Garage Consumer unit query

[dann07]

I am installing a New C/U in the garage to run lights and sockets.
I also may want to add Outside lighting or Security lights in the future.

Is a 2 way garage unit ok for this expansion or should i buy a 3 or 4 way unit in anticipation of the future additions ?

Thanks.

 

[sparkyspike]

Firstly, a 2 way garage CU would normally be fine.

Secondly, there are many variables which would be a factor in the design.

Is your garage part of the house? Is there already a cable running into the garage? Is there an existing CU in the garage? What supply (type and capacity) do you have? Do you have RCD protection? What load will be on the garage sockets? What load will be on the outside lights? What is the current maximum demand on your property? Is the garage CU to run straight off the main supply, via a breaker in the main CU or from a switchfuse unit? What future additions do you anticipate?

etc etc etc

 

[dann07]

The Garage is detached and power is supplied from my house C/U from a 16A MCB on the 30mA RCD side of the unit.

Cable running to the garage is SWA (6mm i think) into an old power/junction box which needs changing.

I am only running 3 double sockets and 1 2way light circuit.
As i said, i may want to add Security and outside lights in the future.

Hop this helps.

 

[Lectrician]

The cost of a 2 way verse a 4 or 6 way is not huge (talking decent brands and not the ****e garage CU's).

 

[dann07]

Also another addition to my query.

The Consumer unit i buy (all be it 2way or 4way etc), do i have to buy a dedicated "Garage unit" like this one http://www.screwfix.com/prods/73324...ts/Wylex-2-Way-Metal-RCD-Garage-Consumer-Unit
Or can i buy a Metal enclosed one (with inbuilt 80mA RCD) and add my own MCB's ( 6a, 6a, 16a etc) ?

Thank You.

 

[Lectrician]

As your supply to your garage is already RCD protected, why do you want to add a second RCD? I think your 80mA is a typo, or you have miss read the mA rating for the maximum current rating.

If you are going to use a consumer unit with an RCD as the incommer, you would want to move the feed to it from the RCD side of your home CU to the non RCD side.

You would first need to ensure that the cable between the house CU and garage does not need RCD protection due to non armoured cable being buried in the wall etc.

 

[dann07]

Appologies, it should have read 80 Amp RCD.

I would rather not move the Feed to the Non RCD side.
The SWA is not protected, but clipped to outside walls, running down the side of my house.
So, would a regular Metal Clad Enclosure with the rated MCB's i stated be adequate ?
Like this one : http://www.tlc-direct.co.uk/Products/CPD04M.html

Thanks.

 

[Taylortwocities]

A metal one.

I your supply TT?

 

[dann07]

My house is supplied via standard TN-C-S

 

[Taylortwocities]

Aah, so a metal CU in the garage is OK then.

 

[dann07]

Right,
So a standard metal enclosure Unit, 3 or 4 way, no RCD (as it is on the RCD side of my household Unit) Will be ok for my needs ?

Lastly, i need a 6A for Lights, a 16A for Sockets and another 6A for My future external lights/security......Is this correct please ?

Thank you.

 

[dann07]

Quick question associated with my post.

Which is the better Make of Consumer unit and MCB to go for ?

Contactum
Wylex
MK
Volex
Crabtree
or another

?

OR Which to avoid ?


Thanks.

 

[flameport]

Contactum - cheap garbage
Wylex - good enough for most
MK - good but overpriced for what they are
Volex - cheapened version of Wylex
Crabtree - rubbish plug in style busbars

As for the lighting - a 6A circuit can have over 1300W of lights on it, all being used at the same time. It is highly unlikely you will need more than one, even with the outside lights added.

Another much easier and cheaper way is not to bother with a garage CU at all. If you have a 16A MCB for this circuit in the house, connect the sockets directly to the cable and add a 5A FCU for the lights.

 

[sparkyspike]

If you're getting a metal CU, then the Crabtree would probably be a Loadstar, which is fine. The Wylex and MK would also be fine. Contactum have gone bust, so don't bother with that one.

As most garage boards come with an RCD, you may as well not bother with those, but get a standard four way board and load it with the breakers you need, plus a couple of blanks.

 

[ban-all-sheds]

Am I the only one concerned that someone who asks the sorts of questions that dann07 asks, and has the beliefs that he does concerning RCD protection of SWA, may not be suitably equipped to be installing CUs?

Is your garage part of the house? Is there already a cable running into the garage? Is there an existing CU in the garage? What supply (type and capacity) do you have? Do you have RCD protection? What load will be on the garage sockets? What load will be on the outside lights? What is the current maximum demand on your property? Is the garage CU to run straight off the main supply, via a breaker in the main CU or from a switchfuse unit? What future additions do you anticipate?

etc etc etc

I'd like to add:

What factors have you considered in the design of the final circuits in the garage?

What testing do you plan to carry out before and after energising the garage CU?

Are you aware that this work is notifiable?

Cable running to the garage is SWA (6mm i think).

Shouldn't you be sure what it is?

My house is supplied via standard TN-C-S

Do you know that it will be OK to export the earth to the garage?