Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!mcnc!unccvax!dya
From: dya@unccvax.UUCP (York David Anthony @ WKTD, Wilmington, NC)
Newsgroups: sci.electronics
Subject: Re: How can I recognize true ground?
Message-ID: <1550@unccvax.UUCP>
Date: 10 Jul 89 14:07:09 GMT
References: <18425@mimsy.UUCP> <1989Jul7.155721.19105@utzoo.uucp> <18447@mimsy.UUCP>
Organization: Univ. of NC at Charlotte, Charlotte, NC
Lines: 23

In article <18447@mimsy.UUCP>, spector@brillig.umd.edu (Lee Spector) writes:
> I asked how to tell if a house outlet is properly grounded...
> 
> MANY THANKS to all respondants!  I've received about 8 email answers
> already!  It turns out that about half of the outlets in my house are
> properly grounded...  I found out using one of those "3 LED outlet-testing
> gizmos".  Thanks again.  -Lee

	The three-LED outlet testing gizmo does **NOT** verify the most important
aspect of a proper safety ground, namely, that it can carry the **entire** fault
current between the "hot" leg and the safety ground.

	While the device provides a "no-go" indication of improper wiring (say,
hot and neutral interchanged, ground definitely open, neutral definitely open
or no power) it does not verify the fault current handling capability of the
ground wire.

	I personally would not stake my life (or any equipment worth more than
a nominal sum, say < $ 500) on a tester such as this. How high does the resistance
in the ground leg have to be before the LED fails to light ????

York David Anthony
WKTD Wilmington, NC