GFCI TIA for A/C Units

Dennis Alwon

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Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Here is another

NFPA 70®-2020 Edition National Electrical Code® TIA Log No.: 1564 Reference: 210.8(F) Comment Closing Date: April 28, 2021 Submitter: Laura Petrillo-Groh, Air-Conditioning, Heating & Refrigeration Institute (AHRI) www.nfpa.org/70 1. Revise Section 210.8(F) to read as follows: 210.8 Ground-Fault Circuit-Interrupter Protection for Personnel. … (F) Outdoor Outlets. All outdoor outlets for dwellings, other than those covered in 210.8(A)(3), Exception to (3), that are supplied by single-phase branch circuits rated 150 volts or less to ground, 50 amperes or less, shall have ground-fault circuit-interrupter protection for personnel. This requirement shall become effective January 1, 2023, for ducted or ductless mini-split and multi-split-type heating/ventilating/air-conditioning (HVAC) equipment, including variable refrigerant flow (VFR), variable air volume (VAV), and other HVAC, or water heating units employing power conversion equipment as a means to control compressor speed. Informational Note: Power conversion equipment is the term used to describe HVAC equipment components that are commonly referred to as the variable speed drive. The use of power conversion equipment to control compressor speed differs from multi-stage compressor speed control. Exception: Ground-fault circuit-interrupter protection shall not be required on lighting outlets other than those covered in 210.8(C). Substantiation: While this expanded GFCI protection in the 2020 NEC presents a clear enhancement to safety, HVAC component and equipment safety standards are not harmonized with GFCI amperage limits. Until both equipment and component standards are updated, designers, installers, AHJs, and consumers are forced to choose between an NEC 2020 compliant installation or an operational installation. In jurisdictions that have adopted 2020 NEC with 210.8(F) intact, there have been numerous instances of field tripping of the GFCI breaker on ductless mini splits and units containing power conversion equipment. In these cases, the only solution was for the AHJ to approve a temporary allowance to install a non-GFCI breaker. Known instances of attempt to use GFCI breaker on products with inverter driven compressors, with only resolution to provide heating/cooling to residence by using non-GFCI breaker:
It goes on to list areas where they had issues.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I think that this is a dumb requirement to begin with. Was there any real substantiation in the original PI?
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Here is the story

It's terrible that someone died but one death and you come up with a requirement that the equipment manufacturer cannot comply with. Whatever happened to common sense, like setting a future adoption date so that the people making AC units can actually have them work. :rolleyes:
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I agree.... It is getting crazy. The manufacturers probably dug this up and the a/c boys haven't been able to design it to work....
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I agree.... It is getting crazy. The manufacturers probably dug this up and the a/c boys haven't been able to design it to work....
Again not to diminish someone dying but one death and this is the solution? What if they never solve this? Should we then abandon air conditioning units?
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Like the other one, this has been previously submitted and rejected. This one has not really been changed from the previously rejected one.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Again not to diminish someone dying but one death and this is the solution? What if they never solve this? Should we then abandon air conditioning units?
Part of the substantiation for this TIA said:
These concerns are emergency in nature as this issue impacts consumers who would be relying on this equipment for their only or primary source of heating or cooling. Tripping of the GFCI breakers could result in dangerous conditions for people in cold or hot weather.
...
AHRI notes, there has not yet been a full peak cooling season while NEC 2020 requirements are in place and our expectation is that installations compliant with 210.8(F) will cause widespread non-operational applications of cooling in peak cooling season.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
Of all the equipment that could be come energized a condensing unit would seem to be the least likely as the line set would be another fault return path through the air handling unit that should have cleared the fault. Was the airhandler/furnace EGC lacking as well?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Of all the equipment that could be come energized a condensing unit would seem to be the least likely as the line set would be another fault return path through the air handling unit that should have cleared the fault. Was the airhandler/furnace EGC lacking as well?


Who knows...I didn't read the after story but it could have been a 2 wire system in the home. It is interesting that people pick him up off the unit but they didn't get caught in that web.

I also read some other cases where people got shocked by an a/c unit

https://www.valleycentral.com/news/...-shocked-after-son-touches-ac-unit-while-wet/
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
I would venture a guess that it's a given that poorly maintained and installed units (like that one) wouldn't have GFI protection even if it was required.

-Hal

Logic shines for light years! :)


Of all the equipment that could be come energized a condensing unit would seem to be the least likely as the line set would be another fault return path through the air handling unit that should have cleared the fault. Was the airhandler/furnace EGC lacking as well?

My money is either poor documentation/journalism of the incident or a hack job where code wouldn't have mattered anyways.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Here is the story




Who knows...I didn't read the after story but it could have been a 2 wire system in the home. It is interesting that people pick him up off the unit but they didn't get caught in that web.

I also read some other cases where people got shocked by an a/c unit

https://www.valleycentral.com/news/...-shocked-after-son-touches-ac-unit-while-wet/

Unplugged the unit?


I'll let you in on a little secret. Its not the anecdotes themselves which the NFPA really worries or cares about, but rather silently mitigating potential self inflicted litigation for their failure to elucidate 250.4 (A) 5. Or rather manufacturers seizing on the "opportunity" of the blunder... Ego, ignorance, greed and litigation based reasoning are one heck of a drug.
 
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