1996 report on grounding
- Thread starter bodie
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- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Are you talking about the water pipe not to be used as a grounded conductor not or used as a grounding electrode?
I haven't read the report but, assuming the area is using the NEC there would be no choice, if the water system met the requirement of being a GE it would have to be used.
Roger
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Was any reason given for not using the water pipe as an electrode. I know we cannot use a gas pipe as an electrode. Also was the report talking about a water line for sprinklers---we cannot use that as an electrode.
the report does not state. do not use water line as a ground, but is a report used to bring to panel 5 of the code committe for not using the water line. It does not state what became of the report and panel 5. the report states the practice of using water pipe as a grounding electrode was predicated on the assumptions that grounding of a/c currant had little or no effect compared to d.c current on corrosion and that current only flows during off-normal conditions and there were no safety issues for water utility workers. some modern electronics (variable speed motors,t.v. and computers) provide dc on water lines, increasing corrosion rates. also when electrical transformers serve multiple buildings water service and distribution piping can act as parallel neutral return paths, which result in random shock. (we had this happen with 45 yr old bad neutral clamp for overhead service)
Well, if was part of a proposal it must have been rejected because the requirement to use the water piping is still in place in the 2011 NEC.
The solution to electronic equipment being a problem with grounding systems should be in the laps of the electronic manufacturers, some of these issues have been resolved in recent years.
Loosing a neutral and parallel neutral paths in urban areas with metalic water systems has been an argument for a long time as well, but at this time that has not changed the requirement either.
Roger
- Location
- Illinois
- Occupation
- retired electrician
A open grounded conductor is a serious issue for the people who work on metal underground water pipes. The American Water Works Association reports that one such worked is shocked each work day on average. The normal parallel currents are not really a safety hazard as there is no real voltage to drive a shock when you open the water pipe that is in parallel with the grounded conductor.
It is probably is a good time to revisit the issue of using the metal underground water piping system as the grounding electrode. At this point in time the rule requiring the use of the water pipe is at odds with 90.1. The required use of the water pipe requires the electrician to create a hazard arising from the use of electricity.
This could also be addressed in the plumbing codes. The plumbing code could be changed to require a dielectric fitting on the metal underground water pipe just outside of the building making the pipe no longer qualified as a grounding electrode. Or the plumbing code could also prohibit the use of metal underground water piping.
It is probably is a good time to revisit the issue of using the metal underground water piping system as the grounding electrode. At this point in time the rule requiring the use of the water pipe is at odds with 90.1. The required use of the water pipe requires the electrician to create a hazard arising from the use of electricity.
This could also be addressed in the plumbing codes. The plumbing code could be changed to require a dielectric fitting on the metal underground water pipe just outside of the building making the pipe no longer qualified as a grounding electrode. Or the plumbing code could also prohibit the use of metal underground water piping.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
I have an original copy of that report, I scanned and send a copy to Mike Holt, he may have on his website.
I did search at the AWWA website for all articles on grounding and electrical and purchased them. One of the AWWA members was a non voting member of panel 5 in the 70's and was responsible for the grounding electrode system concept.
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