Service bond

Status
Not open for further replies.
P

poolboy

Member
When a house is re-piped with copper piping including a new main, pvc or sleeved copper, and there is not a ufer or electrode, a rod is now required. To reestablish a continuous bond of all metal piping, gas and water and only gas is close by, can you pick up water bond at the water heater and be considered continuous. You are able to pick up gas at the water heater so can you go the other way??
poolboy
 
Re: Service bond

First It sounds like you are talking about a grounding electrode. Here is the simple rule:
If there is 10 feet or more of metal water pipe that is in direct contact with earth (soil) it must be used as a grounding electrode. The connection MUST be made within 5 feet of where this water pipe enters the building. GAS pipes cannot be used as a grounding electrode! A metal underground water pipe shall be supplemented by an additional electrode of a type specified in 250.52(A)(2) through (A)(7). As for Bonding, To be compliant of 250.104 you must bond around a water meter where if it is removed it will disconnect the continuty of the piping system back to the panel. Gas piping and other piping in the building will be bonded by the EGC of the circuit feeding the appliance that is also connected to the piping or duct work. so in most cases you are covered there.

[ May 31, 2004, 04:48 PM: Message edited by: hurk27 ]
 
Re: Service bond

In case you are refering to bonding the interior water pipe as required by Section 250.104, where the water pipe is NOT a grounding electrode, no, you still may not bond to the gas pipe. 250.104(A)(1) lists the items that may be used to provide this bond: the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor (where large enough), or to an existing grounding electrode. Said grounding electrode will have grounding electrode conductors bonding it to the service enclosure and to the grounded conductor at the service. It is very clear the NEC wants interior water piping to be bonded to the grounding electrode system directly. The size is to be based on Table 250.66 (same size as for the GEC)

Section 240.104(B) covers "other metal piping" which includes gas piping. This section specifically permits the EGC to be the bond.
The only time we require gas piping to be bonded is when the building was wired with knob and tube, older AC(no internal bond strip) or older NM without grounds.

Earl
 
Re: Service bond

I am a little unclear what the exact situation is with the house. If the water supply to the house is metallic, it needs to be bonded within 5'. It cannot be used as a grounding electrode unless it is an acceptable conducting metal (like copper or galvanized steel), is in the ground for ten feet AND is electrically continuous, but it still must be bonded.

The wording about bonding in the codes has changed enough in the past few NEC editions, and that is very relevant to what is pertinent about grounding/bonding gas lines. Your local jurisdiction and utility have a major role in how the bonding is to be accomplished. Some of the various positions have been argued over and over here without there being a simple answer. Check your local building department.

paul
 
Status
Not open for further replies.
Top