I'm going to post this as a question rather than a statement as I've not got the regs with me, but aren't we now supposed to be ensuring either a proper TT earthing arrangement, or that the DNO fits a PME in situations where the original earthing arrangement was via the water main?
I believe it used to be classed as ok if the incoming water main was a private supply for x meters outside the property, but I'm pretty sure that this got removed at the last regs updating. I'm partly aware of this because our house is a TT system using the incoming water main as the earth, which was allowed in the regs when I checked a few years back as it was a private supply, but wasn't when I checked again a few months back, so we're now awaiting the DNO to fit a PME.
The reason for the change being the water companies are rapidly going round whole areas replacing the metal pipe with plastic, and the same with the gas, so as soon as they do that the house loses its earth connection. We've come across 2 houses in the last year where this had actually happened in the previous few months, and the Ze readings were well over the limit when we took them even with the bonding connected to water and gas. I'd expect that 90% of that whole estate had actually lost it's earth protection, which we did mention to the DNO, but apparently it's only their problem if they're supplying the earthing arrangements, and it's nobodies problem other than the householders if the original builders didn't pay for a PME connection.
I also thought the bonding to the water and gas pipes was supposed to be disconnected now when taking the Ze readings, presumably to pick up on situations where the water and gas pipes are supplying the earthing.
Happy to be corrected, but I'm pretty sure we double checked the regs on this quite thoroughly.
(fwiw, we're happy enough to leave it as is if the Ze is ok with the water connected, as long as the customer rings the DNO in our presence to arrange for a PME to be installed, but we've had to bang earth spikes in temporarily while waiting for the DNO to come out to fit a PME on the couple of occasions where the pipes had already been done).
I believe it used to be classed as ok if the incoming water main was a private supply for x meters outside the property, but I'm pretty sure that this got removed at the last regs updating. I'm partly aware of this because our house is a TT system using the incoming water main as the earth, which was allowed in the regs when I checked a few years back as it was a private supply, but wasn't when I checked again a few months back, so we're now awaiting the DNO to fit a PME.
The reason for the change being the water companies are rapidly going round whole areas replacing the metal pipe with plastic, and the same with the gas, so as soon as they do that the house loses its earth connection. We've come across 2 houses in the last year where this had actually happened in the previous few months, and the Ze readings were well over the limit when we took them even with the bonding connected to water and gas. I'd expect that 90% of that whole estate had actually lost it's earth protection, which we did mention to the DNO, but apparently it's only their problem if they're supplying the earthing arrangements, and it's nobodies problem other than the householders if the original builders didn't pay for a PME connection.
I also thought the bonding to the water and gas pipes was supposed to be disconnected now when taking the Ze readings, presumably to pick up on situations where the water and gas pipes are supplying the earthing.
Happy to be corrected, but I'm pretty sure we double checked the regs on this quite thoroughly.
(fwiw, we're happy enough to leave it as is if the Ze is ok with the water connected, as long as the customer rings the DNO in our presence to arrange for a PME to be installed, but we've had to bang earth spikes in temporarily while waiting for the DNO to come out to fit a PME on the couple of occasions where the pipes had already been done).