High impedance neutral?

CaliforniaMikeH said:
Current to the cable shield went from 2.5 Amps to 0.1 Amps.
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In the 20/20 hindsight department, I just realized that the POCO was probably doing their voltage tests with the CATV line in place, and since the CATV shield was acting as a back-up neutral it was limiting the voltage deviation. I've you'd pulled the CATV line before they did their testing, they might have seen the problem sooner.

Glad it all got figured out after the aggravation....
 
Yeah, one more observation RE the internet cable bond to ground...

On two occasions, they disconnected the cable shield bond to ground and then left it floating when they were done.

I have to admit that this did eliminate the neutral current on the cable ground...

Unfortunately, this did not actually address the issue, and my understanding is that this is a code violation.

Thanks again all!
 
ptonsparky said:
Anybody with a good meter and a hair dryer or two can locate a bad neutral.
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Yes, I haven't seen anything stating OP intentionally loaded up the neutral enough to get reliable information on whether it is compromised or not. Need to put some significant load on the neutral and see how line to neutral voltages respond to it. Doesn't need to be extreme load, hair dryer is usually sufficient. Let it run for several minutes to see if something heats up and then changes resistance over a little time. If you only see change of a tenth of a volt or two neutral may be fine. Change of couple volts or so - undersized or excessive length conductors could do that even though connections are all good. Some line to line loading and measurements can possibly help with further diagnosis of that situation.
 
CaliforniaMikeH said:
Yeah, one more observation RE the internet cable bond to ground...

On two occasions, they disconnected the cable shield bond to ground and then left it floating when they were done.

I have to admit that this did eliminate the neutral current on the cable ground...

Unfortunately, this did not actually address the issue, and my understanding is that this is a code violation.

Thanks again all!
Click to expand...
It is supposed to be bonded so there won't be voltage potential between them. Thing is that does create parallel paths and current takes all paths not just path of least resistance like many tend to say. Current in each path will be proportional to the resistance of that path, Ohm's law still applies. That considered I didn't think the current you measured back in OP was all that high. If you measured say 10 amps on the cable shield I would expect there to maybe be a more serious neutral problem.
 
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