grounded as grounding conductor

[arcandspark]

I'm a journeyman in OKC and have recently gone to work for a contractor who derives a great deal of his business from the city and state. Most of what we do consists of highway lighting and traffic controls.

I have hit an empass with my employer. The state requires us to pull a hot (black) and neutral (white) to feed underpass lighting. Same is fed through underground pvc conduit which goes to rigid above ground and quite often seal tight is used to turn 90's.

The problem is that the city and state have exempted themselves from NEC jurisdiction. Accordingly, my employer disregards my complaints concerning safety.

The problems are as follows:

1) due to bid requirements, no equip ground is pulled with conductors.
2) the pipe is isolated from ground due to pvc underground.
3) the grounded conductor is bonded to each fixture and used as both the grounding and grounded conductor.
4) the light fixture is grounded on one leg and fed with 480 on the other. Though there is nothing, of which I am aware, preventing this...
the wire colors used give no forwarning of the voltage to be encountered.

I have found many references in code which under normal circumstances would outlaw most of the above. However, due to the fact that the state exempts itself from nec jurisdiction, there appears to be nothing I can do about it.

In short, I am afraid that someone could easily be hurt if not killed by such poorly engineered electrical work.

I am looking for ammo to take with me on my next visit to my employers office. I would like to see this all be changed to better safeguard the lives of the individuals who will work on it...who happen to be non-licensed and inexperienced at electrical work (also due to the exemption stated above).

I was hired to do industrial work on plants,airports and the like and have only come to find this all out during a lull in the work I normally do. It truly scares me.

What are your thoughts?

 

[russ]

Re: grounded as grounding conductor

I don't like it. A fault would clear if the hot were to come in contact with the pole, because of the bond to the grounded conductor. The problem I see is what happens if you lose the grounded conductor? In that event it will try to use anyone touching the pole and in contact with the earth as a conductor.

[ January 11, 2004, 10:28 AM: Message edited by: russ ]

 

[mclain]

Re: grounded as grounding conductor

What you are describing seems to be the normal for many cities. Here is a link to an article my Mike Holt that ran in the May 2001 issue of ECM magazine. http://images.ecmweb.com/files/31/0501btb.pdf The article is call Ground Rods and Touch Voltage. It talks about streetlights and traffic signals without EGC and people getting killed by them each year.

 

[don_resqcapt19]

Re: grounded as grounding conductor

arcandspark,
If there was only one grounded to grounding bond at each underpass and if there was a disconnect at the underpass, then 250.32(B)(2) would permit the installation. With multiple fixtures on the underpass connected by metallic pipe, then you would have a violation as you would have multiple connections of the grounded conductor to grounding conductors at a single structure. If these lights would be on individual poles and if the pole has a disconnect, the installation would be code compliant. You may even be able to omit the pole disconnect using Exception #3 to 225.32.
The installation that you have described, even where it is a code violation, is safer than the ones described by Mike because there is a fault clearing path in your installation. There is no fault clearing path other than the earth in the installations that Mike talked about.
Don

[ January 11, 2004, 11:52 AM: Message edited by: don_resqcapt19 ]

 

[tom baker]

Re: grounded as grounding conductor

As the author of the Code Corner column for the International Municpal Signal Association (IMSA) Journal, I am always interested to hear of NEC issues and can bring them to the traffic signal industries attention via the journal. I know there are many unsafe street and lighting installations, as the municpalities try to claim they don't have to follow the NEC.
What I suggest is you let your employer see how it should be done, by way of an very good series of videos from the Texas Dept of Transprotation, find them at:
http://www.dot.state.tx.us/gsd/pubs/trfpubs.htm

I recommend "the importance of proper grounding" its only $2.00!, I have all of the grounding videoes and they are very well done.

If you let them see the videos, they will see equipment they are familiar with, be speaking the same language and should be able to see they have a serious problem.

Often, municapalities will try to say they don't have to follow the NEC as they are exempt, but that means they would follow the NESC. Its true that some lighting is done by cities under the NESC as they are a utility as recognized by state laws, for more information on this, here is my article on the NEC or the NESC:
http://www.dot.state.tx.us/gsd/pubs/trfpubs.htm

This latest article may be of some use, it deals with disconnecting means and grounding electrodes:
http://www.imsasafety.org/journal/janfeb/article1.htm

[ January 11, 2004, 12:49 PM: Message edited by: tom baker ]

 

[tom baker]

Re: grounded as grounding conductor

One more question. I would guess there is a ground rod at each lighting pole. Correct?

 

[arcandspark]

Re: grounded as grounding conductor

Thanks for all the input guys.

I guess what it all boils down to is that the NEC
has exempted itself from having to deal with the issues we are discussing here. Without them stepping forward and requiring adherence to code, nothing will ever be done and non-licensed people will continue to do substandard work to public buildings and structures and in the process subjecting us all to possible injury.

From my perspective, having learned the standards and codes enveloping my career, I can see a licensed electrician walking into this and being injured simply because of what he "knows" is supposed to be done...and hasn't been.

If a ground rod is supposed to be attached and is not...If a riveted #16 stinger isnt attached to the neutral conductor...or if, god forbid, the source is not grounded, then you or I will be walking into a disasterous situation.

Once you take away the standards and codes set up by our association (NEC/NFPA) and then you allow people who have no clue as to proper installation to do the work...buddy were in trouble.

Thanks again. Jim

 

[charlie]

Re: grounded as grounding conductor

If the installation is done by a recognized utility, grounding to the MGN is acceptable. In the same manner as most of our linemen, electrical people who wire capacitor banks, SCADA controls, control houses in substations, etc. are not qualified to do work under the NEC, you are not qualified to do work under the NESC. The rules under the NESC are very different with the emphasis on the end result, not what you are and are not permitted to do.

The real question is who has control of the installation. Since this type of work is done in the public rights-of-way, either the NEC or NESC may be used depending on which one is designated. If the city has indicated that the work is to be done in accordance with the NESC, follow the NESC. If you do not know the rules, ask. Some states do not use either like California since they have written their own rules.

Whether you like it or not, the body that makes the laws has the right to require anything they want. BTW, grounding to the MGN is not all bad.

 

[tom baker]

Re: grounded as grounding conductor

In Washington State our DOT is exempt from state electrical requirements, but not from the NEC. Our state law allows a local jurisdiction to do its own electrical inpections as long as the standards used are "equal or higher" than the NEC. Our DOt has its own inpectors and standards dept, and does an excellent job on its own ROW. Hihgway lighting and traffic signals are typically done to a more strict standard then the NEC. For example only OZ Gedney HLBG grounding bushings can be used.