equipotential bonding??
- Thread starter r896neo
- Start date
It is water pipes and other items in a bthroom that need bonding.
Where is the boiler located?
Where is the boiler located?
hi, im not sure. After fitting and payment i got the invoice from the plumber who attached a generic letter about equipotential bonding and that he recommended i get it done.
There is only one bathroom in the house and after having a look, the only earth cables i have seen both in kitchen and bathroom connect the hot water and cold supply together, at each sink.
Aside from that i have not soon any other earthing.
Boiler was sited in place of the old hot water tank which was removed and there is no connection between any of the gas or water feed/ output pipes at the base of the boiler.
any more info just ask. thanks for your help.
There is only one bathroom in the house and after having a look, the only earth cables i have seen both in kitchen and bathroom connect the hot water and cold supply together, at each sink.
Aside from that i have not soon any other earthing.
Boiler was sited in place of the old hot water tank which was removed and there is no connection between any of the gas or water feed/ output pipes at the base of the boiler.
any more info just ask. thanks for your help.
There's a useful diagram showing equipotential bonding here : http://www.worcester-bosch.co.uk/index.php?fuseaction=site.viewFile&id=190261
Basically, all the copper pipework that exits a boiler must be bonded together using 10mm2 earth cable and suitable BS-approved clamps as shown in the diagram and the gas pipe must be earthed within 60cm of the meter - this then terminates at a main earth terminal near or inside the main consumer unit.
I was told this wasn't notifiable, so did the above in 10mm2 earth cable and also upgraded the main earth cable (from the newly fitted earthing block to the main earth terminal on the incoming supply) to 16mm2.
There's some more info here : http://www.ultimatehandyman.co.uk/earthing_supplementary.htm
If you're going to DIY, then you must of course take all the necessary precautions when working around your CU. Only do this if you're competent and capable !
Basically, all the copper pipework that exits a boiler must be bonded together using 10mm2 earth cable and suitable BS-approved clamps as shown in the diagram and the gas pipe must be earthed within 60cm of the meter - this then terminates at a main earth terminal near or inside the main consumer unit.
I was told this wasn't notifiable, so did the above in 10mm2 earth cable and also upgraded the main earth cable (from the newly fitted earthing block to the main earth terminal on the incoming supply) to 16mm2.
There's some more info here : http://www.ultimatehandyman.co.uk/earthing_supplementary.htm
If you're going to DIY, then you must of course take all the necessary precautions when working around your CU. Only do this if you're competent and capable !
Here's where the confusion comes in.
There is NO electrical regulation in BS7671 that says that the pipes from a boiler must be supplementary bonded. Plumbers may like to do this ("I've always done it like that mate")
and they also like to bond pipes in a kitchen (also now not required).
Supplementary bonding is required in bath or shower rooms but nowhere else in most houses.
Bonding the pipes from a boiler is a nice thing to do but not mandatory.
Useful if the boiler is (say) in a cupboard next to the bathroom as it will bond the pipes going into the bathroom. You still need to extend this bonding to other items in the bathroom (lights, shaver point, metal drain pipes, etc) and confirm the bonding is correct using the relavent test equipment.
Main bonding to gas & water services IS mandatory and usually done in 10mm cable.
Supplementary bonding is usually dome in 4mm.
All of this will change next year when the new regs come out (17th edition).
There is NO electrical regulation in BS7671 that says that the pipes from a boiler must be supplementary bonded. Plumbers may like to do this ("I've always done it like that mate")
and they also like to bond pipes in a kitchen (also now not required).
Supplementary bonding is required in bath or shower rooms but nowhere else in most houses.
Bonding the pipes from a boiler is a nice thing to do but not mandatory.
Useful if the boiler is (say) in a cupboard next to the bathroom as it will bond the pipes going into the bathroom. You still need to extend this bonding to other items in the bathroom (lights, shaver point, metal drain pipes, etc) and confirm the bonding is correct using the relavent test equipment.
Main bonding to gas & water services IS mandatory and usually done in 10mm cable.
Supplementary bonding is usually dome in 4mm.
All of this will change next year when the new regs come out (17th edition).
