ECN Forum
Posted By: Admin Ground Wire in Conduit? - 06/07/04 12:54 AM
(submitted via Joe Tedesco)
Quote
We had an incident at work where an employee was dispatched to secure a loose wall pack. The employee went to inspect the light and was shocked when he touched the fixture and could not let go, and was rushed to the hospital. When he came back to work he was fired for not working safely.

He was shocked because the conduit was broken loose from the fixture and a line wire was partially stripped. The conduit was the only ground.

I was wondering if it is a violation of any codes to not have a ground wire running through the conduit or from the conduit to the fixture.

If you cant answer this can you point me in a direction to help me find out.
I work in Illinois.

Thanks,
Chad

[This message has been edited by Webmaster (edited 06-06-2004).]
Posted By: Trumpy Re: Ground Wire in Conduit? - 06/07/04 12:58 AM
Personally,
I would have isolated the circuit before even touching the fitting.
Or at least tested the body of it to make sure it was not live.

[This message has been edited by Trumpy (edited 06-06-2004).]
Posted By: Dave55 Re: Ground Wire in Conduit? - 06/08/04 11:54 PM
I'm with Mike on the issue of cutting the power to the lighting circuit. Does your shop have Lock-Out Tag-Out rules in place?

On the issue of grounding the fixture, I believe wall-packs have instructions with the units regarding grounding.

Dave
Posted By: DougW Re: Ground Wire in Conduit? - 06/09/04 04:06 AM
Unless it's a circuit requiring an isolated ground, using the raceway (metal) as a grounding path is accepted practice in Illinois.

I'm a big fan of non-contact "volt-ticks", for reasons like the example in the original post.

A reusable $15 investment beats a $50 co-pay for an ER visit...
Posted By: Trumpy Re: Ground Wire in Conduit? - 06/09/04 12:17 PM
Sure,
I use a Non-Contact (Modiewark) Device at voltages over 11kV.
But, I would NEVER fail to use a decent reference to Earth, with Low Voltage stuff, using a pre-tested Cord-set and a set of 750V Duspols!!.
Take care of yourself I say!. [Linked Image]
Posted By: Trumpy Re: Ground Wire in Conduit? - 06/14/04 09:13 AM
Even so guys,
I can't help that this sentence makes me think:
Quote
He was shocked because the conduit was broken loose from the fixture and a line wire was partially stripped. The conduit was the only ground.
Shouldn't there have been some sort of a smoothed edge, on the inside of the metallic conduit, to prevent the wires from being damaged, should the fixture come adrift from the conduit?.
Regardless of that, it sounds to me like niether the fixture or the conduit was grounded or the said grounding was defective, as the circuit OCP should have operated because of the shaved phase wire, with the Neutral carrying the Fault current.

Just to sort of put what I typed above into plain English:
[quote]But, I would NEVER fail to use a decent reference to Earth, with Low Voltage stuff, using a pre-tested Cord-set and a set of 750V Duspols!!.[quote]
I use this method all the time with Domestic faults work, using a known working socket-outlet (receptacle) as a Ground and Neutral point to reference tests from, where you are not sure whether the N or E wires are connected at the panel.
People have been injured or even killed here when home-owners do their own disconnections and not knowning (or bothering to find out) which fuse supplies a given circuit, just cut the Neutral and Earth wires. [Linked Image]
Posted By: nesparky Re: Ground Wire in Conduit? - 06/14/04 09:58 PM
While using the metalic condiut for the ground is an accepted practice, I personally do not like it.
The above incident is a prime example of why. Have seen and measured current up to 15 amps on conduit (20 Amp Circuit breaker). The breaker does not trip because the neutral has failed and the conduit has a high enough impeadance not to allow the breaker to see a fault. The reasons for the too high impeanance are many and include loose fittings, corrosion, and conduits that have come apart, even saw one repared with PVC. IMHO it"s better to pull a ground wire.
Testing does help. But in this case a lost time accident followed by a loss of job was a CYA on the part of the company. It does nothing to prevent another employee from making the same mistake. [Linked Image]

[This message has been edited by nesparky (edited 06-14-2004).]
Posted By: DougW Re: Ground Wire in Conduit? - 06/18/04 05:03 AM
Trumpy: it sounds like someone may have tried to shave a little time off the job during install, and shaved the insulation off the conductor instead! I'm sure we've all seen it before, and we'll see it again.

Newbies, DIYers or lazies... take your pick.
© ECN Electrical Forums