Demolition Contractor Wiring

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A-1Sparky

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Hey all. I've been visiting this site for a while now and have learned alot from reading the various posts and responses. So I decided to join. I'm an electrician at a college and have an electrical contracting business as well. I recently came across some scary electrical work that was done by a demolition contractor on the campus I work at. Here is what I found: (2) sets of #2URD Triplex run in parallel in 2" SCH 40 PVC from a 3-pole 200Amp breaker in a distrubution panel to a new outbuilding with (2) 100 Amp single phase panels with main breakers. The 2" PVC was run inside an open-plenum ceiling and was about a 120' pipe run. It was not supported by a single strut strap or mineralac strap or anything. The block walls that it runs through and existing conduits are the only things holding it up. They also neglected to run an EGC to the 100 Amp sub panels. And to top it all off, the installer put (2) wires under two of the lugs of the 200 Amp breaker. This breaker's lugs are not rated for termination of more than (1) conductor. I want to point out the various violations to the architect and project engineer when they come for a final inspection. This contractor should be made to remedy the problems before he collects his big paycheck. What violations do you guys see? :wink:
 
Welcome to the zoo. :smile:

The various violations, you're already aware of. If the two feeders hit separate lugs at their load, end, they're technically not paralleled. Doubled up on the lugs is wrong.

My personal biggest concern would be the lack of an EGC. Is there none, or is the neutral being used, and if so, is it bonded at the load ends? What about electroces?
 
Hey, Larry. Thanks for the welcome and the reply. There is no EGC, but they did drive ground rods at the outbuilding's service. And they didn't bond the neutral to the GEC .
 
A1,
The ground rods will not carry enough current to trip under fault conditions.
We have had several threads on that.
The calculations center on 120V through 25Ohms in the ground rod system, and
that passes only 5Amps.
Hot to Ground Fault REQUIRES an EGC because of the physics.
I've been told that the 08 NEC requires it, finally.

Give a bid on installing the EGC, you might get the job,
and earn a bigger reputation at the college.
I worked at a university for 20 years, found a lot of skelatons,
always suggested reasons and ways to fix things.
 
LarryFine said:
The various violations, you're already aware of. If the two feeders hit separate lugs at their load, end, they're technically not paralleled. Doubled up on the lugs is wrong.

QUOTE]

Like you said these circuits are not paralled but are rather two seperate circuits. If the breaker were rated for connecting two wires under 1 lug, then can you use a single breaker to protect two different circuits as long as the circuit cables are individually rated to be on that size breaker?
Click to expand...
 
Unfortunately the college has a "conflict of interest" clause that precludes me from bidding on any on-campus work. It's too bad because I'd probably get all the work I could handle! As far as feeding (2) circuits with (1) breaker, even if the lugs are rated for (2) conductors, I don't believe you can do so. I think those breakers are for parallel feed purposes only.
 
A-1Sparky said:
Hey, Larry. Thanks for the welcome and the reply. There is no EGC, but they did drive ground rods at the outbuilding's service. And they didn't bond the neutral to the GEC .
Click to expand...

Welcome to the Forum, A-1Sparky.
I would start preparing my list of violations for the architect by explaining to him/her that it is an imminently dangerous condition that exists by virtue of the fact there there is no means to clear a line-to-ground fault.

If a fault were to occur from an ungrounded conductor to an equipment grounding conductor, the fault would be directed to the grounding electrodes (in this case ground rods) and there would be a high-resistance path through only the earth back to the main service equipment. This is very dangerous.

If the feeder service had been re-grounded at this additional building as permitted under the '05, 250.32, then the fault would have been transferred through the bonding strap to the grounded conductor and back to the transformer thereby operating the OCPD.

This information alone and by itself should be enough to show gross incompetence on the part of the demo contractor and reopen the project for someone who is qualified.:)
 
Yeah, I spoke with the engineer today, and he's gonna make the contractor sub out the work to rectify the problems. Thanks for the welcome, wbalsam1. I see you're in Jay, NY. I'm not too far away. I live in Plattsburgh.
 
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