MEN link with 2 control boxes

[regedit]

See diagram re supply to 6+6 rooms in 2 seperate buildings. Should there be MEN links in Control Box B and CUs B1-B6?

 

To explain, Electrician has made MEN links in Control Box A and all Consumer Units A1 to A6 (1 CU per room). Control Box B just added by new electrician but he didn't make a MEN link in it nor in the CUs B1-B6. Both Control Boxes have their own earth rod and the boxes and rods are 20 meters apart.

 

Should there be MEN links in Control Box B and/or CUs B1-6 ?

 

Thanks.

[Crossy]

You should have only one N-E link per installation, and it should be at the supply inlet. You can call each building an installation, so put a MEN and a rod at each control box.

 

The CUs in rooms A1-A6 shouldn't have links. I'm assuming here that their earth is distributed from Control Box A. Having those extra N-E links isn't going to be a danger but it's not to code and if you have RCD/RCBO in Control Box A then you may have issues with them constantly tripping.

 

The CUs in rooms B1-B6 don't need links. I'm again assuming here that their earth is distributed from Control Box B (which should have a MEN).

 

 

[regedit]

Thanks - that makes sense.