Any documented cases of shocks/deaths in showers due to using pipes for EGC?250.130(C

[n0vahawaii]

Have you heard of any documented cases of shocks or deaths due to improper use of water pipes as equipment grounds?

It is a common practice in my area for electricians and handymen to "upgrade" 2-prong receptacles to 3-prong by adding external jumpers to nearby water pipes to add a "ground". I have had numerous cases of customers being shocked in the shower, while washing their hands, as well as damage to pipes from electrolysis and arcing loose clamps. I'm going to make a 2017 proposal to have art. 250.130 reworded and to remove the section "(C)" allowance for using the grounding electrode system as a means for equipment grounding. This code is often misunderstood to those who don't understand that only the first 5 ft of the piping is part of the electrode system. I know that that documented deaths have been very persuasive in other code changes and if anyone out there knows of documents case that I can use in my proposal it would really help my case. Also if anyone knows when 250.130(c) was added to the NEC that information would help my argument that 250.130 is obsolete now that GFCI technology exists. Hopefully we can get this code out by 2017 and save a lot of lives in the future.
Thank you for reading.
Keith Baum

 

[charlie b]

I honor your intentions, and I offer you a sincere welcome to the forum. But I must beg to disagree with you on this topic.

If someone receives a shock while washing their hands or taking a shower, it will not be because someone replaced a 2-prong receptacle with a grounded receptacle, and then connected the ground screw to a point on the water system more than 5 feet from the pipe?s entry into the house. An EGC never carries current. What, never? No never! What, never? Well, hardly ever! (Apologies to Gilbert & Sullivan)

A shock like you are describing can only come about if something else is wrong within the electrical system. So don?t blame the EGC connection to a water pipe. Instead blame the old and worn down refrigerator, or the 1960?s era clock radio, or the wire that got nicked by a drywall screw, or the fact that someone thought they could solve the ?no ground connection? problem by connecting a jumper wire from the neutral screw to the ground screw on some other receptacle.

I think 250.130(C) is OK as written. It is not the cause of unsafe installations. Equipment failures and incorrect wiring are the causes of unsafe installations.

 

[don_resqcapt19]

... would help my argument that 250.130 is obsolete now that GFCI technology exists. ...
Keith Baum

Per 250.114 the fact that the circuit has GFCI protection does not eliminate the need for an EGC.

I also agree with Charlie, the use of the water pipe as part of the equipment grounding sytem is not the cause of shocks. There is something else going on in the system to cause that.

 

[mwm1752]

Does sound like a parallel path with the grounded conductor, undersized grounded conductor or damaged grounded conductor.

 

[petersonra]

Does sound like a parallel path with the grounded conductor, undersized grounded conductor or damaged grounded conductor.

how would an undersized grounded conductor cause this?

 

[mgookin]

Open neutral somewhere?

 

[n0vahawaii]

Unfortunately I have seen this happen in many cases. Please remember that the wiring in these cases is old knob and tube with insulation of the rubber wrapped in cotton type which has dried out and cracked over the past 80+ years since originally being installed. A fault occurs between the aged conductor and a metal enclosure and is connected to a water pipe that is not properly bonded to service. It becomes electrified. Im not making this up. I feel that 406.4(D)(2) has rendered 250.130(C) obsolete and presents a hazard. The wiring being knob and tube means it has no metallic raceway system for grounding to the earth as specified in 250.4(A)(1) because the knob and tube neutral conductor is grounded at the service. The old metal boxes are electrically isolated from the wiring method and if a fault were to occur from an energized wire it would trip the GFCI if a shock occurred.

 

[n0vahawaii]

I believe that it is likely that there are those out there who are less fortunate than my shocked customers who paid for this wiring mistake with their lives. Please no offence but kindly hold any assumption or second guesses. Im just trying to collect data at this point.

 

[n0vahawaii]

The wiring being knob and tube means it has no metallic raceway system for grounding to the earth as specified in 250.4(A)(1) because the knob and tube neutral conductor is grounded at the service. The old metal boxes are electrically isolated from the wiring method and if a fault were to occur from an energized wire it would trip the GFCI if a shock occurred.

What I meant to say was is I feel that in the case of knob and tube 250.4(A)(1) is satisfied by the neutral being grounded and 250.4(A)(3) is satisfied by 406.4(D)(2) and although 250.4(A)(2) calls for Grounding of Electrical Equipment I feel that a metal outlet box supplied by knob and tube may be interpreted as isolated and subject to 250.86 type exception in lieu of the situation.