Isolator or RCD main switch

what type of cable are you using and how are intending to run it as that will have a bearing on if you need rcd protection or not.

 

More info required:

1. Approx length of run from meter to CU.
2. Reference method used, i.e will the cable be buried in plaster, clipped direct, or conduit.
3. Is there a possibility of using other tyupes of cable? SWA, HiTuff etc

 

Is it not possible to wire the 6mm direct from the CU?

I'm under the impression that since the cable is not less than 50mm than it requires RCD protection.

 

An RCD main incomer does not offer over-current protection, this is merely the max rating of RCD. You will need to an MCB along side this to act as the over-current device. This was brought up when someone installed a 40A RCD 'shower switch' as a supply for their shower.

 

What does 6mm2 PC mean Mr Jenks?

 

I think he means cpc.

 

The cable is being clipped direct so there is no need specifically for it to be RCD protected for the reason Jitender gave.. Regardless of length of run cable size ect ect.. What type of supply do you have? TT PME?

I wouldn't worry about running a separate earth along with the 6mm either

 

Circuits of special locations require RCD protection.
Cables concealed in walls require additional protection, RCD protection being one of a number of options.
Socket-outlets less than 20A, and intended for general use require RCD protection.
As such, if the Sub Main is not concealed in a wall, does not pass through a location containing a bath or shower, then there is no requirement for RCD protection.

 

Unless it's a TT system Spin.

 

Even with TT installations, there is no requirement to provide RCD protection.

 

I think there is for a TT sub-main isn't there Spin?

 

No.
There is a requirement to provide fault protection, which could be by use of an RCD.
The most common method used in TT systems for mains and sub mains is double insulation.

 

I think you are getting confused somewhere along the line Spin.. In a TT installation every circuit must be protected by an RCD or fuse. Since you cant guarantee a good Zs the only option I to use a correctly rated RCD. For a submain installed as described above on a TT would be a 100ma TD. But since its not a TT then an isolator and fuse will be fine.

 

Thanks Caddy, that's the way I understand it,