Earthing

[Waggsnald]

Hi , can i ask a question, which may seem stupid.

I know gas , water and structure require bonding to a building but i always thought each service has to be bonded seperate to the earth bar. 

Today i have come across a bond from the earth bar to the structure then to the gas pipe. I said to the man i work with ( he has been an electrician for years) that this is wrong and a seperate earth should be ran in for each service. He told me i was wrong and all services can be bonded together as in a radial. 

Is he right?  Tried to look in the regs book but doesn't really clarify anything.

 

[Andy™]

nothing to say you cant go from one to the other or that each must have its own. best you will get is a reg in one of the other standards (BS7430 iirc) recommending that if you do the conductor is unbroken, however that does suggest that you are wrong and you can use the same cable for more than 1

 

[Waggsnald]

Thanks very much

 

[ProDave]

Just don't do as I found yesterday, and do it in brown cable. Sometimes I despair at what some people do.

 

[Waggsnald]

That one i confirm is bad practice

Just been told by an Electrical manager ( he makes out he knows the lot) that main bonding has to be seperate to services. 

 

[Andy™]

That one i confirm is bad practice

Just been told by an Electrical manager ( he makes out he knows the lot) that main bonding has to be seperate to services. 

ask him which reg states that

also mention that 6.4 of BS7430:2011 states

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. Such a bonding conductor may also be used in
association with other extraneous-conductive-parts.

why would imply that you can use the same conductor for more than 1

 

[Sharpend]

In a commercial/industrial environment it is best practice to use separate conductors as sizes may be to large to daisy chain as continuous conductor. 

 

[Waggsnald]

ask him which reg states that

also mention that 6.4 of BS7430:2011 states

why would imply that you can use the same conductor for more than 1

I agree i can’t find it anywhere but yes this could be just best practice. I will ask him to confirm tomorrow

 

[Andy™]

I agree i can’t find it anywhere but yes this could be just best practice. I will ask him to confirm tomorrow

best practice maybe, but just because you dont agree with it and its not the way you would have done it, doesnt mean its wrong

 

[Murdoch]

Ah the joys of the poorly worded BS 7671 ....

 

[Risteard]

a seperate earth (sic) should be ran in for each service.

Not a requirement.

More importantly, these are NOT earths. They are bonds. Also, the title of the topic is wrong - it is absolutely NOT Earthing. It is bonding - in this case main protective bonding.