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From: tonya@hpldsla.sid.hp.com (Tony Arnerich)
Newsgroups: sci.electronics
Subject: Re: What's acceptable voltage ground-neutral?
Message-ID: <1990016@hpldsla.sid.hp.com>
Date: 16 Apr 91 20:19:39 GMT
References: <1991Apr13.131621.225@mandata@uunet.uu.net>
Organization: HP Scientific Instruments Division - Palo Alto, CA
Lines: 21

I've often seen around 4V GND-NEUTRAL at work - that got me a bit worried.
Too much use of extension cords is the typical cause. It seems that about
1 in 10 people don't get the message...

If you know the current that corresponds to a particular voltage drop, you
can get the wiring resistance.

If you get anything over a couple of volts, you might try making
the same measurement at your electric panel to see where the voltage
drop is occuring:

A) If it's in your part of the wiring, you might have a high-resistance
   connection at a receptacle. This could be a fire hazard (Remember when
   some builders buried aluminum wiring inside house walls?).

B) If it's in the power company's wiring, don't worry about burning
   down your house, but shock hazards can still be a threat. Just think
   about all those polarized plugs that make you believe you'll only get
   exposed to "0V".

tonya@sid.hp.com