twilli3967
Member
are you allowed to power the gfci off the disconnect for the a/c or do you need a seperate line to feed the gfci.
A/C disconnect and GFCI
- Thread starter twilli3967
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jwelectric
Senior Member
- Location
- North Carolina
Re: A/C disconnect and GFCI
not the load side
twilli3967
Member
Re: A/C disconnect and GFCI
Electrical and Hvac...I know you are allowed to power it off the line side, we are currently using the cutler hammer disconnect/gfci combination disconnect.
One of my hvac tech called me today and said that the hvac inspectors were approving them and some companies were powering them by tapping off the line side and tricked the gfci by using the ground as a neutral and ground. While I know this is not approved under the NEC, wouldn't you have to pull a neutral and also provide some type of ocpd as wel?
Electrical and Hvac...I know you are allowed to power it off the line side, we are currently using the cutler hammer disconnect/gfci combination disconnect.
One of my hvac tech called me today and said that the hvac inspectors were approving them and some companies were powering them by tapping off the line side and tricked the gfci by using the ground as a neutral and ground. While I know this is not approved under the NEC, wouldn't you have to pull a neutral and also provide some type of ocpd as wel?
Re: A/C disconnect and GFCI
I have only seen (and inspected) these on site and in each case the GFCI was wiredf from a 15-20 circuit not associated with the HVAC unit.
I assume they do not come with the recept. pre-wired...only a disconnect and recept mounted in the same NEMA 3R enclosure. Is this not correct?
I have only seen (and inspected) these on site and in each case the GFCI was wiredf from a 15-20 circuit not associated with the HVAC unit.
I assume they do not come with the recept. pre-wired...only a disconnect and recept mounted in the same NEMA 3R enclosure. Is this not correct?
luke warmwater
Senior Member
Re: A/C disconnect and GFCI
That is correct.
Re: A/C disconnect and GFCI
Gents,
I have not seen them yet.but in the prints and specs for the Wholesale Warehouse we just started the A/C's come complete with feed pipe access without roof penatration,built in disconect,and GFCI recpt. also built in and all by Manafacturer
frank
Gents,
I have not seen them yet.but in the prints and specs for the Wholesale Warehouse we just started the A/C's come complete with feed pipe access without roof penatration,built in disconect,and GFCI recpt. also built in and all by Manafacturer
frank
sceepe
Senior Member
Re: A/C disconnect and GFCI
This is a great way to kill someone. If you find out who is doing this, you need to report them to the AHJ and they need to have their liscence revoked (IMO). They just made an incredibly dangerous situation to avoid pulling 2 #12's to the roof.
I would think that if your HVAC is supplied from lets say a 90A 2 pole breaker and you tapped one leg to power the gfci receptacle, you have just installed a 15 or 20 amp receptacle on a 90 amp circuit. To make matters worse, the equipment grounding conductor is used a neutral and a ground. Now you have a ground loop (and perhaps no fault current return path) and you are purposely putting current on the equipment grounding conductor. So now, some poor dude can go up there with his drill, accidentally nick a wire and have 80 amps run through him until the freaking receptacle melts.
This is a great way to kill someone. If you find out who is doing this, you need to report them to the AHJ and they need to have their liscence revoked (IMO). They just made an incredibly dangerous situation to avoid pulling 2 #12's to the roof.
sceepe
Senior Member
Re: A/C disconnect and GFCI
Frank,
Who is manufacturer?
I assume this is only for 120/208 units??
Do they require a neutral be supplied???
Are the integral disconnects supplied with OCPD???
If GFCI receptacle in a while in use cover?? Rooftop is a wet location eh??
Tell us more...
Frank,
Who is manufacturer?
I assume this is only for 120/208 units??
Do they require a neutral be supplied???
Are the integral disconnects supplied with OCPD???
If GFCI receptacle in a while in use cover?? Rooftop is a wet location eh??
Tell us more...
stud696981
Senior Member
Re: A/C disconnect and GFCI
The ones I have seen were designed to be put on a separate circuit for the outlet. Reason being most AC units have a larger breaker or fuse then the 20amp MAX for the outlet.
The only reason they were grouped in the same housing was for convenience and to save installation time.
[ August 16, 2005, 10:17 AM: Message edited by: stud696981 ]
The ones I have seen were designed to be put on a separate circuit for the outlet. Reason being most AC units have a larger breaker or fuse then the 20amp MAX for the outlet.
The only reason they were grouped in the same housing was for convenience and to save installation time.
