non-gournding receptacle for furnace?

Status
Not open for further replies.
C

colwellk

Member
Location
North Central Texas
If a contractor is replacing a furnace in an older home that has non-grounding type receptacles, is it okay to replace the non-grounding recept. with a GFCI (marked 'no equipment ground')?

It makes sense that this would be okay, but I don't want to tell him wrong.
 
colwellk said:
If a contractor is replacing a furnace in an older home that has non-grounding type receptacles, is it okay to replace the non-grounding recept. with a GFCI (marked 'no equipment ground')?

It makes sense that this would be okay, but I don't want to tell him wrong.
Click to expand...


Take a look at 2 (a)

(D) Replacements. Replacement of receptacles shall comply with 406.4(D)(1) through (D)(6), as applicable.
(1) Grounding-Type Receptacles. Where a grounding means exists in the receptacle enclosure or an equipment grounding conductor is installed in accordance with 250.130(C), grounding-type receptacles shall be used and shall be connected to the equipment grounding conductor in accordance with 406.4(C) or 250.130(C).
(2) Non-Grounding-Type Receptacles. Where attachment to an equipment grounding conductor does not exist in the receptacle enclosure, the installation shall comply with (D)(2)(a), (D)(2)(b), or (D)(2)(c).
(a) A non-grounding-type receptacle(s) shall be permitted to be replaced with another non-grounding-type receptacle(s).
(b) A non-grounding-type receptacle(s) shall be permitted to be replaced with a ground-fault circuit interrupter-type of receptacle(s). These receptacles shall be marked ?No Equipment Ground.? An equipment grounding conductor shall not be connected from the ground-fault circuit-interrupter-type receptacle to any outlet supplied from the ground-fault circuit-interrupter receptacle.
(c) A non-grounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Grounding-type receptacles supplied through the ground-fault circuit interrupter shall be marked ?GFCI Protected? and ?No Equipment Ground.? An equipment grounding conductor shall not be connected between the grounding-type receptacles.
 
Speedskater said:
Why would the furnace need a ground to work, other than safety?
Click to expand...

Flame sensor malfunctions are common when there is no equipment ground, most HVAC guys will not accept connecting a new furnace to a circuit that does not have an equipment grounding conductor, based on this problem alone.

Flame sensor creates a millivolt signal and the EGC is a component of that signal circuit.
 
colwellk said:
If a contractor is replacing a furnace in an older home that has non-grounding type receptacles, is it okay to replace the non-grounding recept. with a GFCI (marked 'no equipment ground')?

It makes sense that this would be okay, but I don't want to tell him wrong.
Click to expand...

Why are we connecting this furnace to a receptacle? It is very likely required to be "hard wired".
 
colwellk said:
If a contractor is replacing a furnace in an older home that has non-grounding type receptacles, is it okay to replace the non-grounding recept. with a GFCI (marked 'no equipment ground')?

It makes sense that this would be okay, but I don't want to tell him wrong.
Click to expand...

This would be a nice application to sell a lite switch for the furnace disconnect in front off of the GFCI. I believe
you'd need another wire between then. IE switch is hot GFCI working.
 
Last edited:
cadpoint said:
This would be a nice application to sell a lite switch for the furnace disconnect in front off of the GFCI. I believe
you'd need another wire between then. IE switch is hot GFCI working.
Click to expand...

Well, I have never seen a permanent furnace fed with a receptacle. For switches, I use what is called an SSU.

I just got a new furnace last year. It is hard wired on it's own circuit with one receptacle at the furnace for the condensate pump. It was inspected and passed without a GFCI in an unfinished basement.

As an electrician, my gut feeling is to have all receptacles in the basement be GFCI, but a failure of said GFCI would cause not only a small flood, but possible furnace damage or failure as well due to the water backing up into the heat exchanger and who knows where else from there.

GFCI's tend to fail faster in humid locations than in dry ones, and it's when it's humid out that the system needs the pump the most.
 
Last edited:
kwired said:
Why are we connecting this furnace to a receptacle? It is very likely required to be "hard wired".
Click to expand...

We have had this discussion before. From the furnace make up box connect a pigtail, the male

end enters the recptacle for power. For power outages connect the male end to the extension

cord connected to generator. The male end removed from recptacle serves as your disconnect

means. Never had a AHJ rejection.
 
K8MHZ said:
That's what I was thinking. It's likely the condensate pump that needs the receptacle. (Like mine)
Click to expand...

I have seen HVAC guys that think it is acceptable to cut the plug off the condensate pump and wire it into the furnace:happysad:

K8MHZ said:
Well, I have never seen a permanent furnace fed with a receptacle. For switches, I use what is called an SSU.

I just got a new furnace last year. It is hard wired on it's own circuit with one receptacle at the furnace for the condensate pump. It was inspected and passed without a GFCI in an unfinished basement.

As an electrician, my gut feeling is to have all receptacles in the basement be GFCI, but a failure of said GFCI would cause not only a small flood, but possible furnace damage or failure as well due to the water backing up into the heat exchanger and who knows where else from there.

GFCI's tend to fail faster in humid locations than in dry ones, and it's when it's humid out that the system needs the pump the most.
Click to expand...
Simple snap switch is acceptable for use as a disconnect for this application and is what I use most of the time. If the furnace requires protection from a fuse (I haven't seen a new one that does in a long time) then the SSU is handy.

GFCI (for 15 and 20 amp 125 volt receptacles) in unfinished basement is still required - even for "dedicated" equipment. If you are worried about loss of power to the pump, I have not seen one that does not have control leads to shut down the controls to the furnace if the pump should fail, but I have seldom seen these leads used. I think they typically connect to a float switch, if the water level is too high - then the pump failed for any reason imaginable. If the owner loses the heat or AC they will not have a big flood because it is not creating additional condensation, and they will call a technician fairly quick if it is not running and don't figure out the problem themselves.

Add: I must say the GFCI requirement for even "dedicated" receptacles is a good idea. Back when we were allowed to install non protected "dedicated" receptacles I used to find many cases of equipment plugged into the dedicated outlet that was not the dedicated equipment. Even when a single outlet instead of a duplex outlet was provided the users would often plug in multioutlet adapters. IMO GFCI's are reliable enough that so called nuisance tripping is not as much of a problem as it once was. Exception may be the really cheap ones that you can find, but you get what you pay for I guess. I seldom have had a call for GFCI problems that I don't find it to be detecting a fault and doing its job. Occasionally there is total failure of the GFCI device and it needs replaced, but it usually will not let power through and will not reset otherwise I wouldn't get a service call in the first place.
 
Last edited:
kwired said:
I have seen HVAC guys that think it is acceptable to cut the plug off the condensate pump and wire it into the furnace. ....
Click to expand...

Educate me please. I'm lost. What is this condensate pump? I'm thinking this is a hot air furnace with an air conditioner, and the pump picks up the water that drops out of the cooled air?

ice
 
Oh lets see. How about CSA standards, NEC 400.7, manufacturers requirement for a switch even if LOCAL code allows cord and plug, and manufacturers requirements for a "permanent" ground.
 
Last edited:
Status
Not open for further replies.
Top