16mm T+E need for Dual earth?

Strickers · Nov 28, 2010

Hi Guys

I've done a periodic on a small office today in the cellar there is a switch fuse with a 16mm T+E feeding a DB on 2nd floor with 2 ccts for offices with computers and a lighting circuit. The office ccts will have high earth leakage from computers 10+ on each circuit. The DB should therefore have dual earth as rings for the computer ctts an be classed as code 4.

Any helps please guys

Deleted member 9648 · Nov 28, 2010

I could stand corrected here but I did not think that applied to distribution circuits...just finals...after all how far do you go? dual earths from the earth source to the MET?

IQ Electrical · Nov 28, 2010

Do you mean dual earth of the distribution circuit?
I'm not aware of any requirements for this and I would imagine that a distribution circuit cpc would be regarded as mechanically robust enough not to need duplication etc.

Remember that high integrity earthing is purely to increase mechanical integrity of the connection(s).

Des 56 · Nov 28, 2010

I think he means the computers circuit
If the leakage exceeds 10m/amp they require high integrity connection
If they are on a ring however and that ring is 2.5mm/1.5mm then the total area is 6 cores which together is 12mm it exceeds the size required (10mm total of all cores of a multi core cable,It just needs connecting as high integrity at the consumer

Oh sorry
I just re read the topic title,theres me waffling on about something I know little of and the title says 16m T+E for dusl earth