-- The air conditioner made a horrible clacking noise
-- All the light bulbs in the house went to an amazing brilliance
-- There was a loud buzzing noise (60 Hz) from inside the house
-- The VCR blew up.
All this in five seconds.
I pulled the block out and the above phenomena stopped over the next few seconds (except for the VCR, an instantaneous event).
Turns out the underground neutral from house to streetside junction box had failed. PEPCO (Potomac Electric Power Co.) ran a copper wire along the surface until the could bring in a backhoe and relay the feeder. Ultimately the whole house had to be rewired as it had poltergeist effects for some time after.
Carleton
In a message dated 2003-01-25 01:09:01 Eastern Standard Time, [EMAIL PROTECTED] writes:
2003-01-25
In addition, a copper wire is run from the fuse box neutral post to the
water pipe inside the house. At least here in Cleveland it is. Some years
ago, the neighbour next door experienced the very thing you spoke of. The
neighbour lady called me over to have me check to see why her appliances and
lights were acting funny. I discovered the line was not balanced. The
voltage from one side to neutral was low and the other side to neutral was
high.
I pulled the main fuse out to prevent damage to her appliances. I
discovered that the ground wire connecting the neutral tap of the fuse box
to the water pipe was missing. I had some 10 ga wire and a spare water pipe
ground terminal at home. I connected the wire from the cold water pipe to
the neutral tap. I plugged the fuses back in and checked the voltages and
the balance had been restored.
I was surprised the ground wire had been missing, but there was nothing that
could have been done since it was that way for over 30 years. I told her to
call the power company to see why the neutral was lost from the pole to the
house. It turned out that the incoming neutral line had broke. In our
neighbourhood, the neutral line is not insulated and the two insulated hot
lines are wrapped around the neutral line (braided). Somehow, from who
knows what, the wire just broke. The power company just spliced the neutral
line back together. And everything was fine again.
But, this made me think. With the ground wire missing from the water pipe
to the neutral bar, she knew right away there was a problem. If the wire
had been there, she may have never known that her neutral line was open
coming from the pole. Relying on the water pipe to balance the load may
cause a situation you mentioned with the cows. If the voltage drop from the
water pipe to the transformer centre tap was a few volts above true ground,
someone could possibly experience a shock when they touched the water pipe
near the point where the ground tap is mounted. I wonder which is better to
be grounded to the water pipe or not.
Sounds like a no win situation.
John
