I posed this question in CDN forum, no response, so, may I have US elec. thoughts on the matter?
question posed on cdn forum as follows....
Increasingly, in residential work, IPEX water piping is being used. This is the flexible piping with the polyethelyne layers used in resi as an alternative to copper piping. My question is, we normally bond the gas pipe to the cold water pipe at the Hot Water Tank. However with the IPEX piping running throughout the entire house, is this still acceptable method of bonding? In the eyes of the CEC, does the Ipex provide a continuous bond from the water main?
I have been hounding the guys to be sure that they bond the gas pipe at the panel ground when a house has Ipex, however when I observe other contractors jobs, I notice they still bond the gas at the HWT.
In the US at least, metal water piping is required to be bonded using a jumper that is sized relative to the service, even when the underground portion of the pipe is _not_ suitable as a grounding electrode.
_Other_ piping systems are required to be bonded based upon the size of the circuit which might energize the piping. The furnace circuit, for example, or the gas range circuit, with bonding done from the egc of those circuits to the pipe.
Most of the gas hot water heaters that I am aware of don't require electricity at all; though I have seen modern heaters with forced draft systems that require electricity for the blower. If there is no circuit to the heater, and the water pipes to and from the heater are plastic, then bonding the heater to the steel gas piping probably does nothing to help ground the gas pipe...though if the pipe is grounded, then it might help ground the water heater
I don't think we're concerned here with a short in the water heater, or the toilet, etc. Rather, I think we are tryiny to protect from these systems being energised by something else- say, a frayed house wire, or apliance that falles into a sink- by providing a good ground path, so the breaker will trip. With that in mind, if your pipe is plastic, you need not bond it at all. Any metal pipe needs to be bonded. The gas line you mention raises an interesting question- what do you do if the gas line is a plastic-coated metal line? I believe that, in this situation, the bonding provided when the water heater has its' igniter wired up is enough. If, instead, there is a pilot light, I don't really see a need to bond it at all.
Originally posted by John Steinke The gas line you mention raises an interesting question- what do you do if the gas line is a plastic-coated metal line?
I presume you're referring to "CSST" (Corrugated Stainless Steel Tubing) products, such as Gastite, Omegaflex, Wardflex, etc. If so, the outer jacket can be stripped off with a razor knife, near a fitting, and a ground clamp can be applied, as long as it's not torqued down to the point where it crushes the corrugations. This will NOT effect the operation/integrity of the pipe, but will offer you a place to bond.
When I install this type of pipe, hoever, I usually enter the house with steel pipe, into a manifold, then branch out with CSST. I do know others, however, that run this stuff in from the meter. It's ugly, but permitted.