Gas Bonding

[glenmac]

Hi I’m still doing my apprenticeship, and I was wondering if you guys can help me.
There are 2 flats, one above the other.
Both gas meters are side by side out the front of the ground floor flat.
The gas bond for the ground floor flat has taken the 10mm earth cable from the CU to the gas meter box and bonded, it then continues to the gas meter for the top floor flat and bonded (with no break in cable).
The top floor flat has a 10mm earth cable from its own CU to the gas pipe within 600mm of point of entry of the dwelling.
In short this means that both CU’s are earthed to the same gas pipe. Is this acceptable.

 

[hughesy]

Hi I’m still doing my apprenticeship, and I was wondering if you guys can help me.
There are 2 flats, one above the other.
Both gas meters are side by side out the front of the ground floor flat.
The gas bond for the ground floor flat has taken the 10mm earth cable from the CU to the gas meter box and bonded, it then continues to the gas meter for the top floor flat and bonded (with no break in cable).
The top floor flat has a 10mm earth cable from its own CU to the gas pipe within 600mm of point of entry of the dwelling.
In short this means that both CU’s are earthed to the same gas pipe. Is this acceptable.

are the mains boards for each flat from one supply or are there 2 incoming suplys

the regs state that in each installation main protective bonding conductors complying with chapter 54 shall connect to the main earthing terminall , so following your question if the electrical supplys to the flats are seperate that would make two seperate installations so there for you would have to earth the gas back to the main earthing terminal , if the upstairs flat is a sub main from the down stairs then i suppose the you could argue its one installation then it would be ok.

 

[Des 56]

In each installation main protective bonding shall connect to the met
Where an installation serves more than 1 building the protective bonding to the gas should be applied to each building
This implies to me that whether there is seperate supplies or just the one then the gas earth should be installed for each flat from its own dist board to its own point of entry(not outside in the box)
I would remove the link so that the equipotential zones remain seperate and no I do not think it is acceptable

 

[coxy]

What are the mains supplies to the flats ??? pme ? If so are there 2 supplies ie 1 to upstairs 1 to downstairs ?
If 2 seperate supplies i agree no need for link.
If sub main to the top floor flat, does this still make the top floor flat a pme supply - i dont think so.Then different regs apply.You would need to look at the nic tech manual.

 

[Spudnik]

I would say that each flat should have its own MET and bonding to its own meters.

This would safe guard the second flat against lack of gas bonding should the first flat ever have the gas cut off and the meter removed.

 

[Guest123]

Hey.

The last block of flats I did, we ran seperate bonding conductors from each flat down to each gas meter in the basement, in 16mm just to be safe and also the same with the water services.

The services were also bonded at point of entry to each flat incase of any breaks in pipework at later date.

Overkill? maybe.