Can a GFCI breaker feed a sub panel?

(b lee hall) #1

Can you feed a sub panel with a GFCI breaker? In order to save $ on multiple GFCI breakers and/or receptacles I want to feed a sub panel to a shop/garage with a 50A GFCI breaker but am not sure if it will nuisance trip because of multiple circuits. The branch circuits in the shop/garage are for an air compressor, lights, and receptacles (and a small beer refrigerator).

(Mark E. Glowczynski) #2

I don't believe fridges should be on GFCI's.

(Roy Lewis, CMI - North Florida Inspector) #3

My question is.... Why the heck would you even think of it.
Do they even make a 50-amp GFCI breaker ?
Do it correctly and have a pro do it for you.
It will usually save you money down the road.

[quote="b_lee_hall, post:1, topic:80039"]

Can you feed a sub panel with a GFCI breaker? In order to save $ on multiple GFCI breakers and/or receptacles I want to feed a sub panel to a shop/garage with a 50A GFCI breaker but am not sure if it will nuisance trip because of multiple circuits. The branch circuits in the shop/garage are for an air compressor, lights, and receptacles (and a small beer refrigerator).
[/QUOTE]

(Roy D. Cooke, Sr) #4

[quote="b_lee_hall, post:1, topic:80039"]

Can you feed a sub panel with a GFCI breaker? In order to save $ on multiple GFCI breakers and/or receptacles I want to feed a sub panel to a shop/garage with a 50A GFCI breaker but am not sure if it will nuisance trip because of multiple circuits. The branch circuits in the shop/garage are for an air compressor, lights, and receptacles (and a small beer refrigerator).
[/QUOTE]

Never would I think of doing this Poor way to save a little bit of money.
I can see a lot of unneeded aggravation .

(Chris Jacobi, HI01200061) #5

50 amp breaker? For outlets? How many outlets are you putting in? You can get two or three rooms on one 20 amp breaker.

(Paul W. Abernathy) #6

[quote="mglowczynski, post:2, topic:80039"]

I don't believe fridges should be on GFCI's.
[/QUOTE]

Now why on earth would you make a statement like that. Since when is a fridge full of food more important than the loss of life. With that general statement it appears you also believe that fridges in residential garages should not be on GFCI. Their is documented proof that deaths have occurred via Garage Door Openers and Metal Tracks and the frame of fridges in garages. In fact, in the last 10 years we have seen no less than 3 of these cases.

Now 3 in 10 years may be acceptable to you...but any preventable loss of life is a big deal to me. Many years ago the DEFROST cycle would tend to trip a GFCI simply because the standards allowed for Freezers(not fridges) to exceed the 6mA limit of the personal protection requirement of the NEC for a brief moment in that cycle....now days that is not an issue.

We have over 50 years of tried and trusted research on GFCI Technology and when installed properly are extremely reliable. When they do trip I can bet their is a reason why it has happened and an investigation should be done on the appliance and the circuit by a licensed and bonded electrical contractor.

(Paul W. Abernathy) #7

[quote="b_lee_hall, post:1, topic:80039"]

Can you feed a sub panel with a GFCI breaker? In order to save $ on multiple GFCI breakers and/or receptacles I want to feed a sub panel to a shop/garage with a 50A GFCI breaker but am not sure if it will nuisance trip because of multiple circuits. The branch circuits in the shop/garage are for an air compressor, lights, and receptacles (and a small beer refrigerator).
[/QUOTE]

Ok, I will answer your question for you as it appears no one has yet their are many opinions to how they would tackle this.

The answer is YES, they do make a 50A GFCI (Class A) Circuit Breaker that can be used on a feeder (same as it would be used on a branch circuit to a hottub). Even if you divide the paths down stream of this device remember that the feeder is where the device is located so all currents returning back will have to come through the feeder and circuit breaker.

Remember 6mA is the threshold for GFCI operation and anything under 4mA will not set off the device. We tend to use the term Nominal 5mA when describing these devices.

If all the current going out on the feeder does not return through the feeder and GFCI device you will experience an activation of the GFCI Device. Remember, I would never call a trip of a GFCI a nuisance because you have to determine all the factors to be considered a nuisance by definition.

Hope this was helpful. FYI- We also see this method done in Marinas from time to time as well under the exception to the general GFP rule of Section 555.3 [2011 NEC]. Since you did not ask about Marina's I wont go down that confusing path.

Hope you found this helpful.

(Marcel Gratton, CMI) #8

[quote="pabernathy, post:6, topic:80039"]

We have over 50 years of tried and trusted research on GFCI Technology and when installed properly are extremely reliable. When they do trip I can bet their is a reason why it has happened and an investigation should be done on the appliance and the circuit by a licensed and bonded electrical contractor.
[/QUOTE]

Almost half the GFCI receptacle I test are faulty, so much for being extremely reliable well maybe the newer ones...

(Marcel Gratton, CMI) #9

[quote="pabernathy, post:6, topic:80039"]

We have over 50 years of tried and trusted research on GFCI Technology and when installed properly are extremely reliable. When they do trip I can bet their is a reason why it has happened and an investigation should be done on the appliance and the circuit by a licensed and bonded electrical contractor.
[/QUOTE]

Almost half the GFCI receptacle I test are faulty, so much for being extremely reliable.

Maybe the newer ones are better...

(Marcel Gratton, CMI) #10

I see those breakers (double pole, 240V) all the time for hot tubs but I heard that they are expensive.

(Bob Elliott, 450.0002662) #11

Marcel I see panel breaker GFCI's all the time.
Primary use seems to be in modern condos.

Mainly it is a situation where reaching the outlet would be difficult such as when they tile the sides of the tub and eliminate the hatch.(yes makes pump removal difficult).

