14 Feb
2002
14 Feb
'02
8:31 a.m.
Okay guys, this is from my wife, who works for Hubbell
Wiring
Devices...
:-)
--- David A Woyciesjes
--- C & IS Support Specialist
--- Yale University Press
--- mailto:david.woyciesjes@yale.edu
--- (203) 432-0953
--- ICQ # - 90581
Mac OS X 10.1.2 - Darwin Kernel Version 5.2: Fri Dec 7 21:39:35 PST
2001 Running since 01/22/2002 without a crash
Nearly it. The neutral is where the nasty surges come in on, as there
should be no current on the ground unless something has failed. You will,
however, get ground loops with the `standard' grounding system. Because it
is designed to show a low impedance to fault currents and catch many
different kinds of faults, it is bonded to just about every piece of metal
in the building (including the gas line in the 2002 Code!)
No one asked me about the Technical Power transformer, I thought people
would be more interested in that. Since nobody is asking, I'll just have
to volunteer-- it's a 120v isolation transformer, with a grounded center
tap, -60, 0, 60. Pretty nifty, and only slightly illegal for residential
use. Make sure you don't have any ground faults before you plug soething
in! ^_^
Bob
----------
From: Theresa Woyciesjes
The green dot is the marking that UL allows manufacturers to use on
Hospital Grade devices only after the product has been tested and
performs to the UL specs for Hospital grade.
The Isolated Ground triangle is a designation
that is required by UL
and C.S.A. (Canadian Standards Ass.) to mark Isolated Ground outlets.
Orange may be the most popular color for the receptacle, but it is not
considered to be a clear enough marking for UL & C.S.A. The outline
of the triangle does not have to be any specific color, only easily
recognizable. The interior of the Triangle must be orange.
Hospital Grade IG receptacles will have both the green dot and the
triangle.
BTW - The reason someone may want IG receptacles in their home is to
protect the ground - you know that computers use the zero ground as the
reference for binary code - well, if you are running your computer and
your wife turns on the vacuum or the blender, the motor load can throw
noise onto the ground - causing your computer to read a 0 as a 1. If
you have your computer plugged into a IG receptacle that is properly
installed with it's own ground wire, the interference caused by the
motor load will go out on the house grounding system with out
effecting your PC. >
>
>
> Theresa - Ann Woyciesjes
> Hubbell Wiring Device - Kellems
> National & Strategic Accounts
>
>