We are being asked to test the existing bonding of a public pool. Is there a recommended procedure for this. We plan to connect a wire to the pump, stretch it out to each metal device (ladders, eyelets, etc) and record readings. In a preliminary run we had clean readings, but we also get near the same readings if we connect the megger leads directly into the earth. we don'yt trust these readings. Any suggestions?
here is what i did on a public pool.
it was a replaster job, and the city inspector wanted the *existing* wet niche shells REMOVED
from the side of the pool, so he could inspect the bonding. destroying them in the process.
the deck wasn't poured yet, so... i drove a ground rod in two places, did a cadwelded loop
all the way around the perimeter of the pool, then cadwelded the #6 tails from the five
existing wet niche shells to this wire, and finally, took a #6 over to the pool equipment area,
and bonded everything to it.
here is what i did that made the inspector go away happy:
the pool was full of water, so i taped a test probe to a stick of pvc plastic pipe,
clipped the other lead to the ground wire loop out in the dirt, and put 1,000 VDC
to the bezel of the light, and measured the voltage able to be maintained across
the ground.
as difference of potential is what is required for a shock hazard, i was measuring
if the pool water and ring had 1KV dropped on them, how much difference of potential
would there be between that, and the ground wire in the dirt. the fluke meter will
show the voltage between the test leads.
it showed 0.0 ohms, with 1 VDC between the test leads, so it would not be possible
for you to get shocked with 1KV in the water, grabbing a ground rod.
the inspector smiled, nodded, signed off on the final for the pool, and all was well.