[TowerTalk] [Grounding of tower

Jim W7RY w7ry at centurytel.net
Sat May 11 10:06:58 EDT 2013

On May 11, 2013, at 7:51 41AM, "K1TTT" <K1TTT at ARRL.NET> wrote:

> Consider this example... my neighbor had a broken ground in the wire
> overhead from the transformer to his entrance panel.  There are ground 
> rods
> at the pole and at his entrance as required.  When a big load on one side 
> of
> the line started, like a refrigerator, that leg browned out but the other
> leg of the 220 would get up to about 200v and blow out stuff on that 
> circuit
> due to the overvoltage.  Obviously there wasn't enough return current
> through the ground, even over that relatively short distance, to keep the
> supply balanced.

No... Your neighbor had a broken or high resistance NEUTRAL! A broken 
"ground" will not cause this!  This is a common phenomenon. When the air 120 
volt compressor starts in my shop/garage, the lights (read voltage goes up) 
get brighter on the other phase when the compressor starts.

That's because the neutral from the street pad mounted transformer is 
smaller than the 120 volt legs. This voltage drop in the neutral, un 
balances the voltage. I'm 175 feet from my transformer. It's very common to 
see this even with short length conductors from the distribution transformer 
to the service entrance.

Jim W7RY

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