GFCI Receptacles in Parking Garages

E

ERICN

Member
Location
West Chicago, IL.
Occupation
AV Integrator
Our company installed a smaller video wall on the exterior wall of a parking garage in Chicago. Manufacturer of the video wall electrical requirements was pretty simple, the wall required three dedicated receptacles fed by three dedicated 20amp circuits.
Inside the parking garage, directly behind the wall is a enclosed utility room where the main electrical panel is located along with the three dedicated receptacles.
The video wall panel power supplies are fed through the wall and plugged directly into the GFCI protected receptacles.
Problem is: The video walls are tripping the GFCI receptacles, the manufacturer of the video wall is telling us the following-“The leakage current per power supply (from the LED wall power supplis) is 1 mA, so per column would be 9mA. If the GFI is only 5mA, that's not enough. Usually we need equipment-rated GFI, which is 30mA. So, they may need to replace all the GFIs to make the LED wall work.”
In my research of the 2023 NEC, according to 210.8 would an enclosed utility room in a detached parking garage be considered an accessory building? Are the receptacle's in this situation required to be GFCI protected?
 
210.8(B) tells you where you need GFCI protection. I would think the following could apply if this is a typical parking garage:
(8) Indoor damp or wet locations (many times a grey area up to inspector's call)
(10) Garages, accessory buildings, service bays, and similar areas other than vehicle exhibition halls and showrooms
(12) unfinished areas of basements (if this is an underground parking garage and the utility room is unfinished)

Can't you just add more receptacles to these circuits and use more GFCI receptacles that are only supplied from their LINE side. Limit yourself to two power supplies per duplex receptacle if you have to.
 
suemarkp said:
210.8(B) tells you where you need GFCI protection. I would think the following could apply if this is a typical parking garage:
(8) Indoor damp or wet locations (many times a grey area up to inspector's call)
(10) Garages, accessory buildings, service bays, and similar areas other than vehicle exhibition halls and showrooms
(12) unfinished areas of basements (if this is an underground parking garage and the utility room is unfinished)

Can't you just add more receptacles to these circuits and use more GFCI receptacles that are only supplied from their LINE side. Limit yourself to two power supplies per duplex receptacle if you have to.
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Sorry for the late response............Do you think that Sec. 647.7 Exception: Receptacles and attachment plugs rated 125- volt, single phase, 15-20 amperes, and that are identified for use with grounded circuit conductors, shall be permitted in machine rooms, equipment rooms, control rooms............." come into play in this scenario?
 
I doubt it. Did you read 647.1 to see the scope of that article? Do you have a transformer that makes the +- 60VAC that you need to use this article? Even if you do, the exception to me seems to only apply to 647.7(4) meaning you still need GFCI protection but don't need to use a special configuration receptacle identified for use with the 60/120 system.
 
ERICN said:
Sorry for the late response............Do you think that Sec. 647.7 Exception: Receptacles and attachment plugs rated 125- volt, single phase, 15-20 amperes, and that are identified for use with grounded circuit conductors, shall be permitted in machine rooms, equipment rooms, control rooms............." come into play in this scenario?
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We all want exceptions to GFCI, because UL 943 is designed to nuisance trip on Switch Mode Power Supplies (SMPS), among other things.

Before you ad more line-fed GFCI junk, find out how many power supplies it takes to trip each GFCI.

Then decide if GFCI "HF" must be specified, or if AHJ variance must be submitted for lack of "HF" availability, per 90.4 (last paragraph)
 
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ERICN said:
Sorry for the late response............Do you think that Sec. 647.7 Exception: Receptacles and attachment plugs rated 125- volt, single phase, 15-20 amperes, and that are identified for use with grounded circuit conductors, shall be permitted in machine rooms, equipment rooms, control rooms............." come into play in this scenario?
Click to expand...
You might check NFPA 88A Standard for Parking Structures, since NFPA 70 is ambiguous regarding GFCI requirements for parking structures
 
suemarkp said:
210.8(B) tells you where you need GFCI protection. I would think the following could apply if this is a typical parking garage:
(8) Indoor damp or wet locations (many times a grey area up to inspector's call)
(10) Garages, accessory buildings, service bays, and similar areas other than vehicle exhibition halls and showrooms
(12) unfinished areas of basements (if this is an underground parking garage and the utility room is unfinished)

Can't you just add more receptacles to these circuits and use more GFCI receptacles that are only supplied from their LINE side. Limit yourself to two power supplies per duplex receptacle if you have to.
Click to expand...
The basement situation is possibly harder to get around, but then what exactly is does unfinished mean? A room dedicated to equipment isn't typically finished out to the same extent as non utility type areas but is finished enough for its own purposes. but other than that how is a utility/equipment room called a garage, accessory building, service bay or similar area?

A building that is mostly parking garage can still have other areas within that are not actually parking garage spaces.
 
Yes, a closet in a garage may not be a garage, but a closet in an unfinished basement may still be a basement. Im also confused with exactly how these are wired. It sounds like the video wall is outside the closet, but the cords may be passing through the wall into the closet. May be an issue running cords through the wall which could require the receptacles to be moved to be under or next to the video wall.

A picture of this could help and like many code issues could be an inspector's call as to what this is.
 
suemarkp said:
Can't you just add more receptacles to these circuits and use more GFCI receptacles that are only supplied from their LINE side. Limit yourself to two power supplies per duplex receptacle if you have to.
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This still seems the most realistic (read, easiest) option... three GFCI receptacles per column limits the objectionable current to 3mA each, mooting the problem.
 
I used to see a lot of GFCI receptacles trip from appliance loads, but GFCI breakers would hold.
 
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