main bonding

[ample current]

Is it ok to clamp 10mm earth cable to the gas pipe then to the water pipe and then to the Installation earthing terminal or do the have to be sepatete cables, the cable runs are about 3m.

Many thanks in advance
Mark

 

[malcolmsanford]

Yes you can daisy chain a bonding conductor as you say. It is preferable to leave it as 1 continuous cable, but that is not a regulation just a guide and good practice

 

[Edd]

I always thought it was a reg that it was ok to bond using one cable but couldnt be cut!
must be one of those misconseptions where people read and here something and assume its regs and then it just gets passed along as regs.. thanks learn somthing new everyday..
Saying that I would be unhappy to have a joint just incase it becomes disconected then you loose both bonds and some of them crappy earth clamps just ask for the cables to fall out....

 

[Graeme Harrold]

I was under the impression it could be done, think the word used is "contigious", not got the regs to hand....

 

[telectrix]

that's the exact reason you should only use an uncut cable if using 1 for both gas and water.

 

[Dan23584]

I agree, one continuous cable to both.

 

[Octopus]

This is a great example where BS 7671 should be written in an unambiguous manner. As others have said its good practice and in the guidance notes you don't have too!!!

 

[Guest123]

GN8 only 'recommends' an unbroken conductor.

There isn't a hard & fast reg but it is best electrical practice IMO, just incase one service or the other is altered etc.

528.3.3 could be construed as applicable here, depending on your own interpretation of BS7671.

 

[WDMDL]

My tutor was of the opinion that one cable for both services was acceptable, so long as it wasn't joined at the BS951 or similar. He referred to 528.3.3.

Nothing wrong with through-crimping away from the BS951 though, so that the cable can be looped round the terminal in the spirit of 528.3.3

I chose to do it that way when a renovation on a particular house resulted in the water supply now entering on the opposite side of the house. saved a lot of hassle!

Simon.

 

[Geordie Spark]

I always thought it was a reg that it was ok to bond using one cable but couldnt be cut!
must be one of those misconseptions where people read and here something and assume its regs and then it just gets passed along as regs.. thanks learn somthing new everyday..
Saying that I would be unhappy to have a joint just incase it becomes disconected then you loose both bonds and some of them crappy earth clamps just ask for the cables to fall out....

Unless you crimp or solder lugs onto the cables.

 

[gdr7671]

yes you can but do not​ cut the cable at the first connection

 

[malcolmsanford]

yes you can but do not​ cut the cable at the first connection

Why not?

I think we are stretching the interpretation angle a little if quoting reg 528.3.3 in regards to a bonding conductor having to be continous. In fact if you wanted you could work it the other way and have the reg interpret a reason not to have it so.

The reg relates to electrical services, the bonding, when it is within proximity to one or more non electrical service, the gas and water pipes, and so shall be arranged that any forseeable operation carried out on the other service will not cause Damage to the electrical service or the converse.

It then gives us the options of suitable spacing between the services or use of mechanical or thermal shielding, which having a continous cable, gives neither.

In fact you could say that having the continous cable could cause damage if a plumber was working on a pipe and there was not enough slack for them to be able to work on say braizing, because the cable was continous and he/she could not keep the bonding out the way of the flame.

OK they could disconnect all terminations and take the bond away completely, but would they bother to reconnect, would they go through the chew of trying to fit a 10mm "eye" onto a BS 951 !!. Perhaps yes and perhaps no, but to my mind if the plumber was in two minds to bother to reconnect the bonds, he may feel more inclined to do so if they were lugged.

To be honest I see no problem with running a cable from the MET to a pipe, cutting it and lugging it, then lugging another section of cable and taking it daisy chain to another pipe and so on.

How many sparks have struggled, especially now with trying to "eye" a 10mm cable onto a BS 951 clamp, and to be honest have said that's good enough, when the connection wasn't mechanically as sound as it should be.

Bottom line is preferred method would be a bonding cable for each service then lugged onto a BS 951 clamp. If you have to daisy chain then yes a continous conductor is preferable, but if I saw one that had been cut and lugged as above I would not loose too much sleep over it.

 

[johnboy6083]

whilst on the subject of main bonding, whats your gents opinion on bonding to production pipework, that enters and leaves a building?
I work in pumping stations, and treatement works, and we have pipework that enters and leaves a building. Should it be bonded at entry and exit, as close as possible to the entry/exit? should it be bonded at one end, and assume that it is then at the same potential as the MET?
Can the SWA to the pumps (cable over 50mm2) be used as main bonding, as the pumps and bases are steel, and electrically continious?

Id be interested in your opinion.

John

 

[malcolmsanford]

John if they are extraneous conductive parts then yes they should be bonded, reg 4113.1.2 (iii).

Not sure why you want to bond them on exit mate, but certainly on entry.

As for the 50mm SWA well normal SWA will give you copper eqiv of about 32mm and XPLE dead on the 25mm required in reg 544.1.1

Had to edit that of course 50mm 2 core XPLE would only be about 22mm copper eqiv and therefore not suitable

 

[gdr7671]

I agree entirely with you. I have had refusals to connect supplies by DNO's for cutting and lugging bonding cables. Their argument being if disconnected by a plumber or gas engineer at the first connection for any reason, the bonding to the final (or following connections would be lost. They have argued reasons about the ESQC regulations 9 & 26 although i can find no mention of this in this document.