[ August 16, 2005, 10:17 AM: Message edited by: stud696981 ]
twilli3967
Member
Re: A/C disconnect and GFCI
http://www.3rdwav.com/ch.htm
thanks to all for your help. I sent an email to the local inspection deapartment regarding this issue an am awaiting a reply. We seem to have some what of a fight between the two inspection depts HVAC vs Electrial.
Hopefully they will resolve this before someone is injury or killed.
http://www.3rdwav.com/ch.htm
thanks to all for your help. I sent an email to the local inspection deapartment regarding this issue an am awaiting a reply. We seem to have some what of a fight between the two inspection depts HVAC vs Electrial.
Hopefully they will resolve this before someone is injury or killed.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Re: A/C disconnect and GFCI
Thanx for the link, T-Willi. The receptacle is obviously designed to be separately fed, as Augie, Luke, and Stud mentioned. I guess the feeds can share a conduit.
The PDF says that the unit is suitable as service equipment. While I may not use it for utility power, it would make a good generator feed-in disconnect.
Thanx for the link, T-Willi. The receptacle is obviously designed to be separately fed, as Augie, Luke, and Stud mentioned. I guess the feeds can share a conduit.
The PDF says that the unit is suitable as service equipment. While I may not use it for utility power, it would make a good generator feed-in disconnect.
sceepe
Senior Member
Re: A/C disconnect and GFCI
Looking at the Cutler hammer device, I don't like it. It is way to tempting to just install a little jumper from the terminals for the disconnect to the terminals for the receptacle. (ignoring the fact that you would be putting a 20 amp duplex on a 60 amp branch circuit). Also, it claims to be for residential or light commercial. Probably not beefy enough for my commercial work.
Heres an NEC question. If the disconnect had OCPD for the receptacle and a neutral terminal in the disconnect, would NEC let you tap the 120/208 feed to the HVAC for the recpt?
Looking at the Cutler hammer device, I don't like it. It is way to tempting to just install a little jumper from the terminals for the disconnect to the terminals for the receptacle. (ignoring the fact that you would be putting a 20 amp duplex on a 60 amp branch circuit). Also, it claims to be for residential or light commercial. Probably not beefy enough for my commercial work.
Heres an NEC question. If the disconnect had OCPD for the receptacle and a neutral terminal in the disconnect, would NEC let you tap the 120/208 feed to the HVAC for the recpt?
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Re: A/C disconnect and GFCI
As for the tap, only if there is an insulated neutral available.
It's up to the electrician to avoid temptation to knowingly do something wrong.
As for the tap, only if there is an insulated neutral available.
Re: A/C disconnect and GFCI
Sceepe,
Got the info requested today.
The units are made by Trane,The disconnect is a C.B. and it has provisions for a padlock to lock in open position,The voltage on these units is 480vac 3ph 3W , The line side of disc. is tapped to a transformer the ocp is 15a/120vac to flush mount GFCI with w.p. cover.
Finally there is another metal top hinged cover that covers the c.b. and GFCI and that has a tab when closed for another padlock. Also the supply power to unit does not need a roof penatration as it pokes out into the cieling space below.
This company is after FFAAASSSTTTTTT opening and this is as fast as it can get.
Random Trane model# YHCO36A4
If more info needed I'll get it.
frank
Sceepe,
Got the info requested today.
The units are made by Trane,The disconnect is a C.B. and it has provisions for a padlock to lock in open position,The voltage on these units is 480vac 3ph 3W , The line side of disc. is tapped to a transformer the ocp is 15a/120vac to flush mount GFCI with w.p. cover.
Finally there is another metal top hinged cover that covers the c.b. and GFCI and that has a tab when closed for another padlock. Also the supply power to unit does not need a roof penatration as it pokes out into the cieling space below.
This company is after FFAAASSSTTTTTT opening and this is as fast as it can get.
Random Trane model# YHCO36A4
If more info needed I'll get it.
frank
jjhoward
Senior Member
- Location
- Northern NJ
- Occupation
- Owner TJ Electric
Re: A/C disconnect and GFCI
I like the looks of that Cutler Hammer box. I will check with my supply house tomorrow.
Question: Does the NEC require a grnding conductor outside of the conduit that is carrying the feed to the A/C unit from the disconnect?
Thank you.
I like the looks of that Cutler Hammer box. I will check with my supply house tomorrow.
Question: Does the NEC require a grnding conductor outside of the conduit that is carrying the feed to the A/C unit from the disconnect?
Thank you.
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