Hi all


First post here, so apologies if I make any faux pas


I have a query on comms rack bonding (design stage).


- Two fibre services incoming to a big warehouse plus copper lines entering to a 42U cabinet in a small comms room on first floor of an attached little office area.

- MET is in the warehouse itself, in a corner (630A TPN supply).

- Fibre links from there to 5No. satellite racks (12U) on warehouse walls, 

- Satellite racks feed CCTV and WIFI in warehouse

- Light comms equipment install in the racks only.

- Furthest rack 240m away from MET (260m from comms room).


My question is about earthing and bonding to BSEN 50310.


Am I right in thinking that each satellite cab is to have a 4mm g/y to a brass earth block adjacent (secondary bonding busbar) and then connection onto a 16mm conductor back to a primary bonding busbar which in turn connects to the MET? Am finding the standard a little confusing. 42U to have a 16mm connection?


I see a table about sizing based on distance, but is that applicable?


Sorry if I am being dense, but finding it hard to understand. Help would be appreciated or direction to a simplified resource.


Regards


Muhammad