Backfed GFCI Breaker

Status
Not open for further replies.

Sparkbob

Member
Good morning all.
Pool inspection yesterday. Pool panel in detached structure that supplies 4 pumps and various other loads. Previous correction was to provide GFCI protection for pumps and provide main breaker in this panel as more than 6 operations of the hand are required to disconnect all circuits.
Electrician has installed a 2pole 60amp GFCI breaker as the main, and backfed the breaker. Aside from being required to be fastened in place per 408.36(D), can this breaker be used in a backfed configuration? (Murray c/b by the way) The wiring diagram on the Murray website does not show a backfed configuration. I am inclined to require that the GFCI breaker be moved to the source of the pool panel feeder, and a standard 2pole breaker be installed as the main in the pool panel with appropriate fastening. Any thoughts are appreciated..
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Most GFCI breakers include the words LINE and/or LOAD, this makes them unsuitable for backfeeding.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
If the terminals on the breaker are identified as line a.d load it is not allowed to be backfed.
I have not heard of any GFCI breaker or receptacle that is designed to be backfed.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
If the gfci is feeding the pool panel from another panel then how is it back fed. Something does not seem right.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
If the gfci is feeding the pool panel from another panel then how is it back fed. Something does not seem right.
The GFCI is being used as the "main" breaker in the pool subpanel. Since it is not available as a true main breaker, it is being backfed in a normal breaker location.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
The GFCI is being used as the "main" breaker in the pool subpanel. Since it is not available as a true main breaker, it is being backfed in a normal breaker location.

Gotcha.... I read it totally wrong..:D. I have never seen a gfci hooked up as backfed but I don't see why you couldn't. I have never notice line/load or anything on them- maybe there is...
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I just checked - I have over 100 afci's but I found 1 gfci and it is marked on the side of the breaker "Load Power". In that case JIm is correct - the unit cannot be back fed.
 

domnic

Senior Member
Occupation
Electrical Contractor
backfed

backfed

Good morning all.
Pool inspection yesterday. Pool panel in detached structure that supplies 4 pumps and various other loads. Previous correction was to provide GFCI protection for pumps and provide main breaker in this panel as more than 6 operations of the hand are required to disconnect all circuits.
Electrician has installed a 2pole 60amp GFCI breaker as the main, and backfed the breaker. Aside from being required to be fastened in place per 408.36(D), can this breaker be used in a backfed configuration? (Murray c/b by the way) The wiring diagram on the Murray website does not show a backfed configuration. I am inclined to require that the GFCI breaker be moved to the source of the pool panel feeder, and a standard 2pole breaker be installed as the main in the pool panel with appropriate fastening. Any thoughts are appreciated..

All the loads would have to be 240 volt.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
All the loads would have to be 240 volt.
I do not see the reasoning behind this.
If the GFCI breaker is designed to be compatible with a 120/240 MWBC (i.e. has a separate neutral wire and neutral connection point for the circuit neutral), then it should also be able to support 120 volt loads when backfed. The panel neutral bus will have to be driven through the GFCI breaker rather than directly from the feeder neutral.

However, even if only 240 volt loads are present, it cannot be installed this way under NEC if LINE and LOAD terminals are identified on the breaker.
 

kwired

Electron manager
Location
NE Nebraska
All the loads would have to be 240 volt.

I do not see the reasoning behind this.
If the GFCI breaker is designed to be compatible with a 120/240 MWBC (i.e. has a separate neutral wire and neutral connection point for the circuit neutral), then it should also be able to support 120 volt loads when backfed. The panel neutral bus will have to be driven through the GFCI breaker rather than directly from the feeder neutral.

However, even if only 240 volt loads are present, it cannot be installed this way under NEC if LINE and LOAD terminals are identified on the breaker.

I don't know about the Murray breaker in the OP, but I do know that Square D QO series 60 amp GFCI does not have a neutral terminal and can not be used for 120/240 circuits - it is for straight 208 or 240 only.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I don't know about the Murray breaker in the OP, but I do know that Square D QO series 60 amp GFCI does not have a neutral terminal and can not be used for 120/240 circuits - it is for straight 208 or 240 only.
I don't know what Murray breaker the OP is looking at either, but this one definitely has a neutral terminal and a neutral pigtail.

I do see a Square D breaker like the one you describe, but I also see 120/240 breakers that do have a load-side neutral terminal.
Seems to be a feature of the QO line.
 
Last edited:

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Why does the panel need a main. It does not appear to be service.
The panel does not need a main, but that apparently seemed to be the easiest way to install GFCI protection for all of the devices attached to the panel. Maybe no room for a GFCI breaker at the other end of the feeder?
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
Why does the panel need a main. It does not appear to be service.

The panel does not need a main, but that apparently seemed to be the easiest way to install GFCI protection for all of the devices attached to the panel. Maybe no room for a GFCI breaker at the other end of the feeder?

The panel would either need a main or a disconnect before the panel. OP said there were more than "six throws of the hand" needed to turn off all the breakers.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
The panel would either need a main or a disconnect before the panel. OP said there were more than "six throws of the hand" needed to turn off all the breakers.
+1
And therefore putting the GFCI at the feeding panel to also serve as that disconnect would seem to be the way to go. :)
 

kwired

Electron manager
Location
NE Nebraska
The panel would either need a main or a disconnect before the panel. OP said there were more than "six throws of the hand" needed to turn off all the breakers.

+1
And therefore putting the GFCI at the feeding panel to also serve as that disconnect would seem to be the way to go. :)

OP also said this panel was in a separate structure, so if there were more than six breakers in the panel a main at the separate structure is needed.

Easiest solution is likely to put the GFCI in the other structure as the feeder breaker, and a main is still needed in the pool shed, other option is to place another (two space) panel in the pool shed with the GFCI installed in it and supply the existing panel from that GFCI.

If the GFCI is a 60 amp with no neutral (like the Square D mentioned earlier) and there are neutral loads then you are out of luck with the GFCI main if a 60 amp feeder is what is necessary.
 

domnic

Senior Member
Occupation
Electrical Contractor
NEUTRAL

NEUTRAL

I do not see the reasoning behind this.
If the GFCI breaker is designed to be compatible with a 120/240 MWBC (i.e. has a separate neutral wire and neutral connection point for the circuit neutral), then it should also be able to support 120 volt loads when backfed. The panel neutral bus will have to be driven through the GFCI breaker rather than directly from the feeder neutral.

However, even if only 240 volt loads are present, it cannot be installed this way under NEC if LINE and LOAD terminals are identified on the breaker.
The panel neutral bus will have to be driven through the GFCI breaker. HOW would this be done ?
 
Status
Not open for further replies.
Top