dpb wrote:

Stormin Mormon wrote:
...

They built a mess hall, cabins, and a couple shower and toilet
buildings. Cement slab, wood frame walls. Shingled roof.

The campers are complaining that when they touch the shower
handle, they can feel an electrical tingle. The WH is propane gas
fired. The propane line (black iron) also goes to a Rheem Contour
furnace, which supplies an overhead heat duct.

I took a VOM and length of copper pipe, used that to check from
the shower handle to the drain. Got 5 volts AC. Doesn't happen
when the power is switched off for the furnace.

I traced the wiring, the furnace was only put in a year or two
ago. (Nobody complained about shocks until the new furnace was
put in.) New, shiny copper wires. I pulled the wire nuts on the
neutral and ground. The wires are clean, adequately stripped
back, and the wire nuts get a good "bite". The panel box, like
the rest of the building is only two or three years old, and nice
and new.

The WH has dielectric thread connections at the top, I can see
the red plastic at the fitting. From what I can tell, the water
main coming out of the ground is plastic.

The questions a

1) Why would a brand new furnace be leaking power? And how's it
getting into the shower? The only other electrical devices in the
building are lights, and a couple electric sockets.

2) Why isn't the power going out the neutral and ground?

3) How to safely take care of the problem so the campers aren't
being shocked?

My thoughts at the moment, are that the neutral / ground has some
corrosion or resistance past the panel. Meaning outside the
building. And that the solution is to run a new ground wire out
the wall, and sink a ground stake right outside the wall with the
panel box. Any other thoughts of how to handle this shocking
problem?


You have, almost certainly, a grounding issue. My first thought w/
separate buildings an auxiliary ground is inadequate/missing, but with
only a general description not possible to tell much specific.

If the plumbing is accessable it'd probably be wise to bond the water
supply pipes to the shower valve to the drain pipe before letting anyone
use the shower again, then do the overall grounding job properly ASAP.

I'm no lawyer, and never even played one on TV, but since you've told
the world about your knowing about this problem in a format which will
take forever to disappear, you'd best be carefull lest someone slips in
the shower, breaks their spinal column and then decides to go after the
cchurch for all it's worth, claiming that "the shock" made them jerk and
fall.

Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.


Need to know how the power is distributed and where the ground(s) are.
I'd be a little concerned that your measurement of the voltage is an
underestimate from the technique to reach so I'd treat this as a
potentially (pun not intended) serious issue. Probably adding a ground
directly at the shower head as a temporary pallative would help. Surely
there's a good electrician-type in the church that
can help diagnose this? Distributed system grounds can be very
difficult to trace and a pro should be able to recognize where there's a
problem if a needed ground is missing.

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