sorethumb

Hi

Anyone have a clue about this?

With the main breaker OFF the power coming into the house on the two leads from the outside meter reads 127 volts. When testing I switch between the ground in the circuit box and a nearby gas pipe for the ground lead for the meter. As soon as I apply a load, 150 watt lamp, the voltage on the burdened lead drops to 106 volts and the unburdened increases to 137. The problem reverses if I switch to the other incoming lead.

I first thought it was a ground problem but switching from well water pipe to gas pipe doesn’t help. Could the problem be outside the house? If I call the power company I need to know how to explain the problem or they will insist I call an electrician first. The electrician will not touch anything after the meter so I would like to get a feel for what is going on before I pick up a telephone.

sorethumb

Hi
I fixed it - it was a bad ground. The original ground wire to the well pipe had increased resistance due to corrosion. Apparently the gas pipe is not a good ground either. When I used auto jumper cables to the city water line the problem was solved.

It is hard to believe that before I discovered the bad ground I put a heavy load on the left side of the box. Left side voltage dropped to 16 volts. Right side voltage went up to 220V with the work light attached to that side burning super bright.

Lesson learned: output is as important as input

speedy petey

YOU DID NOT FIX THIS!!!!!!

You put a VERY dangerous band-aid on it!

You likely have a broken service neutral and by grounding the service better to the water pipe you created a path for the current to go.
The gas pipe ground is even worse! Gas piping is NOT(!!!) meant to be used as a grounding electrode.

Call the POCO first to check their side of the service drop. Then call a qualified electrician out to check this problem IMMEDIATELY!!

Parrothead

Exactly. When testing things like this, it is as important to test between ALL the conductors-Hot to hot, each hot to neutral, and each hot to ground. Hot to hot should read 240V, everything else 120. If ANYTHING is out of whack, you need to get a professional in there to fix it. Some things shouldn't be messed with by the homeowner.

sorethumb

Hi Speedy

Thank you for taking the time to set me straight. I thought I had fixed it by hooking up a better ground line because corrosion on the well pipe had reduced its grounding ability.

The ground bar in the box has a (approximately) ten gague copper wire running to the well pipe which is gavanized iron. I thought that was the service ground line. The house, which luckily is vacant, is about 120 years old. There is no copper rod in the ground outside the house as I have in another house that is only 60 years old. That why I figured the copper city water pipe was a fix. The only wires coming into the house from the meter are two hot leads which test 220v across.


Thanks again for the warning.

sorethumb

P.S and thanks again for the warning for anyone else who follows this thread later in the archives.