Good evening gurus!!
We have a new installation on a farm with parlour, associated equipment and offices.
The supply is 400a three phase with PME and it is in the main plant room in the middle of building where our distribution will be located.
With it being a farm we obviously need to have RCD protection (TD 300mA). We plan to split it over a couple of Hager Hybrid boards as we have a couple of large outgoing loads, but as they do not offer RCD TD incomer, we will be fitting two of the Hager 200a RCD enclosures and devices before the boards.
We will need to have a panel board to feed the three boards (third is a small 12way 100a with TD for lighting and small power). My issue is separating the PME and TT as both in same room and we can not relocate the incoming supply.
My thoughts first were to install the 6way panel board next to the incoming supply (400a tp switch fuse in place also) and leave this on PME. Then feed the sub boards and have these on TT. I will need to separate the systems so will need to have a break in the metal trunking. Will I also need to fully enclose the incoming supply and panel board so you can not touch both PME board and TT boards at the same time? Or do I install an upfront RCD protecting everything?
it’s a tricky one as usually the supplies are away from parlours etc so can easily achieve the TT with no risk of PME in same building.
im concerned with having a main RCD straight out the SSE supply covering the whole installation.
