Gas and Water Bonding - part 2

Its a PILC cable sheath earth, DNO/PME rules dont apply. You can run two separate 10mmsqs.

Regards, UKPN

Good Morning Clive.

BS7671 has nothing to say about how bonding conductors are arranged, just the connectivity. There is no reason at all why cables cannot travel to several places, or be joined, although my preferred method would be a proper 10mm (or whatever size for larger installations) crimp, which then does not have to be visible. The BS951 clamps for pipes (351?) again may be connected as you say, but again my preferred method is suitable solid crimp tags as required under the screw, as this is infinitely more reliable than the cable conductors by themselves. The NAPIT man is simply wrong (and therefore should be prevented from carrying out any certification or EICR work), the feature from BS7671 is only the connectivity. Strangely this is not an unknown requirement of certain Electricians, I would like to know why they have this idea, maybe some throwback from the 15th edition?

As you now have a plastic supply pipe you may like to consider if main bonding is a good idea, or required, and whether whatever exists is useful or satisfactory.


Regards

David

There is nothing in BS7671 to say that the bonds need to be together or distinct, or unbroken,

It is a good idea not to use joints of the kind that come undone and get forgotten to be re-tightened after the plumber has done somthing, but there is certainly no compulsion in the regulations

Mike.


PS cross post with DZs fuller answer wich I agree with. I take a long time between composing and posting sometimes.

411.3.1.2  Protective Equipotential Bonding.


Main equipotential bonding is only required on EXTRANEOUS CONDUCTIVE PARTS, like underground metal service pipes...water/gas/oil, that enter a building or introduce an Earth potential. Metal pipes that have an insulating section at the point of entry to a building do NOT need to be main bonded.


Z.

If the water is now coming out of the ground in MDPE it probably doesn't need bonding anyway (other than if the metal pipework elsewhere then goes outside again or into a different installation - in which case there may be a more appropriate location for the bond).


It's nonsense to say gas and water have to have separate bonding conductors - even the BS code of practice for Earthing specifically says that one bond may serve both (but does have a recommendation that the conductor is not cut at the intermediate clamp).


  -  Andy.

IET GN 8 Earthing and Bonding.  BS7671:2008.


I do not have the later editions. 

528.3.3 requires a common main protective bonding conductor to be continuous, so that is a pipe clamp or the like is removed the conductor remains as a single length of cable.

You could interpret that in more than one way, I do not read it as meaning  the wires have to be continuous,  -  presumably a 'Tee'  tap crimp or even a suitably supported in-line solder joint to a short flyer to the water pipe or whatever as the main bond sails past to an other destination  would also meet that requirement to the letter.

After all there are far more 'mission critical'  situations where  a sleeved solder joint in that style would be accepted....

I would like to say that in terms of the physics of connections we are not on an island, but strictly that is not true..

I hadn't thought of 528.3.3 as being the source of the unbroken requirement - mainly as neither spacing nor shielding would achieve much.


I think the guidance for an unbroken conductor when looping multiple clamps comes more directly from BS 7430 (The code of practice for Earthing):

Where both main gas pipes and main water pipes enter a location, a common bonding conductor may be used, but in such cases that conductor should be continuous or should be permanently jointed (by soldering or crimping) in order to preserve continuity.

- Andy.