GFCI Protecting Entire Pool Panelboard then use standard breakers?

macmikeman

Senior Member
Interesting that we have to worry so much about the pools, which is proper, don't get me wrong.
I just find it interesting because in my experience, most pool installing companies don't give a rat, and usually
don't even get an electrician or a permit unless the pool is going in as part of a brand new house build. At least that is how around here...........
 

kwired

Electron manager
Location
NE Nebraska
Interesting that we have to worry so much about the pools, which is proper, don't get me wrong.
I just find it interesting because in my experience, most pool installing companies don't give a rat, and usually
don't even get an electrician or a permit unless the pool is going in as part of a brand new house build. At least that is how around here...........
I'm sure this varies based on location and how the AHJ's operate.

Here if you putting in a pool at a dwelling, you probably don't need to file electrical permit, unless you end up making changes to the service equipment. You may or may not need building/zoning permits to build the pool though, but out here in the boonies we only have state electric inspectors. In cities that have local electric inspectors, you likely get an electric inspection of that pool and they will know about it unless all permits were ignored, then they come and cease operations if they discover it being done with no permits. Probably not as easy to get away with unless on very large property where they can't observe what might be going on too easily. Need to upgrade utilities possibly triggers things as well, even if not the municipal utilities.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
However, it's possible that deteriorating conditions could cause the leakage on each phase of a 2-pole GFCI breaker to slowly creep up over time so that the leakages match each other closely enough that the breaker doesn't trip. These leakages could be from L1 to L2 through the pool. Or one phase could have leakage to the EGC or the earth, and the other phase have leakage to the pool.
I'm thinking about this. :unsure:

This isn't the same as a balanced MWBC. If the water becomes energized, even if the two leakages are equal, there should still be current flowing into the earth that is not returning on the neutral. I think it would behave like two individual circuits.

Opinions welcome.
 

kwired

Electron manager
Location
NE Nebraska
I'm thinking about this. :unsure:

This isn't the same as a balanced MWBC. If the water becomes energized, even if the two leakages are equal, there should still be current flowing into the earth that is not returning on the neutral. I think it would behave like two individual circuits.

Opinions welcome.
Equal down to 4-6 mA and less is not going to be easy to maintain I would think, majority of time enough leakage to ground is probably occurring that it trips the GFCI.

Take two identical 120 volt loads and connect them in MWBC configuration, I bet you find at least 6 mA or more current on the neutral in a lot of instances. Maybe some more precision electronic loads will be more exact, but a typical resistance load probably has enough tolerance level it won't be that exact each time.

Then you still may have slightly different line to neutral voltage on each line to cause a differential even if the loads were precisely the same resistance.
 

SSDriver

Senior Member
Location
California
Occupation
Electrician
The most important thing is the exponential bonding. 80% of my work is on commercial pools and 95% of those motors are not GFCI protected and 3 phase. I have changed out 1000's of motors that have burned up for different reasons. I haven't seen any issues with voltage in the water that weren't caused by pool lights not on GFCI circuits.

A GFCI main breaker might be fine for a simple pool with one or two pumps, 2 lights and that's about it. On bigger systems it will be an issue. On commercial pools they definitely wouldn't go for a bad pool light stopping their circulation pump and closing the pool. Residential pool guys would also be pissed that a gfci tripped from the light now tripped the pump and chlorine feeder allowing the pool to go green in a few days. Having separate GFCIs for each branch circuit is definitely the way to go.

Homeowner probably won't be happy that they can't heat there spa because of a bad pool light or landscape lighting
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
However, it's possible that deteriorating conditions could cause the leakage on each phase of a 2-pole GFCI breaker to slowly creep up over time so that the leakages match each other closely enough that the breaker doesn't trip. These leakages could be from L1 to L2 through the pool. Or one phase could have leakage to the EGC or the earth, and the other phase have leakage to the pool.
I'm thinking about this. :unsure:

This isn't the same as a balanced MWBC. If the water becomes energized, even if the two leakages are equal, there should still be current flowing into the earth that is not returning on the neutral. I think it would behave like two individual circuits.
...
I agree with your statement in bold above. However, to illustrate a point consider the following examples of leakage at outputs L1 and L2 of a 2-pole GFCI breaker with a load neutral N:

1. 12 mA from L1 to pool water, 9 mA from L2 to pool water.
2. 12 mA from L1 to pool water, 9 mA from L2 to EGC
3. 12 mA from L1 to pool water, 9 mA from L2 to earth
4. 12 mA from L1 to earth, 9 mA from L2 to earth

