marmathsen
Senior Member
- Location
- Seattle, Washington ...ish
- Occupation
- Electrical Contractor
gas and water line bonding
In the past, elec inspectors have had me bond gas and water lines (with one continuous #6 Cu wire) to the first means of disconnect. But recently, one allowed me bond them to a subpanel instead of the main panel. It was a lot easier and he said since both panels are grounded together, that...
forums.mikeholt.com
In the thread above the OP mentions that their inspector allowed them to bond the gas from a subpanel. I have received the same suggestion from an inspector in the past. My inspector suggested and allowed me to bond not only the gas but also the hot water and waste as well.
My question is, how is this allowed? In looking at 250.104(B) the 5 allowed attachment points are:
(1) Equipment grounding conductor for the circuit that is likely to energize the piping system
(2) Service equipment enclosure
(3) Grounded conductor at the service
(4) Grounding electrode conductor, if of sufficient size
(5) One or more grounding electrodes used, if the grounding electrode conductor or bonding jumper to the grounding electrode is of sufficient size
Obviously item 1 above makes all the rest of them moot, which begs the question, why are the rest of them there? Even still I don't see how a separate bond wire can come from a sub panel since it's not in the list. Obviously if you run a bond wire from the same panel that the "circuit likely to energize the gas" comes from then I guess that's effectively OK but technically not allowed? But what if that circuit is run from the main service panel but the bond wire is run from a separate sub panel? Is it catastrophizing to think someone may remove that feeder in the future, thus disconnecting that bond wire. I guess that makes an argument for always running it back to the service.
I guess I'm asking:
1. How is it allowed to run the bond out of a subpanel?
2. Why are those 4 other items even there?
3. If you take it for granted that running from a subpanel is OK, then is that even wise, or should it always be run to the service?
Rob
