Eq Pot Bond at Pool

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augie47

augie47

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State Electrical Inspector (Retired)
Have an electrician evaluating a pool shock complaint. Measuing 1-5 volts to gound on railings; Checking continuity from the handrail to the EQPB conductor at the pool pump reads 90 ohms. The pool is an older install and my thinking is along the lines of corrision at the hand rail fittings. Is rhat a reasonable possibilityy ? If there bonding did not reach the hand rail originally could you reasonably have a 90 ohm reading ??
(Homeowner reports still getting a shock with the house main "OFF" but there are 500k transmission lines in the vicinity)
 
There is a 2 to 3 volt measurement from earth (dirt) to the grounding electrode conductor at the house and the same at the POCO pole.
They came to site and advised no problem on their end.
 
augie47 said:
There is a 2 to 3 volt measurement from earth (dirt) to the grounding electrode conductor at the house and the same at the POCO pole.
They came to site and advised no problem on their end.
Click to expand...
That is pretty common where the utility connects their transformers line to neutral, and is a measurement of the voltage drop on the primary neutral. You should get that same voltage between the dirt and all of the conductive parts of the pool and that is ok. Where you have a higher voltage between the pool parts and the dirt there is a problem. Also you can have a problem where parts of the pool are at a different voltage than other parts.
 
If when they turned off the main power to the house. If some how you could also disconnect the main neutral. That would eliminate quite a bit of trouble shooting.
You know what I am getting at. Perhaps the pool bonding is a better ground then the neighbors utilities neutral.

If they're still getting shocked you might have to disconnect the phone , cable and internet grounding. As you know they're all connected indirectly to the pool EBP
 
augie47 said:
Have an electrician evaluating a pool shock complaint. Measuing 1-5 volts to gound on railings; Checking continuity from the handrail to the EQPB conductor at the pool pump reads 90 ohms. The pool is an older install and my thinking is along the lines of corrision at the hand rail fittings. Is rhat a reasonable possibilityy ? If there bonding did not reach the hand rail originally could you reasonably have a 90 ohm reading ??
(Homeowner reports still getting a shock with the house main "OFF" but there are 500k transmission lines in the vicinity)
Click to expand...
It's most likely the rail escutcheons. Most are aluminum and they don't rust, they just crumble. The bond screw on the bottom then fails. Bronze escutcheons will last longer.
 
I checked a pool a couple of years ago according to the method Mike Holt showed on his video. Found the remote earth voltage and checked everything against that. I found that I had lost part, if not all the bond at the handrail. Funny thing is this pool was right next to transmission lines too. Anyway, as a temp fix, I ran a bare #8 on top of the ground from the bond going to the pump motor and over to the handrail. I then went from one rail to the other to make sure there would be no potential from one to the other. For good measure, I also ran a tail off the handrail bond into the water. That took away the shock/voltage.

I figured since one of the rails had good continuity to the grid and the ladder also had good continuity, that the pool was bonded properly except at the handrail. I figured the escutcheon was bad under the concrete. My temp fix was just to stop the shock so they could use the pool. They were going to have the deck cut and new plastic hand rails installed soon so I didn't take it any further.
So @augie47, you're on the right track with the handrails.
 
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