JFletcher
Senior Member
- Location
- Williamsburg, VA
Looked at a home yesterday that needs some fairly straightforward work, tho two things came up I'm not entirely familiar with:
#1: There is no ground wire for the cable demarc, which is at the other end of the house (70') from the service and ground rods. Am I interpreting 830.100(A)(4)* exception and 830.100 (B)(3)(1)* correctly in that I can use an insulated ground wire of at least 14ga to bond to the bonded water pipe, which is within 20' of the cable demarc?
#2: There is a 3rd ground rod (first two being at the service) outside of the full bath (~35' away) that has a #6 solid bare copper wire going to a clamp on the hot water pipe to the tub valve. This rod and wire do not go to anything else, and I was told this was installed because a previous owner was getting shocked in the shower. The water pipe is bonded with solid #4 on the feed side of the water heater (cold water line) just a few feet from the panel. Is this okay as-is as a supplementary electrode, or does it have to be bonded to the other 2 rods? Could it be eliminated by supplying a bonding jumper from hot to cold water lines?
#3 There are 4 steel 4sq boxes in the attic which are not bonded, because the original cloth NM has no ground wire. This doesnt sound kosher to me tho I can't find a code reference atm. Is this okay, and, if not, would switching to plastic or fiberglass boxes make it code-compliant?
*2008 NEC code refs
#1: There is no ground wire for the cable demarc, which is at the other end of the house (70') from the service and ground rods. Am I interpreting 830.100(A)(4)* exception and 830.100 (B)(3)(1)* correctly in that I can use an insulated ground wire of at least 14ga to bond to the bonded water pipe, which is within 20' of the cable demarc?
#2: There is a 3rd ground rod (first two being at the service) outside of the full bath (~35' away) that has a #6 solid bare copper wire going to a clamp on the hot water pipe to the tub valve. This rod and wire do not go to anything else, and I was told this was installed because a previous owner was getting shocked in the shower. The water pipe is bonded with solid #4 on the feed side of the water heater (cold water line) just a few feet from the panel. Is this okay as-is as a supplementary electrode, or does it have to be bonded to the other 2 rods? Could it be eliminated by supplying a bonding jumper from hot to cold water lines?
#3 There are 4 steel 4sq boxes in the attic which are not bonded, because the original cloth NM has no ground wire. This doesnt sound kosher to me tho I can't find a code reference atm. Is this okay, and, if not, would switching to plastic or fiberglass boxes make it code-compliant?
*2008 NEC code refs