In none of these cases is any leakage current flowing through the load neutral.
The leakage current from L1 to the pool water could return on L2, the EGC, earth and GES, or a combination of thereof.
The leakage current from L2 to the pool water could return on L1, the EGC, earth and GES, or a combination of thereof.
But in all of these cases the amount of common mode current through L1, L2, and N (i.e., the RMS value of their vector sum) is 12 mA - 9 mA = 3 mA, and this is what the current transformer inside of the GFCI responds to. Therefore the GFCI will not trip while under these leakage conditions.
It is true that any current flowing out of the GFCI (including any leakage) must match the current returning to its output terminals within less than 6 mA , or the GFCI will trip ( 4 mA or less to guarantee that it won't trip) . The neutral is not necessarily involved in this if there's a 2-pole breaker, but it would be involved if there was a ground fault on the neutral.

For simplicity I'm assuming that all leakage currents are in-phase with their associated applied voltage, or they're at the same phase shift.
 

rnatalie

Senior Member
Location
Catawba, NC
Occupation
Retired Electrical Engineer
Interesting that we have to worry so much about the pools, which is proper, don't get me wrong.
I just find it interesting because in my experience, most pool installing companies don't give a rat, and usually
don't even get an electrician or a permit unless the pool is going in as part of a brand new house build. At least that is how around here...........
Which is why we are still losing a person or two a year to poorly installed pool lighting.
 

kwired

Electron manager
Location
NE Nebraska
Which is why we are still losing a person or two a year to poorly installed pool lighting.
Quite honestly if I were to have a pool installed, I have no desire to put lights in it. Something with optical fiber to a remote light source maybe would be a consideration, but still why do you need lights in a pool to begin with?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Quite honestly if I were to have a pool installed, I have no desire to put lights in it. Something with optical fiber to a remote light source maybe would be a consideration, but still why do you need lights in a pool to begin with?

Yeah. there is no reason for lights

 

hillbilly1

Senior Member
Location
Atlanta,Ga
Occupation
Field coordinator/ technical support
As I said, current could leak from one branch circuit conductor to another through the pool water and you and not trip a GFCI only on the feeder.
Sure, but unless for some strange reason somebody is between the two hots, they would have to be insulated, no shock would be possible. If somebody touches it and ground, GFCI will trip regardless of which hot is touched. But as someone else has probably already said, the cumulative leakage current on all circuits would probably cause nuisance tripping.
 

brantmacga

Señor Member
Location
Georgia
Occupation
Electrical Monke
Quite honestly if I were to have a pool installed, I have no desire to put lights in it. Something with optical fiber to a remote light source maybe would be a consideration, but still why do you need lights in a pool to begin with?
I have a pool, and there’s no way I wouldn’t have lights in it.

I have installed some of the optical fiber lighting, but it takes more of them I think to get equal output of a nice pool light. It’s been years since I’ve installed one though, so maybe they’ve improved?


Sent from my iPhone using Tapatalk
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
It would be a great experience for an accomplished diver when they had to come get me from a panic attack!!!
That's why proper training is so important. When you instinctively know how to handle an issue, the tendency to panic is greatly reduced. I have cave dived. That's one place you can't lose your cool, where you might have to go down to go up.

Side story: when I was a young teen at summer camp, where I first took diving lessons, one of our first tasks was to see how far we could get assembling a series of pipe nipples, reducing couplings, and end caps, 2" down to 1/2", on one breath.

I always got a full assembly because I only threaded each joint about one turn, and then twisted all the parts tighter by just turning the end caps with whatever breath I had left.

I still tighten straight runs of RGS as a whole, like to avoid having to loosen a joint to get an elbow or fitting to point the right way.
 

TheGingerElectrician

Master Electrician Electrical Contractor, TN
Location
Tennessee
Occupation
Electrical Contractor
Thanks for the help guys! I understand and agree with everyone who has an issue with narrowing down any ground fault issues when the whole panel is gfci protected. Its all about what is available. I can't even get square D stuff here right now. It makes sense to gfci protect the whole panel for all the 240v stuff and then add 120v branch cicircuit gfci breakers where required at this point.
 

Mystic Pools

Senior Member
Location
Park Ridge, NJ
Occupation
Swimming Pool Contractor
Interesting that we have to worry so much about the pools, which is proper, don't get me wrong.
I just find it interesting because in my experience, most pool installing companies don't give a rat, and usually
don't even get an electrician or a permit unless the pool is going in as part of a brand new house build. At least that is how around here...........
Damn pool guys!!:D
 
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