Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Replies 6 replies
  • Subscribers 38 subscribers
  • Views 82 views
  • Users 0 members are here
Options
You may also be interested in

Adding a bonding conductor to an existing main earth terminal

Electron666

Hi do you need to isolate the supply to a commercial building to connect a 16mm2 bonding conductor to the MET in relation to BS 7671 or HSE?

It isn't something I can find explicit guidance on.

The MET is at the intake and separate to the main LV board.

It is easily accessible without coming into contact with L&N conductors connected to the main LV board.

The earthing system is either TN-S or TN-C-S.

Isolating the supply is possible if required but would be costly, require multiple companies attending out of hours and would need to be planned in well in advance due to it being a refrigerated / food storage facility.

I note all these reasons are inconvenience related which is secondary to health and safety. Therefore, I'm only asking if there is a method that is commonly used such as standing on rubber mats or wearing rated gloves etc that is considered safe and proportionate to the to the small task being carried out.

Thanks

Parents
  • 0

    When you isolate the supply, the earthing conductor and MET will remain connected to the DNO's earth.

    I would suggest that you put a clamp meter around the earthing conductor to check for any current there. You could also check that the MET is at Earth potential by applying a volt meter between it and a screwdriver in some convenient exposed earth.

    The MET is, presumably, just a lump of uninsulated brass, so again, no special precautions required when handling it. What you do not want to do is disconnect the earthing conductor accidentally.

Reply
  • 0

    When you isolate the supply, the earthing conductor and MET will remain connected to the DNO's earth.

    I would suggest that you put a clamp meter around the earthing conductor to check for any current there. You could also check that the MET is at Earth potential by applying a volt meter between it and a screwdriver in some convenient exposed earth.

    The MET is, presumably, just a lump of uninsulated brass, so again, no special precautions required when handling it. What you do not want to do is disconnect the earthing conductor accidentally.

Children
No Data

Community Rules & Guidelines