protected circuit, it is not safe to use.
I agree with you on that. Unfortunately prior to the 2008 NEC change, the Tesla design was made to circumvent the millions of garages built without protection by integrating their own GFCI protection.

Sort of a catch 22 for the millions of home owners to update their garage outlets upon purchasing an EV. I believe Tesla intended on covering that liability with their integral GFCI protection except for the existing outdoor charger stations prior to the 2008 NEC GFCI ruling. It appears that future collaboration between the Code and the automotive industry standardization is on course for updates as the technology progresses.
 

don_resqcapt19

Moderator
Staff member
I agree with you on that. Unfortunately prior to the 2008 NEC change, the Tesla design was made to circumvent the millions of garages built without protection by integrating their own GFCI protection. ...
How does the internal GFCI protection prevent you from plugging the equipment into the GFCI protected receptacle in the garage?
 

gndrod

Senior Member
How does the internal GFCI protection prevent you from plugging the equipment into the GFCI protected receptacle in the garage?
Don,
I am not sure what you are asking here. After or prior 2008 a GFCi outlet probably trips not allowing the internal vehicle GFCI to operate forcing the operator to find another receptacle outlet. I believe the design was intended to protect personnel in garages that did not have a GFCI prior to the new 2008 NEC requirement. I do not know how the Tesla technology is applied in order to answer your question. You might go on the Tesla website and see if there is additional information that I might have missed. Sorry.
 

gndrod

Senior Member
Don,
The Tesla website is constantly changing so the charging segment I bookmarked is no longer available. The best bet is to Google up the Tesla Motor Inc. for a search within the site.
 

hurk27

Senior Member
What Don is trying to get at is if this charger causes a GFCI to trip then it has a leakage current that is not allowed whether it is plugged into a GFCI or not, there are many regulations and UL standards that would prevent such a device to be marketed to consumers, and its not the GFCI in the charger that is a problem because GFCI's can be loaded of GFCI's with no problems, remember a newer Hair drier has a GFCI in its cord and most people plug it into there bathroom GFCI and it works fine. If this charger has a leakage current the is higher then the 5ma it takes to trip a GFCI then it is a hazard because it is placing a current on the grounding conductors that is not allowed.
 

hurk27

Senior Member
Ok I searched their web site, and found this info, I think your reading things wrong


Charger info for electricians

Tesla recommends installing a NEMA 14-50R receptacle connected to a non GFCI 50A breaker.
this is a 240 volt 50 amp RV/welder (not dryer as is said) receptacle and is not required to be GFCI protected in the NEC, also looking at the charging times, you would be nuts at charging with anything less as on 120 volts at 15 amps takes a whooping 48 hours, 120 volts at 20 amps 37 hours, the above 50 amp receptacle takes only 6 hours, so it will be fully charged by the time you wake up for work, and if you can supply it with 90 amps, it takes only 4 hours to fully charge. but any 240 volt method does not require a GFCI in the NEC, and even a 120 volt 30 amp wouldn't but they dont show a NEMA 5-30 receptacle option:confused:

web site is HERE
 

gndrod

Senior Member
Ok I searched their web site, and found this info, I think your reading things wrong


Charger info for electricians



this is a 240 volt 50 amp RV/welder (not dryer as is said) receptacle and is not required to be GFCI protected in the NEC, also looking at the charging times, you would be nuts at charging with anything less as on 120 volts at 15 amps takes a whooping 48 hours, 120 volts at 20 amps 37 hours, the above 50 amp receptacle takes only 6 hours, so it will be fully charged by the time you wake up for work, and if you can supply it with 90 amps, it takes only 4 hours to fully charge. but any 240 volt method does not require a GFCI in the NEC, and even a 120 volt 30 amp wouldn't but they dont show a NEMA 5-30 receptacle option:confused:

web site is HERE
Wayne,
There is/was a more detailed breakdown of the charging system that I am not finding on the current Tesla site data. The specs given for the variations of charging interface is the Clipper Creek Inc. charging conversion for Tesla. Dang. It is out there somewhere. I Googled up Clipper Creek and the data has been deleted. Go figure, this data was before the release of the 2008 NEC.
 
Status
Not open for further replies.
Top