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Main Protective Bonding to incoming Gas and Water services

Hello,

My query is in reference to regulation 411.3.1.2. 

It is in relation to a project where we have a block of flats where we have a new proposed pumped water supply and an existing Gas supply both either sleeved or installed in poly existing the ground externally to the building. This is then connected to steel/copper pipework run externally up the outside of the block spurring off at each level into domestic properties. Where the meter is located and then onto the domestic installation.

There is a difference in opinion between Client and Contractor parties in relation to the need to bond these pipes after the meter/stopcock positions. The Contractor is disputing the need to install equipotential protective bonding at the point of entry (after the meter/stopcock) within each domestic property, as they believe that because the pipework coming out the ground is not extraneous material, they don’t have to bond it.

The Consultant designing and tendering the project neglected to provide any instruction either way.

The other interpretation sits around the specific words “entering the building” and “at their point of entry” within Regulation 411.3.1.2, which could be considered to be in line with each flat being its own “equipotential zone”, and therefore individual buildings, and that there is a possibility of exporting a potential from one flat into another flat, if those installations are not fully installed to recent versions BS7671, which in this case is very likely, as there are a significant number of leasehold properties within the blocks where most of the electrical installations within, date back to the 1960/70’s. There is also the fact that within most of the properties main protective bonding is already in place (apart from the new water supply).

Any assistance is appreciated.

Parents
  • Hi HMREES, the Gas Industry Unsafe situations Procedure, to be found here IGEM/G/11 Edition 2 - Gas industry unsafe situations procedure - IGEM says;

    "3.3.2 Equipotential Bonding Electrical Safety Issue Regulation 18(2) of GSIUR places a duty on gas engineers to notify the responsible person that equipotential bonding may need to be connected to gas installations in domestic premises. Note: Where non-metallic (non-conductive e.g.PE) service pipes/service pipelines enter the building and are then connected to metallic pipes within the building, the metallic pipes within the building do not require protective bonding. Where required the purpose of equipotential bonding is to ensure the gas installation, other metallic services and parts within the premise remain safe under electrical fault conditions. Where bonding is necessary it should preferably be connected: within 600 mm of the outlet of the gas meter, before any branch, or  where the meter is fitted outside the building, as near to the point of each entry of the pipework, inside the building, before any branch. Where a gas engineer cannot confirm that adequate bonding arrangements where necessary, exist, HSE guidance is that the responsible person be notified in writing of the requirement for equipotential bonding. This can be achieved by leaving a bonding notice as described in BS 6891, which advises that the bonding be checked/carried out by an electrically competent person."

    So it is not a fail, and only requires a notice.

    Edit; You could provide your own notices at gas meters to state that bonding is not required and giving the reason why

Reply
  • Hi HMREES, the Gas Industry Unsafe situations Procedure, to be found here IGEM/G/11 Edition 2 - Gas industry unsafe situations procedure - IGEM says;

    "3.3.2 Equipotential Bonding Electrical Safety Issue Regulation 18(2) of GSIUR places a duty on gas engineers to notify the responsible person that equipotential bonding may need to be connected to gas installations in domestic premises. Note: Where non-metallic (non-conductive e.g.PE) service pipes/service pipelines enter the building and are then connected to metallic pipes within the building, the metallic pipes within the building do not require protective bonding. Where required the purpose of equipotential bonding is to ensure the gas installation, other metallic services and parts within the premise remain safe under electrical fault conditions. Where bonding is necessary it should preferably be connected: within 600 mm of the outlet of the gas meter, before any branch, or  where the meter is fitted outside the building, as near to the point of each entry of the pipework, inside the building, before any branch. Where a gas engineer cannot confirm that adequate bonding arrangements where necessary, exist, HSE guidance is that the responsible person be notified in writing of the requirement for equipotential bonding. This can be achieved by leaving a bonding notice as described in BS 6891, which advises that the bonding be checked/carried out by an electrically competent person."

    So it is not a fail, and only requires a notice.

    Edit; You could provide your own notices at gas meters to state that bonding is not required and giving the reason why

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