Welcome to ECN Tesla, [Linked Image] I should have said that earlier.

by Tesla
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Ryan_J: That is code truth.... In my work, commercial, the AHJ has no problem with it. I, myself, cannot imagine how even a tyro is going to foul up such an install....

Tesla you have to remember this forum has members from all the country (and beyond) to give a recommendation based on what your AHJ allows will not help anyone outside your area. The wording from 250.119(B) certainly leaves it open to the AHJ.

part of 250.119(B)
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Where the conditions of maintenance and supervision ensure that only qualified persons service the installation,.....

The opening poster describes a wood framed bank, In my opinion an AHJ could feel this building does not meet 250.119(B)

by Tesla
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Roger: I agree entirely. IG receptacles don't get you anything in a residential application.

I also agree but Roger was not talking about a residential application. [Linked Image]

by trekkie76
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the receps are for computer equipment in a rewire of an existing bank. Specs call for IG receps. Building is all wood construction,

by Tesla
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iwire: I run jobs for 'catfish' feeding at the bottom end of the commercial market. The IG, and associated contract specs, stops my bosses from screwing the owner on the ground path. ( And yes they would.--- I had to withstand a screamfest from two separate owner/ bosses on wasting green wire.) The requirement for dedicated ground clear to the panel provides the owner the pretext for testing it by lifting it off the isolated grounding bar.(And, yes...they do it. They've learned by experience.) Without this spec the owner would receive a system sending the ground path regular way: through the EMT -- linked to every hunk of metal on the way....

Unless they are lifting this IG daily and tracking down points where it has been connected to the EGC in some way it is not an IG for very long.

by Tesla
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I have built raceways under major high voltage lines ( inducing 270V on the skin of parked cars and a hefty induction to the T-bar over the sales floor. -- Lighting crews had to pre-ground the grid every time they worked on it from a lift.)
in the path of intense microwave radiation ( with all of the side lobes/ refections triggering voltage induction beyond 40V in the EMT. This had the fire alarm tech choking.

How exactly did you measure 270 V on the skin of a car or 40V in the EMT?

Between what two points and what kind of meter?

by Tesla
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"SDS in nature" does not compute. Spell it
out.

You run large commercial work and SDS does not ring a bell?

"Separately Derived System"


Bob



[This message has been edited by iwire (edited 07-25-2004).]

Bob Badger
Construction & Maintenance Electrician
Massachusetts