Bonding Of The Same Service

[a1guvner]

Morning guys,
Thought I would throw one out there, on an eicr this morning and the main gas service comes in to a dedicated outbuilding separate from the main commercial building, the previous installers have run the bond from the met to the point of entry in a plant room, then from this point (seperate lugged cables) runs to the outbuilding to bond the gas again,
My gut feeling is they should be two seperate cables but looking for thoughts.

 

[westward10]

Morning guys,
Thought I would throw one out there, on an eicr this morning and the main gas service comes in to a dedicated outbuilding separate from the main commercial building, the previous installers have run the bond from the met to the point of entry in a plant room, then from this point (seperate lugged cables) runs to the outbuilding to bond the gas again,
My gut feeling is they should be two seperate cables but looking for thoughts.

Is it the same service?
You can use the same conductor for main protective bonds as long as it is continuous (your example is not) or, install another earth terminal so the disconnection of one does not affect continuity the other.

 

[a1guvner]

Is it the same service?
You can use the same conductor for main protective bonds as long as it is continuous (your example is not) or, install another earth terminal so the disconnection of one does not affect continuity the other.

Yes they are both the same gas main, but I agree if the bond at the plant room failed the external intake would not be protected

 

[westward10]

Yes they are both the same gas main, but I agree if the bond at the plant room failed the external intake would not be protected

Can you physically see the gas service where it passes between the buildings and if you can does it need two bonds?

 

[a1guvner]

Can you physically see the gas service where it passes between the buildings and if you can does it need two bonds?

Unfortunately not, it does go underground.

 

[westward10]

Unfortunately not, it does go underground.

Got me thinking this and just looked in GN8 and Figure 5.13 which I think shows your set up ( they are supplied from the same DNO source?).
So I should say that bond should be continuous or connected in such a way the disconnection of one will not affect the other.

 

[Risteard]

as long as it is continuous (your example is not)

It is definitely accepted as good practice to ensure that it is continuous, but I doubt whether you can find any Regulation to backup any requirement for it.

 

[westward10]

It is definitely accepted as good practice to ensure that it is continuous, but I doubt whether you can find any Regulation to backup any requirement for it.

See GN8 Section 5.2

 

[Risteard]

See GN8 Section 5.2

I will have a look at it later, but unless it quotes a Regulation it must be remember that GN8 is GUIDANCE Note 8.

As I said, unbroken main protective bonding conductors are generally accepted as good practice.

 

[westward10]

I will have a look at it later, but unless it quotes a Regulation it must be remember that GN8 is GUIDANCE Note 8.

As I said, unbroken main protective bonding conductors are generally accepted as good practice.

Fair point, out of all the Guidance Notes I find this one of the best.

 

[westward10]

This is making me think, as there is no Reference in BS7671 why is the Guidance Note showing it, is this why we have Safety Electrical Connection - Do Not Remove notices. My posts to the OP must be incorrect.
Does anyone have a recollection of any DNO insisting main bonds for PME systems must be continuous as this seems to be in the back of my head.

 

[snowhead]

What else is in the dedicated building, any Electrical supply or is it just a Meter?

 

[a1guvner]

What else is in the dedicated building, any Electrical supply or is it just a Meter?

Yes it is just a meter building primarily, it does have the main tx in a seperate room to the gas meter but this room only has general small power and lighting but no electrical distribution and both rooms have separate external doors of which only the dno gave access to the tx.

 

[Deleted member 26818]

There is no requirement for bonding conductors to be continuous.
Where a service enters premises at multiple positions, bonding is required at each point of entry.