Should garage have secondary consumer unit? + Best way to extend power from garage to shed?

[haggis999]

A dedicated 20A type C MCB located in the consumer unit in my house feeds power to my detached brick-built double garage via an underground armoured cable. This MCB is one of a group that is controlled by an 80A RCD.

There is no additional MCB protection within the garage. The incoming armoured cable simply connects to a fused spur, from which there are two output cables, one to feed a lighting circuit and one to feed a double 13A socket. I am assuming that this met all the regulations when the garage was built around 30 years ago.

I have three questions.

• Is my garage wiring still considered acceptable or should I really have a secondary consumer unit in the garage with separate MCBs for lighting and power?
• Would the answer to my first question be different if I wanted a second double 13A socket in the garage?
  
• What would be the best way to extend power from the garage to an adjacent wooden potting shed? I would want the shed to have lighting and one double 13A socket.

I will be getting a local sparky to do this work, but I want to be certain that he (or she!) does things in the correct manner.

 

[Pete999]

Yes Pete, we have him sussed out, he might think were Idiots but we have outed him, lol, I wasn't born yesterday.

Nor me.

 

[Pete999]

Yes Pete, we have him sussed out, he might think were Idiots but we have outed him, lol, I wasn't born yesterday.

Nor me. if we both carry on like this do you reckon we will both get outed?

 

[MDJ]

LOL, probably

 

[uksrevivor]

Haggis you seem to have given to much away here as no qualified electrician will attach an swa cable to the back of an existing socket in the shed. You have stated you have rewired your own houses before so the post stinks of you doing a DIY jobby on this and i dont think anyone will advise further but i might be wrong, i think the only advice from here is....
1 Support Pompey football club lol
2 Get a proper electrician in who will assess all the loads and test and inspect the installation before any work and will certify his work after completion as this is a notifiable installation.

 

[Deleted member 26818]

You say there is an FCU in the garage, is it an FCU or does it have a switch (SFCU)?
I would not extend the circuit from the socket in the garage, but from the supply side of the SFCU.
I would then use another SFCU in the potting shed to supply the light and the socket, same as in the garage.
Adding another socket in the garage would not be a problem.
This work would not require notification to Building Control.
Installing a CU in the garage however, would require notification.

 

[dksanders]

BTW, I found him via Checkatrade

ugh Checkatrade. You give them a cheque and you're on their register. They assume you're good at the outset and it's only if they get complaints about you will you go negative.

I've never know an electricity supplier check domestic wiring. At best the meter fitter will cast an eye over the intake and maybe the CU and comment on that but (no disrespect to them) most of them haven't a clue about the regs, best practice or how, regarding domestic wiring.

 

[dksanders]

This work would not require notification to Building Control.

Surely it would as that would be adding power to a new special location i.e. a different part of the garden.

 

[Taylortwocities]

Surely it would as that would be adding power to a new special location i.e. a different part of the garden.

You would think so, but in their wisdom they removed this from the notification regime a while ago.

ATM the only things that require notification are

• Electrical work in special locations (bathrooms, swimming pools, etc)
• New circuits (there’s an argument over what defines a new circuit)
• Change of new consumer unit

That’s it. Everything else you can do yourself providing the work complies with BR Part P.