Earth bonding on old Gas pipe or move to new?

Discussion in 'Electricians' Talk' started by Just_Ali, Jun 4, 2021.

  1. Just_Ali

    Just_Ali New Member

    Hi, I’m new and I wonder if anyone can help me and advise me what I need to do. I’m not sure if this is needed but I think I may need to move or add a new earth bonding to the gas pipe to CU. We are on the 5th floor and from what I was told our Gas meter was moved from inside the kitchen to the balcony outside but the earth bonding was never moved. From what I can see the earth bonding is still on the old gas pipe in the kitchen where the meter was and entering the flat and the pipe is still live but capped. Not sure what the council did when it was move but it looks like the pipes are still connected somewhere in the basement or the building. If I turn the gas supply off from the new meter the supply to the old pipe gets shut as well, the reason I know this it’s because last year we wanted to remove this old pipes and realized it was still live with gas and we could shut the supply off from the balcony.

    So the question, do I need to move earth bonding to the meter outside and place it where it enters the building or will the current earth bonding be ok as it is or join them together?

    Any help and advice would be great.
  2. Bazza

    Bazza Screwfix Select

    The bonding can be at the point of entry to the building.

    the regulation says
    “…. Where practicable the connection shall be made within 600 mm of the meter outlet union or at the point of entry to the building if the meter is external…”

    Also, if the new incoming service is plastic, or there is a plastic insert, then bonding may not be required at all.

    There’s a comprehensive guide here
  3. Bob Rathbone

    Bob Rathbone Screwfix Select

    If you are a tenant, it is not your place to mess with it, leave it be.
  4. Just_Ali

    Just_Ali New Member

    Hi, this is ex-council flat and we the leaseholder so the responsibility falls to us.
    The new pipes are copper I believe it's 22m but the old gas pipe is a bit big looks like 40m and copper as well.
    So since both pipes are entering the building in kitchen, the old one near the door and closer to the CU and the new one in the back of the kitchen next to the balcony outside. Leaving the bonding on the old gas pipes should be fine?
  5. Bazza

    Bazza Screwfix Select

    No, the bonding needs to be moved to the new pipe. The old one does not require bonding if nothing is connected to it.
  6. Just_Ali

    Just_Ali New Member

    This where I am a bit coufused. The old pipe has nothing connected but it still live and has Gas to feed into but just capped off.
  7. Bazza

    Bazza Screwfix Select

    Why confused?

    Old pipe is not connected to any other pipe work so cannot “import” an earth potential to the property. The new pipe is connected to your internal pipe work and could “import” an earth potential to the property.

    I think you are misunderstanding the requirement for bonding. It is not there to provide an earth for the property. It us there to ensure that all of the copper pipes in the flat are at the same potential.
    Dan Greenslade likes this.
  8. Dan Greenslade

    Dan Greenslade Active Member

    Well put. Easy mistake to make unless you know about it though..
  9. teabreak

    teabreak Screwfix Select

    What will happen if a damaged live wire touches that old pipe under the floor? Seems sensible to have it earthed so the fuse will blow or breaker trip immediately, rather than waiting till someone comes along and touches the pipe and provides a path to earth that way.
  10. Bazza

    Bazza Screwfix Select

    Think about it. There are two options:
    1. If the gas pipe isn’t actually metal, then nothing will happen.
    2. If the gas pipe is metal, it will already be earthed - the pipe is buried in the ground!
    then when the live cable touches it the fuse protecting the random live cable with blow or the MCB and/or the RCD will trip.

    Are there any other unlikely issues you can imagine?
  11. Just_Ali

    Just_Ali New Member

    Hi Bazza, thanks for all the advice the reason I am a bit confused is because the old pipes still connected to new pipes somewhere in the building it could be the basement or the roof. We live in the 5th floor flat so the pipes are coming from the floor but below us, if another flat so I don't know if its run thought the flat below as well.
  12. teabreak

    teabreak Screwfix Select

    Yup! All gas pipes in a building are metal, plastic not allowed, many outside services to existing iron risers are re-laid in plastic so no earth . At some point the service riser may well be disconnected as it should have been because it is an invitation to theft. I expect there was a good reason to move it possibly to replace an internal riser with an external one on a tall block of flats. The supplier should be informed it is still live.

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