Gas Water bonding

[AndyPRK]

The water and gas come in at the house at the same location.
This is a long way from the CU.

Can I run one wire from the CU to the pipes or do I need two ?

What size cable is best to use ?

Thanks

 

[securespark]

Can use one, as long as it remains unbroken where it attachs to the first pipe.

How long is run? What supply type have you got? Who is your DNO?

They may ask for 16mm². Or if the run is huge, it may need 16mm² anyway, but usually, 10mm² is used. In any case the total cable impedance is limited to 0.05 Ohms.

 

[AndyPRK]

It's about 50ft between CU and pipes which I can do in one length.

It's a TT supply.


Also my CU is along way from where the electric supply comes in (say 30ft). Is it still ok to bond the pipes to the cu, or should it be to the supply entry?

 

[Adam_151]

How is the CU connected to the origin?

 

[AndyPRK]

twin cable in grey sheath and seperate earth

isolator by meter

 

[ColJack]

Can use one, as long as it remains unbroken where it attachs to the first pipe.

I know that this has been asked before, but where exactly in the regs does it say that?

the lecturer at college said the same thing, but also went on to say that connection via crimped rings was also acceptible..

 

[securespark]

Col: I don't believe anything other than an unbroken conductor is acceptable.

If the conductor is cut and the joint comes loose, you lose bonding to both services, whereas if it is unbroken & it comes loose, you lose both.

Same with crimp rings: if they come loose, you get high impedance or no continuity at all.

It may not be in the regs, but using that method is (to my mind) best practice.

OP: If your supply is TT, you can drop to 6mm², as long as the 0.05 Ohms reading is not exceeded on that 15m run (unlikely).

 

[AndyPRK]

Thank you

 

[nozspark]

For 10mm you can go to about 33m

 

[RF Lighting]

It's about 50ft

~15m

 

[ColJack]

by ring crimp I meant 2 10mm²'s into a 16 or 25/6 ring crimp..

 

[securespark]

Does that provide a mechanically sound joint?

 

[RF Lighting]

Are they designed for that?

I suppose it would be alright if you filled the bit you normally crimp with solder, like in the olden days.

 

[ColJack]

if you use a decent crimper then yes, it's mechanically sound.. more so than wrapping a conductor under a screw..

you put 1mm in red crimps designed for 1.5mm, 4mm in yellows for up to 6mm so 20mm into a 25mm crimp should be fine..

 

[SparkyNinja]

528.3.3













The NIC's part 1 earthing & bonding 3rd edition has come up with that.