mike

hi. ive been told than on the new regs that cables less than 50mm deep in the wall have to be rcd protected. does any know if this includes where you know there are cables like above switches. thanks

LukeScotty

isn't it, if the cables arent 50mm deep, then mechinical protect it, or rcd it or both. An electrician may know they could be cables above the switch, but what about a home owner drilling through the wall to hang his pants on?

If You Build It, They Will Come n If it aint broken don't fix it!

Cirrus

I've just seen the NIC DVD on this tomight and basically it says that if the cables are less than 50mm deep they must be RCD protected - UNLESS in trunking and then you do not have to place on an RCD

mike

really seems a bit over the top does any one konw what size rcd? hope its not 30ma

Cirrus

Yup - 30mA

Shakey

Basically:

buried cable less than 50mm deep:-

within safe zone:30mA

within safe zone WITH earthed metallic protection (SWA, earthed conduit - NOT capping) - no RCd required (for cables)

Outside safe zone: 30mA WITH earthed metallic protection

Outside safe zone: must be earthed metallic covering (not allowed without)

Of course, if the cables feed sockets of 20A of less for use by ordrinary persons, or bathroom electrics, or equipment outside equipotnetial zone: RCD 30mA

UNLESS specifically labelled socket (ie Freezer only)

surface mounted CABLES do not need RCD but of course the circuit they are supplying may do (as above, bathrooms etc)

Obviously this will pretty much 'bin' the 100mA protection against fire RCD for TT's as well!

mike

thanks for that, but what do you mean by safe zone?

Grae79

like the twilight zone but less weird...

safe zones extend horizontally & vertically from wiring accessories (sockets/switches), the width of the zone relates to the length/width of the applicable accessory.

also have a safe zone of 150mm (6") at the top and corners of walls.

mike

I see. if knowing the cables are not 50mm deep on a existing instalation, should i put in a rcd or just put in a rcbo on the circuit i workrd on?

Cirrus

Until June you don't have to do anything but when the 17th comes in then, you gotta do it.