troubleshoot

[boltneck]

customer has experienced slight shock at times in the shower

checked between drain and shower head- around 8-10 volts
not phantom, does not change when checked with a solenoid tester

turned off main, voltage goes away

as the 2 pole radiant and baseboard heat circuits are turned on, there are 4 circuits that translate into around 2-3 volts at the shower when each are turned on
when all the heat circuits are on, it adds up to around 8-10 volts

no other circuits in the house have any effect on the shower

should I open the wall and just bond the drain to the showerhead?

 

[GoldDigger]

A solid 8-10 volts sounds more like a high resistance neutral forcing load current to flow through a high resistance EGC instead.
I would find the cause of the potential instead of just adding bonding. The risk seems to me to be too great to do anything else.
YMMV.

Tapatalk!

 

[zbang]

should I open the wall and just bond the drain to the showerhead?

Are the plumbing system(s) metal or plastic? If the line to the shower head is all plastic, you shouldn't see any current at all. Could be mixed metal/plastic and no bonding jumpers across the plastic parts.

Also, you mention 2-pole heaters, which I assume then are connected line to line. Turning those on/off normally shouldn't affect a loose or high-resistance neutral connection, but if one of them has a ground part way across the element it could. Have you megger'd them?

 

[boltneck]

didn't have time to troubleshoot any further

if it were only one heat circuit that caused the voltage we would have dug deeper, broke the circuit apart and megged

the fact that 4 different circuit added a few volts had me puzzled

copper pipes, not sure about the drain, its an older house, I assume copper

 

[GoldDigger]

In an older house the immediate drain fitting might be brass, but the pipe would be a mixture of steel and cast iron, IMHO.
My decision on what to do what also depend on whether the stray voltage relative to a remote ground was on the shower head or the drain.
Leakage from a sub floor radiant heater, for example, could be energizing a conductive concrete or mortar floor or tile bed. That voltage could then transfer to a metal drain fitting which is not grounded because of a plastic pipe section.

Tapatalk!

 

[cadpoint]

...as the 2 pole radiant and baseboard heat circuits are turned on, there are 4 circuits that translate into around 2-3 volts at the shower when each are turned on.

So it's 4 set of two pole breakers? Just checking... My guess is all these circuits are run in the same bored hole and one nail got all four. What are the odds of that?

It stuck in my mind about parellal and series circuits... whatever...

Did you measure voltage on the individual grounds of each circuit?

You sure they didn't redo the bath area or a pipe on the water or drainage lines and will not confess that they toasted some wires?

You could test each circuit with a two pole AFCI or meggaring is should be the same result.

The problem is isolating where these two things are touching...

This is one of those fifty questions moments, it's a case and effect that you need to qualify
and resolve. Easy to resolve from the arm chair!

Good Luck, Happy Hunting!

 

[boltneck]

Thanks, I will post more info if we go back

yes, it is 4 different 2p20 heat circuits in different areas of the house. Some are radiant heat imbedded in the ceiling plaster, and at least one of the circuits is a baseboard heater circuit in the basement that I could visually follow the wiring.

As each breaker is turned on we got 2-3 volts between the drain and the shower head

I didn't check from a remote ground if the voltage was on the drain or shower head, I should start there

 

[San -Brooke]

If it is an old house it should be copper water line, you should have the water line bonded for no other reason than to provide an easier path to ground than from showerhead to drain.

 

[paul]

If I were to guess, the voltage most likely is coming from the drain. Believe it or not, the first place I would look would be in the attic space. Check for blown in insulation and knob and tube wiring running close to the cast iron vent pipe. I have seen a couple of similar situations. I cleared the area of the insulation and then bonded the drains the same as I would bond the water pipe with some #4.

Check with a known ground and verify that the voltage is indeed coming from the drain or the water pipe. Then go from there.

Goodluck

 

[cowboyjwc]

You probably have a loose neutral at the weather head or some where else. Something is grounding out, but not enough to trip the OCPD, just trickle to ground.

 

[cowboyjwc]

So I guess we're never gonna find out what was wrong.:?

 

[boltneck]

So I guess we're never gonna find out what was wrong.:?

They haven't called back yet. We were only there to install a dryer ckt. Additional work wasn't on the ticket

Looked at it just enough to determine what was posted and told customer we needed to troubleshoot further

I will reply if we go back

 

[cowboyjwc]

Wow, you would think they would be concerned.