Where to bond and from which supply?

[dobo99]

Hi been scratching my head on this for a couple of days now.

Situation is this, doing a rewire of a church with living accomodation attached, the church itself has been rewired now onto the living accomodation. There are a total of three boilers providing CH/HW to the church and house, a big floor mounted one which does the church only, a normal size floor mounted one which does part of the house and also some of the side room`s off the church and finally a back boiler which does the rest of the house.

Problem i have is the Gas main comes in off the road to a large meter which is mounted on the community centre wall which is about 20M from the church and is completely seperated (ie not attached to the church) then it goes underground again and reappears in two seperate places a largeish steel pipe goes into the boiler house to feed the large floor mounted boiler and also a 28mm copper appears about 10m away from the steel pipe (the joint is not visible) and feeds the normal sized boiler, the back boiler and oven.

There are two seperate single phase T-N-S supplies one feeds all of the church/offices and the other does the house.

Question i have is where to bond the gas mains and off which supply? It`s got me stumped

Hope someone can help me

 

[ktguk]

i`d bond to both boilers, cover your arse by taking the potentiel out of them 100%, just write on test form earth at boiler for the "where not obvious" part.

 

[green-hornet]

I can see your confusion.

The ideal way is to bond from each supply to the main water and gas.

You should bond within 600mm of the supply entering the house.

There is no problem with shared bonding ie one main bond being connected to a seperate supply as this often happens in homes of multiple occupancy HMO's.

Each cu or dist board can then be fully inspected and will show bonding in place.

 

[dobo99]

Thanks guys thats kind of what i thought, it`s just a weird set-up and has confused me