External RCD/sockets

You are quite right it is in theory an extension lead and it would fit a plug as i tried a connection test when i laid the cable in Entelle plastic ducting. I just want as much earthing protection as possible hence the consumer unit in the garage and an  rcd in the external sockets. 

RCD sockets and RCD fused connection units to BS 7288 are not currently recognized by BS 7671 for isolation or additional protection without upstream RCD protection and isolation.

Steve

Why don't you do a proper job and run a steel wire armour  cable or steel conduit to your garage supplied from a separate way on your consumer unit?

JP

There are quite few caveats…

1. BS 7671 (The wiring regs) doesn't recognise RCD sockets to BS 7288 as providing the required 30mA RCD additional protection required for sockets (you need to use RCDs to BS EN 61008, BS EN 61009 or BS EN 62423. The reasons behind this have been debated at length, and it might be that a BS 7288 device actually provides perfectly adequate protection, nevertheless such an approach can't be said (or more importantly certified) as meeting wiring regs.
2. RCD sockets only provide RCD protection to its own in-built socket. Anything directly connected to the back won't benefit from RCD protection at all (unlike the US version, there's no ‘after-RCD’ set of terminals to connect to).
3. The new consumer unit in the garage (plus the new circuits formed downstream) would make the job notifiable under building regulations … you can still do it yourself if you choose but should pre-notify your local building control dept (or equivalent) and pay the appropriate fee (usually several hundred pounds); otherwise you should be involving a member of one of the registered compentant persons schemes for part P.

   - Andy.

Steve Mc: 
I just want as much earthing protection as possible hence the consumer unit in the garage and an  rcd in the external sockets. 

A CU in the garage won't make a jot of difference to that.

Is the circuit RCD protected?

Are there any services (gas, water, oil) in the garage?

John, i totally agree and in normal circumstances would but the main consumer unit is at low level in a kitchen with laminate flooring and this will EVENTUALLY come up and a new consumer unit installed however currently i cant get a lead from it to the back of the house. 

Chris, Water in blue polypipe no gas or oil in the garage.

I may add that we have been here less than 12 months and temporarily making good some old and tired installations. Currently the garage is supplied with flexi twin and earth !!

I think if you are of the opinion that putting it on a plugtop therefore fused to 13A or less rather than say an FCU fused in a similar manner makes it become non notifiable with regards to Part P etc I`,m not sure that distinction would stand up if you are taken to task about it. Opinions might differ on that one

That's why I am asking advice ebee.. and I thank you all. !! I  will want it all certifying eventually and with as little mods as poss. the external RCD double socket will be fed from the ring main via a FCU  i'm just not sure whether to just plug the Garage connection  or to hard wire it to the external sockets? 

Steve Mc: 
 

That's why I am asking advice ebee.. and I thank you all. !! I  will want it all certifying eventually and with as little mods as poss. the external RCD double socket will be fed from the ring main via a FCU  i'm just not sure whether to just plug the Garage connection  or to hard wire it to the external sockets? 

Initially leave sufficient length of cable at the R.C.D. outside socket neatly coiled so that when the new consumer unit is installed it can be connected to that. I personally would use a steel wire armoured cable for the underground garden route, but your cable may well be protected from gardening damage if it runs under concrete or paving slabs for example. The underground cable route is best R.C.D. protected if it is not armoured  cable, for safety reasons.

Z.