The WB links states that 'The IEE Wiring Regulations (BS 7671:2001) require that extraneous conductive parts including...metal central heating systems...be connected to the main earthing terminal of the electrical installation.'
I guess most plumbers take that to include the flow/return and other copper pipework that emerges from a boiler and the easiest way of bonding those pipes is as shown in the PDF.
Is the WB PDF not correct ?
I guess most plumbers take that to include the flow/return and other copper pipework that emerges from a boiler and the easiest way of bonding those pipes is as shown in the PDF.
Is the WB PDF not correct ?
The pipework on the majority of boilers is not extraneous, therefor does not require bonding (and even if it was extraneous it would require MAIN bonding, not supplementary bonding)
Sounds like the plumber has left a note saying there is no MAIN EQUIPOTENTIAL BONDING - And I assume he truley means to the gas supply and water supply into the house.
Forget the supplementary bonding for a moment, and check the main eq bonding.
Forget the supplementary bonding for a moment, and check the main eq bonding.
your right lectrician, as the gas mains supply, meter and meter-boiler pipework has all just been installed there appears to be no bonding of these. not sure about the mains water but will investigate and post pics later. cheers
Did some investigating today and here are links to a couple of pics.
here is the gas meter, (in brown box) definately no earth cable of any kind on the meter to boiler supply pipe shown in pic.
http://i60.photobucket.com/albums/h33/r896neo/DSC00531.jpg
http://i60.photobucket.com/albums/h33/r896neo/DSC00532.jpg
Here are pics of earthing terminal.
http://i60.photobucket.com/albums/h33/r896neo/DSC00529-1.jpg
http://i60.photobucket.com/albums/h33/r896neo/DSC00530.jpg
The cable in top left terminal goes to cu, top right goes up conduit with upstairs ring main, bottom left terminal goes into floor cavity with d/stairs ring main, but i lifted a board just in front of cu cabinet and the bottom left cable does not connect to the mains water as far as i can tell.
Mains water pipe is accessible just about, and i assume it is the 30mm(ish) lead one?
here is the gas meter, (in brown box) definately no earth cable of any kind on the meter to boiler supply pipe shown in pic.
http://i60.photobucket.com/albums/h33/r896neo/DSC00531.jpg
http://i60.photobucket.com/albums/h33/r896neo/DSC00532.jpg
Here are pics of earthing terminal.
http://i60.photobucket.com/albums/h33/r896neo/DSC00529-1.jpg
http://i60.photobucket.com/albums/h33/r896neo/DSC00530.jpg
The cable in top left terminal goes to cu, top right goes up conduit with upstairs ring main, bottom left terminal goes into floor cavity with d/stairs ring main, but i lifted a board just in front of cu cabinet and the bottom left cable does not connect to the mains water as far as i can tell.
Mains water pipe is accessible just about, and i assume it is the 30mm(ish) lead one?
Bond the water just after the mains stop tap, and the gas just as it enters through the wall, or in the gas meter box outside.
10mm earth to each from the main earth block in the pic.
10mm earth to each from the main earth block in the pic.
in terms of the cable run could i bond to the gas pipe inside the meter box through the wall and then into the floor cavity. Then on to earthing block? it would be less disruptive due to exposed floor boards d/stairs and gas pipe entering house upstairs.
Also CU earthing block etc is by the front door and i can get access to water main easier there, the stopcock is further inside the house. So can i bond to the lead pipe there, by the door as it enters the house?
Also CU earthing block etc is by the front door and i can get access to water main easier there, the stopcock is further inside the house. So can i bond to the lead pipe there, by the door as it enters the house?
Bonding clamps must be accessible.
Must be within 600mm of the consumer side of the gas meter and consumer side of the main stop tap. Must be before any tees or branch pipework.
If you run from main earth terminal to water to gas you must not cut the earth at the water clamp - just remove insulation and place unter terminal by forming a U.
In the gas meter box outside is fine.
Use blue 'wet area' clamps.
Must be within 600mm of the consumer side of the gas meter and consumer side of the main stop tap. Must be before any tees or branch pipework.
If you run from main earth terminal to water to gas you must not cut the earth at the water clamp - just remove insulation and place unter terminal by forming a U.
In the gas meter box outside is fine.
Use blue 'wet area' clamps.
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