A licensed electrical contractor I work with says running a ground wire from a recpt to a water pipe bonding with a copper strap is an approved method for obtaining a ground from a 2 wire system. Example: knob and tube wiring, he ran a #12 wire from the recpt to a water pipe (3/4 galv) to acheive a ground. I argued with him since it was my belief this was not an approved method.
Please shed some light please. I have a 2002 NEC. Please reference some code so I can better understand, also a suggested approved method if his is not.
Jon, I believe you are correct, you must run the ground to within 5 feet of water line point of entry, or you could run it into the panels ground bar. This or may not be accepted where you are. Here in Mass we are not allowed to do this. They have deleted 250.130(C)
Re: Grounding to water pipe#80016 02/14/0206:45 PM02/14/0206:45 PM
Beach - you are in Calif. - the NEC 1996 is the state adopted code (not '99 or 2002) -...so
250-50(b)Excetion - says "shall be permitted to be grounded to any accessible point on the GES as described in 250-81, or to any accessible point on the GEC."...going to 250-81.... 250-81(a) - Metal underground water pipe - there is no requirement for attaching within 5' of entry into the bldg....(unless I missed somthing but I don't think I did) ....so - your elect. contractor wired this correctly....until Calif. finally gets around to adopting the 1999.
Re: Grounding to water pipe#80017 02/14/0207:44 PM02/14/0207:44 PM
The 5 foot rule for the water pipe connection first appeared in the 1993 NEC. If the grounding connection was not made within the first five feet from the point where the water service enters the building, it would not appear to be done correctly.
Re: Grounding to water pipe#80020 02/15/0209:09 AM02/15/0209:09 AM