[TowerTalk] Resistance in house neutral

[Jim Brown]

On Tue, 27 Jul 2010 07:00:43 -0400, Pete Smith wrote:

>Thanks for this and other pointers, Jim.  I have an outlet tester by 
>A.W. Sperry Instruments that seems to cover a lot of "ground" .  It 
>puzzles me that it has an indication that it says reflects "open ground" 
>- I wouldn't think you could see actual ground anywhere but at the 
>breaker panel.

The "ground" they're talking about is the green wire between the outlet and 
the breaker panel. That suggests there is a problem with wiring to that 
outlet, specifically an open green wire. 

OR -- it might be neutral and ground reversed at the outlet, which is a 
common, and very nasty, wiring error. I would definitely pursue that.  

Yes, 4mV is quite low. On the other hand, if there is no current on any 
wiring on the circuit that feeds that outlet, and if the outlet backbox is 
not grounded, that may not indicate a problem. Under the condition I've 
described, the only AC voltage should be due to magnetic induction from 
nearby currents, or noise. 

73, Jim K9YC