I'm having central heating installed, 75% done.
Plumber tells me I need an earth wire from the consumer unit to the outside gas meter.
This is quite difficult to achieve without leaving lots of earth cable visible. Are there alternative options for me? Also, as the incoming gas supply is plastic I can't see the point.
mark
Is your plumber an electrician? Why is he even getting involved in this?
He isn't. He's not getting involved as he's put it on to me. I was going to route the cable then have an electrician do the connections but that's not my question.
mark
This cross bonding is concerned with the house pipework - not the supply. And the house gas pipework is likely copper? I'm pretty certain if the gas pipe is buried in concrete etc which makes it difficult to get to the meter end, bonding to where it first surfaces inside the house will be ok. However if it simply runs under floorboards where it's too much trouble to lift them this approach doesn't comply.
Thanks for replying. The pipework is all copper. To get from the consumer unit to where the copper gas pipe enters the house is quite long route and lots of t&g floorboards to lift. Does it need to be as near the meter or house entry as possible? I guess what I'm trying to say is, can't it be connected to a copper pipe a bit more convenient.
mark
Sorry, you misunderstood me.
What I mean is - why has the issue even arisen? How does the plumber - who is not an electrician - know there is something wrong with your earth bonding?
Really all he needs to concern himself with is bonding all his pipework together at the boiler end.
Has he explained why he thinks this extra work is necessary? You might not even have an electricity supply which requires supplementary bonding. How long has the current electrical installation been in place?
Steve
If there's no bonding there, then there *is* a potential issue - simple as that.
Agreed but it is not forced to be the case - PME is not mandatory - it depends on the type of incoming supply.
If there is no existing PME arrangement, then it is probable that it is not needed.
Steve
Rewiring is recent. Central heating is in progress. Seems like the electrician forgot to put an earth into the consumer unit. I just want it to end up safe and conforming.
mark
Any CORGI plumber worth his salt would check for main equipotential bonding on the gas and advise the customer that it needs doing if it is not done.
Adam
He is. He has. Hence my original question.
mark
I dont see how you expect folk to suggest how or where to route the wire when we dont know the construction or layout of the place. All that can be said is a few generalities, such as its often not necessary to lift floorboards to route wires, and that wire can be routed externally without it being too visible - but with no further info, who knows what details are involved.
NT
This is nothing to do with PME. If the house has metallic gas pipeing then this must be included in the main equipotential bonding. This is irrespective of the type of earthing arrangement of the supply.
The requirement is that the house pipework is bonded on the consumers side of the meter as soon as is practical after it enters the house. Often this is actually implemented by effecting the bond in the external meter box if you have one, however this is not actually the letter of the requirement since it is not after entry as such.
In reality if all the pipe joints were soldered then that would achieve the desired result in practical terms. However it may not pass inspection since it is not to the letter of the regulation. There is nothing to stop you routing the main bond by a indirect route if it helps (i.e. outside and back in later, up into a first floor void etc).
If the copper pipework runs outside the house from the gas meter and then enters the house near the CU and has no branches from it before the point of entry to the house then bond the copper pipework at the point of entry to the building.
Adam
OT but coincdentally, today I had a letter from the gas co. telling me that they want to come and change my gas meter for a newer one in a couple of weeks. Having read this thread I went and checked if the existing meter has an earth bond anywhere - and yipeee (sarcastic) it hasn't. Being pessimistic, does this mean the gas fitter could come along and refuse to install the new meter (after disconnecting the old one of course) because of this lack of an earth bond? The distance from gas meter to CU and earthbond is about 3 feet!
Meter is in a semi-concealed box at side of house. A 28mm copper pipe runs up the wall and across the bedroom floor then into a landing cupboard where the boiler is housed.
I can join the earth cable to this copper pipe in the bedroom without too much trouble. This will be my 'as soon as practical' solution. It was the thought of having to route it across the bedroom and down the wall which prompted my original question.
I'm doing this to conform to regs. I don't really understand why.
Thanks for all the responses.
mark
It really needs to go where the pipe comes into the house. Unless you can prove it is a continuous length from there to where you propose fitting it.
Well, consider the fact that the pipe from the street is plastic. A metal one running through earth would provide an earth of sorts - but plastic won't. The copper within the house is connected to what? A boiler, gas fire, cooker etc all of may also be connected to electricity. If one of those developed a fault it's conceivable the electricity could get to the pipe. And make all the copper pipe 'live'. I know it's unlikely but protective measures have to allow for every possibility.
"Mark" wrote
My understanding was that the point of connection to piping should be accessible so that the presence and security of a pipe clamp and cable could be checked in future. If this point would be under flooring at the point of entry into the house, shouldn't the connection deliberately be made in a cupboard or other downstream more accessible location anyway??
Phil
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