>>>>Paul I saw your reply however what is your opinion on using a 50 amp GFCI breaker to feed a remote distribution panel ?

(Marcel Gratton, CMI) #12

[quote="belliott, post:11, topic:80039"]

Marcel I see panel breaker GFCI's all the time.
Primary use seems to be in modern condos.
[/QUOTE]

Me too (120V), usually for Jacuzzi tub or exterior receptacles.

(Roy D. Cooke, Sr) #13

[quote="mgratton, post:9, topic:80039"]

Almost half the GFCI receptacle I test are faulty, so much for being extremely reliable.

Maybe the newer ones are better...
[/QUOTE]

Interesting what faults do you find with them and how does it show up .
Thanks Roy

(Marcel Gratton, CMI) #14

[quote="rcooke, post:13, topic:80039"]

Interesting what faults do you find with them and how does it show up .
Thanks Roy
[/QUOTE]

Press the receptacle test button and they don't trip, how do you test them?

(Roy D. Cooke, Sr) #15

[quote="mgratton, post:14, topic:80039"]

Press the receptacle test button and they don't trip, how do you test them?
[/QUOTE]

The same way .I guess I have been lucky did not find many .

Every one you find might save some ones life, Good for you all the best ... Roy

(Paul W. Abernathy) #16

Hello All,

I thought I actually made it clear my opinion of using a 50A GFCI Circuit Breaker (in this case) ahead of a remote distribution panel as perfectly acceptable if that's what someone wants to do. In fact, it is done all the time in an attempt to comply with Section 555.3. While it is not normally practicable the electrons do not know the difference and the leakage current is constant regardless of its location when using a true GFCI Device.

In terms of the reliability question (not sure who asked that) I believe that we have over 50 years of solid research and data that shows GFCI Devices are extremely reliable and this was increased even more then UL 943 was revamped in 2003-2004 time frame. So the older GFCI's that you may experience an issues with could possibly be an MOV issued which is the design fail component of a GFCI....so older models prior to 2003 I would always recommend replacement with new models simply because the standards have changed and a more robust design was implemented by the manufacturers.

Hope that explains it.

(system) #17

The 60A GFCI feeder breaker that supplies my pool panel nuisance trips all the time. I believe the VS pool pump motor may be the cause. There are no undesirable neutral-ground bonds down stream of the GFCI feeder breaker. In my research to determine the cause of my GFCI nuisance tripping, I’ve come across quite a few examples of similar issues around pool pump motors and particularly VS pool pump motors. In my experience it is almost always better to not have a GFCI protecting a motor. I’ve done it on my pool equipment because code required it and I do believe it will ultimately be safer even though I experience nuisance tripping.

I'm a registered Professional Electrical Engineer with nearly 30 years of experience, both behind a desk and in the field. I find Mr. Abernathy's response informative, but quite condescending and arrogant.... I’ve found that same attitude with many folks involved in creating and enforcing codes…. Nobody wants to see accidents involving electrical equipment, but you could loose the high and mighty bit…….. Just keep to the facts…..

(Paul W. Abernathy) #18

[quote="belliott, post:11, topic:80039"]

Marcel I see panel breaker GFCI's all the time.
Primary use seems to be in modern condos.

Mainly it is a situation where reaching the outlet would be difficult such as when they tile the sides of the tub and eliminate the hatch.(yes makes pump removal difficult).

>>>>Paul I saw your reply however what is your opinion on using a 50 amp GFCI breaker to feed a remote distribution panel ?
[/QUOTE]

Well Hello their Bob.....my opinion is, if the NEC permits it then I am ok with it.

Again a GFCI device is designed to work at specific perimeters and if within those perimeters the device activates then it is doing so for a reason.

"215.9 Ground-Fault Circuit-Interrupter Protection for
Personnel. Feeders supplying 15- and 20-ampere receptacle
branch circuits shall be permitted to be protected by a
ground-fault circuit interrupter in lieu of the provisions for
such interrupters as specified in 210.8 and 590.6(A)."

So that is one example of where the NEC says it is ok....

550.13(B) seems to accept it....

"Feeders supplying branch circuits shall be permitted to
be protected by a ground-fault circuit-interrupter in lieu of
the provision for such interrupters specified herein."

So other than where the NEC specifically calls for the protection to be in the branch circuit....then I see no issue with being in the feeder...again where applicable.

(Paul W. Abernathy) #19

[quote="Unregistered, post:17, topic:80039"]

I find Mr. Abernathy's response informative, but quite condescending and arrogant.... I’ve found that same attitude with many folks involved in creating and enforcing codes…. Nobody wants to see accidents involving electrical equipment, but you could loose the high and mighty bit…….. Just keep to the facts…..
[/QUOTE]

Really...on what planet?

I would expect that from an "Unregistered" response rather than someone who really knows me and knows what I say...but again I never cared to please everyone and never got in this field to make friends....;)

(Chuck Evans, CMI TREC 7657) #20

[quote="pabernathy, post:19, topic:80039"]

Really...on what planet?

I would expect that from an "Unregistered" response rather than someone who really knows me and knows what I say...but again I never cared to please everyone and never got in this field to make friends....;)
[/QUOTE]

Well I didn't feel condescended to. I did appreciate the comment about the garage ceiling outlets as I never knew the backstory to it. I find that most times there is a code item that makes no sense to me that it is probably there is something that I don't understand, yet.

I think that consolidating the gfci function in the main breaker for the distribution panel would lead to greater frequency of activations, broader disruption when they occur and would make it quite challenging to determine the component causing the activation. The next post will be why do I get so many nuisance trips???