Many of us feel that what 544.1.2 says about main bonding when there is an 'insulating section' or meter in a service supply pipe is really 'wrong' - seemingly defeating the whole purpose of main bonding, by leaving the only truly extraneous-conductive-part that actually needs to be bonded without bonding!
Whilst it is (IMO) no excuse for what 544.1.2 says, it occurs to me that if it said what many of us would prefer, then this might invoke the need for supplementary bonding in many bathrooms - since, without MPB being attached on the customer side of an insulating section, one may not be able to guarantee that 701.415.2(vi) was going to be (and remain) satisfied.
I have an almost similar situation in my house. Although (per 544.1.2) the water supply is main bonded on my side of the meter, there is an 'insulating section' (plastic bodied flow detector) a couple of metres downstream of that - which might make it difficult to guarantee that 701.415.2(vi) was (and would remain) satisfied. I have 'dealt with' that by putting a strap across the flow detetctor, thereby ensuring that the house's pipework is 'effectively connected' to the MPB - but even that is not straightforward, since some people then say that I have thereby introduced a hazard into the house by having the effect of ('unnecessarily') earthing the house's pipework.
Kind Regards, John
Whilst it is (IMO) no excuse for what 544.1.2 says, it occurs to me that if it said what many of us would prefer, then this might invoke the need for supplementary bonding in many bathrooms - since, without MPB being attached on the customer side of an insulating section, one may not be able to guarantee that 701.415.2(vi) was going to be (and remain) satisfied.
I have an almost similar situation in my house. Although (per 544.1.2) the water supply is main bonded on my side of the meter, there is an 'insulating section' (plastic bodied flow detector) a couple of metres downstream of that - which might make it difficult to guarantee that 701.415.2(vi) was (and would remain) satisfied. I have 'dealt with' that by putting a strap across the flow detetctor, thereby ensuring that the house's pipework is 'effectively connected' to the MPB - but even that is not straightforward, since some people then say that I have thereby introduced a hazard into the house by having the effect of ('unnecessarily') earthing the house's pipework.
Kind Regards, John