[whiskey79]

Got a call from a pool guy I do a lot of work for the other day. Pool pump not working and people getting shocked by handrail. 240V subpanel was reading 120 to neutral and ground, 120 between legs. Sub-panel was fed with 10-3 uf and 1 hot leg and ground were cut and had continuity on sub-panel side of the cut.

When the 2 pole breaker for pool pump was closed voltage was feeding through motor to the cut hot leg and grounding conductor, which was energizing everything that was bonded. Pool guy said he measured between 12v and 25v between handrail and concrete and water which I believe could have been higher with the right circumstances. Seems like this was a case where bonding created a very dangerous situation. I corrected the problem by re-feeding sub-panel with #8 copper in 3/4" pvc with #10 ground in 120' trench.

 

[Dennis Alwon]

If the handrails and concrete were bonded properly then there should not be a voltage difference between the water and the concrete. The bonding should make all parts of the pool and equipment at the same potential so that you could not feel the voltage

 

[whiskey79]

I doubt a metal handrail and concrete deck have the same conductor properties, hence a difference in potential but not the full 120v.

 

[A Little Short]

I doubt a metal handrail and concrete deck have the same conductor properties, hence a difference in potential but not the full 120v.

If everything had been bonded you wouldn't even had the 12-25V that was measured. The voltage would still be there but there would be no potential difference to measure.

Sounds like you fixed the fault but that didn't take care of the lack of bonding which is why he measured voltage between the handrail and deck.

 

[whiskey79]

I know the handrail was bonded because the bond wire was visible and it passed through the concrete to get to it, so it seems like the concrete would be bonded at least in the general area of the handrail. What I'm thinking is that with two different types of material you could still have potential because of their conductor properties. I just don't see how running a copper wire around a pool deck bonds the entire concrete deck.

 

[chicken steve]

So just how would one test a pool bond ? :001_huh:
~CS~

 

[nrp3]

Somebody posted recently how they do it. Interesting read. I think thats something required in NJ for commercial pools.

 

[crazyboy]

Somebody posted recently how they do it. Interesting read. I think thats something required in NJ for commercial pools.

Yup, every 5 years it is required in NJ for all pools except for 1 and 2 family dwellings.

However, there is not specifics in the law. We typically do a visual inspection of all bonding points, replacing anything that is corroded. We then test between points with a microohmeter, and then hit it with a megger to make sure the connection will remain intact in a fault. We also keep a drawing with dimensions and measurements on file.

 

[denny3992]

Yup, every 5 years it is required in NJ for all pools except for 1 and 2 family dwellings.

However, there is not specifics in the law. We typically do a visual inspection of all bonding points, replacing anything that is corroded. We then test between points with a microohmeter, and then hit it with a megger to make sure the connection will remain intact in a fault. We also keep a drawing with dimensions and measurements on file.

No liability there right? I mean i hope i charge way more than u need to as some day ull be dragged into court to testify or defend...

 

[crazyboy]

No liability there right? I mean i hope i charge way more than u need to as some day ull be dragged into court to testify or defend...

I'm not the owner....but going rate on this is very far from cheap.

 

[robnj772]

I'm not the owner....but going rate on this is very far from cheap.

You have to carry extra insurance for that to actually legally do it .

Your boss probably doesn't and hasn't been called out on it.

 

[hardworkingstiff]

You have to carry extra insurance for that to actually legally do it .

Is that in the state statutes?

 

[chicken steve]

I guess we have to give NJ the nod for preventative maintenance here...:thumbsup: ~CS~

 

[nrp3]

Unfortunately, as often the case, someone died for this to come about. Not sure I want to tackle that job.

 

[chicken steve]

Agreed mortality and liability are two issues on one job most of us don't need nrp3


~CS~

 

[krisinjersey]

I've offered this service for about 10 years here in New Jersey. We provide an annual visual inspection of the bonding system. I check all the connections on the equipment pad, pumps that may have been taken out of service and reinstalled for instance. We also inspect the deck for maintenance that could have damaged the bonding systems. I've seen a pipe leak repair cut the bond to 3/4 of the pool. We also use a ground resistance tester to test the connection between the points we can visually inspect (ladder cups).
Every 5 years we do a functional inspection. We have a digital drawing of the pool showing each bonding point. We then use an AEMC ground resistance tester to test from point to point and record the test results into an excel spread sheet. This test, coupled with my annual, allows me to be somewhat predictive with bonding points failing. So I can let he pool owner know that the trend for a given ladder cup has been degrading, so we should replace it at the end of the season, not a week before Memorial Day. The issue with a municipal pool can be, if a bonding test fails, the pool is closed until the repairs are made and the test is redone and passed.
We give the customer a packet with the pool drawing, the test results and (2) certificates of the function of the bonding grid. We do have to pull a permit and we don't test on a pool that has anyone in it. We did add it to our liability insurance, but it didn't change our cost for insurance. We offer (2) different packages for customers, individual 5 year certifications and 5 year packages including the 4 off year annual inspections. We do qualify the certificates with a disclaimer stating that any disturbance to the pool structure will invalidate the test and certification. It's been a good way for us to make some solid money providing a valuable service with no heavy labor.



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[robnj772]

Is that in the state statutes?

No but the liability insurance we carry says right on it that commercial pool wiring isn't covered.

 

[Dennis Alwon]

I've offered this service for about 10 years here in New Jersey. We provide an annual visual inspection of the bonding system. I check all the connections on the equipment pad, pumps that may have been taken out of service and reinstalled for instance. We also inspect the deck for maintenance that could have damaged the bonding systems. I've seen a pipe leak repair cut the bond to 3/4 of the pool. We also use a ground resistance tester to test the connection between the points we can visually inspect (ladder cups).
Every 5 years we do a functional inspection. We have a digital drawing of the pool showing each bonding point. We then use an AEMC ground resistance tester to test from point to point and record the test results into an excel spread sheet. This test, coupled with my annual, allows me to be somewhat predictive with bonding points failing. So I can let he pool owner know that the trend for a given ladder cup has been degrading, so we should replace it at the end of the season, not a week before Memorial Day. The issue with a municipal pool can be, if a bonding test fails, the pool is closed until the repairs are made and the test is redone and passed.
We give the customer a packet with the pool drawing, the test results and (2) certificates of the function of the bonding grid. We do have to pull a permit and we don't test on a pool that has anyone in it. We did add it to our liability insurance, but it didn't change our cost for insurance. We offer (2) different packages for customers, individual 5 year certifications and 5 year packages including the 4 off year annual inspections. We do qualify the certificates with a disclaimer stating that any disturbance to the pool structure will invalidate the test and certification. It's been a good way for us to make some solid money providing a valuable service with no heavy labor.

So how are you testing the equipotential bonding other than a visual inspection. How would you know if there is a perimeter bond? or whether the connectors are made well or legally

 

[krisinjersey]

The ground resistance tester measures point to point resistance and ultimately the integrity of the bonding system. The certification is based upon the theory that during the initial construction of the pool, all components were bonded. If they were not bonded, the resistance is well over a megohm and considered to have either failed or never have been connected. Once the ladder cup is in the concrete, the connection will eventually fail. The test is there to catch it before someone gets hurt. We all know how varied the perimeter bonding has been over just the last few code cycles, so the rebar isn't tested. The test is there to keep bad connections from failing and becoming a hazard and forcing a repair prior to opening the pool.


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[Dennis Alwon]

Sorry I missed the ground resistance tester- sometimes I skim too much when I read.