Should I install an RCD when replacing multi socket in garage?

mark_cycling00

Currently an electricity cable enters the garage from the ground, hits a heavy duty looking fuse and switch, then two wires exit from here 

One wire supplies two exterior lights.
The other wire goes to a single socket that is used for a freezer.

I'd really like to change to a multi socket so I can use a power tool occasionally and still have the freezer on. 

Power tools are a bit risky so I wondered if I should install something like a 13a RCD at 13a before the multi socket.

The current setup for the whole house passed an electrical inspection about 5 years ago. 

Many thanks if you can advise 

flashg67

Not an electrician, but with power tools outside, I always like to add an rcd. You can get plug in ones quite cheaply or one built into a double socket - eg Screwfix item 3133J

Jonboy_1984

Does it run back to your house internal consumer unit and is that rcd protected?

mark_cycling00

Jonboy_1984 said:

Does it run back to your house internal consumer unit and is that rcd protected?

.on the consumer unit (the modern type with flip switches) there is a "garage" labelled fuse.

I was thinking that it might be worth protecting the freezer and rather than the whole circuit cutting out

TadleyBaggie

mark_cycling00 said:

Jonboy_1984 said:

Does it run back to your house internal consumer unit and is that rcd protected?

.on the consumer unit (the modern type with flip switches) there is a "garage" labelled fuse.

I was thinking that it might be worth protecting the freezer and rather than the whole circuit cutting out

Having flip switches means very little, I have a board full of these and not a single RCD. Other boards may have a couple of RCDs protecting mutilple circuits. Others may have just RCBOs where each circuit is protected for current and leakage.

FreeBear

All sockets that could be used with an extension lead outside should be RCD protected - Hopefully you are using metal clad sockets in the garage, in which case, use one like this - https://www.screwfix.com/p/british-general-13a-2-gang-sp-switched-metal-clad-passive-rcd-socket-with-white-inserts/4714p

mark_cycling00

That's a great answer. I haven't purchased anything yet so will get those.
Thanks 

Risteard

FreeBear said:

All sockets that could be used with an extension lead outside should be RCD protected - Hopefully you are using metal clad sockets in the garage, in which case, use one like this - https://www.screwfix.com/p/british-general-13a-2-gang-sp-switched-metal-clad-passive-rcd-socket-with-white-inserts/4714p

All socket-outlets everywhere should be RCD protected.

Rodders53

FreeBear said:
Hopefully you are using metal clad sockets in the garage,

Why?
There's rarely a need to in most domestic garages. 
Only IF the sockets could be subject to impact damage in a 'workshop' style use would they become advisable. 

All the sockets, switches and heating wiring stuff in my attached garage are plastic... even the Consumer unit and that's from new when built.

Chickereeeee

mark_cycling00 said:

Jonboy_1984 said:

Does it run back to your house internal consumer unit and is that rcd protected?

.on the consumer unit (the modern type with flip switches) there is a "garage" labelled fuse.

I was thinking that it might be worth protecting the freezer and rather than the whole circuit cutting out

IF the 'switches' are RCBOs, or the circuit is otherwise protected by RCD, then a) you don't need another RCD in the  garage and b) an RCD in the garage will not necceessarily prevent the one in the CU from tripping. 

mark_cycling00

Thanks for the replies it's a great learning experience.

If sounds like I could check to see if my consumer unit has RCBOs target than just fuses. If they are RCBOs then the circuit might be "safe"

The scenario I'm not sure about yet is as follows: if something dangerous happens to a power tool eg drill through a live wire. Will the entire garage circuit be affected? I'm just concerned about keeping the freezer working in this scenario 

Will a metal socket with built in RCD help at all?

Thanks