Did a service call today on inground pool. Got in the water, touched the rim of the concrete on pool deck, got small shock. The pool is bonded correctly. I notice the more load I put on the house, the greater the shock was. I turned on both air conditioners, oven, and two cook tops and the shock got worse. When I turned the loads off, the shock almost went away. New subdivision with new transformer. I think the problem is the power company. Any ideas, please reply!
Inground pool small shock
- Thread starter domnic
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
domnic said:
Podco would be my first bet also. I would also check all bonding and grounding at the main service.
mdshunk
Senior Member
- Location
- Right here.
You might want to snap an amp clamp around the GEC at the service to see what you measure. The more marginal the neutral becomes, the more current (tries) to flow through the earth. That said, I'm not sure how any pool, when bonded correctly, could have a potential difference between the deck and the coping as you describe. When bonded properly, you should be a bird on a wire at that point.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
domnic said:
Did you actually get in the pool?
It does sound as though there is an issue with the unbalanced load current.
I second Marc's thoughts about a properly bonded pool as having a difference of potential between the pool and the coping.
electricalperson
Senior Member
- Location
- massachusetts
how close is the pool to the house?
does the bonding conductor go back to the panel?
does the bonding conductor go back to the panel?
pool
pool
Yes i got in the pool.the pool is 15' from the home. the transformer is 30' from the home. HO. SAY THEY HAD THIS PROBLEM FROM DAY ONE HOME IS TWO YEARS OLD.i got 1.5 volts from water to pool deck.with a 100 amp load on the home i got 3 volts.
pool
Yes i got in the pool.the pool is 15' from the home. the transformer is 30' from the home. HO. SAY THEY HAD THIS PROBLEM FROM DAY ONE HOME IS TWO YEARS OLD.i got 1.5 volts from water to pool deck.with a 100 amp load on the home i got 3 volts.
tonyou812
Senior Member
- Location
- North New Jersey
Man im itching to fix something like that, Its been pretty straight forward stuff for past few months......How come other people get the cool stuff.is that a metal pool?? did they miss the bond around the steps or something?
ayerforce
Member
- Location
- Hubertus, Wisconsin
- Occupation
- Electrical contractor
You mentioned that the shock potential increased after energizing what equates to a lot of line to line loads. How about the possibility of insulation failure in the branch circuit conductors serving the pool equipment? Try GFCI protection of those branch circuits at the service panel, if not existing. Just a thought. It's late and that's all I can come up with!!!
quogueelectric
Senior Member
- Location
- new york
Sounds like the primary current is increasing to ground. Think out of the box and think your pool is properly grounded and the stray current running across the coping is conducting to ground IE the pool. If the house load is increasing on both legs the neutral current shouldnt change but if the total load is increasing the primary current should be increaing proportionally. Do yourself a favor and dont voulenteer to go in the pool until it is fixed. I would check the pocos xformer neutral first. Primary that is.
quogueelectric
Senior Member
- Location
- new york
Just a quick note you have good troubleshooting skills even though you could have electrocuted yourself. I am serious though nice job just dont put yourself in the line of fire next time trust the person who is telling you they are getting a shock and use your tester to figure it out you will live a lot longer. Your troubleshooting flowchart shows me you have a great understanding of the circuitry though. Good Job!!domnic said:
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
080524-0817 EST
domnic:
See my probing measurements in post #12 at
http://forums.mikeholt.com/showthread.php?t=99809
The best reference point would be the grounding rod or equivalent at the residence.
You could do a rough voltage distribution map around the pool and yard. Also the voltage of the water. From this map you may be able to estimate the source of the current.
.
domnic:
See my probing measurements in post #12 at
http://forums.mikeholt.com/showthread.php?t=99809
The best reference point would be the grounding rod or equivalent at the residence.
You could do a rough voltage distribution map around the pool and yard. Also the voltage of the water. From this map you may be able to estimate the source of the current.
.
quogueelectric
Senior Member
- Location
- new york
Is this underground and is this the last xformer on the primary?domnic said:
quogueelectric
Senior Member
- Location
- new york
I would bet my left 2 hooves that this is primary neutral current grounding itself to your customers pool where it finds a better ground. If you put one lead of a tester right to the ground wire on the pool pump I will bet my tail also you will read a voltage gradient heading right to the xformer Where you should read your highest voltage to the pool ground wire. These power companys rarely admit guilt to anything so videotape your findings. Edit to say watch closely the voltage values as you aproach the xformer you dont want to exceed the limits of your tester. They tend to vaporize and arcflash over at a certain level.domnic said:
Last edited:
wirenut1980
Senior Member
- Location
- Plainfield, IN
It definately sounds like primary neutral return current. This could be from an overloaded single phase primary tap, or the tap is not well grounded enough, or there is high resistance from a bad connection somewhere on the primary neutral. But if everything is bonded correctly, there should be an equipotential plane and no potential difference should exist.
A couple options going forward:
1) Contact power company and see if they will do any testing on their system for excessive neutral voltage drop. If they do test and find something, there are steps they can take to correct, but they may not do anything.
2) Find out what what is not bonded causing the potential difference on the premises.
3) Have a ronk blocker installed near the transformer to block out utility neutral current.
A couple options going forward:
1) Contact power company and see if they will do any testing on their system for excessive neutral voltage drop. If they do test and find something, there are steps they can take to correct, but they may not do anything.
2) Find out what what is not bonded causing the potential difference on the premises.
3) Have a ronk blocker installed near the transformer to block out utility neutral current.
cadpoint
Senior Member
- Location
- Durham, NC
quogueelectric said:
I'm sorry I missed where your measuring too ... or the placement of the second needle ? ?
quogueelectric
Senior Member
- Location
- new york
The ground wire on the pump motor. MOO!!!!cadpoint said:
cadpoint
Senior Member
- Location
- Durham, NC
quogueelectric said:
OK, I like Ketchup and mustard too ...
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