Garage consumer unit

[Russdeebrown]

Hi,

Im new to this board and have a question.

I have recently had a garage built and the firm has fitted a consumer unit in it for the electrics. This has armoured cable running underground into the house to the consumer unit in the house. This has not been connected up yet as i have an extremely old consumer unit which needs to be replaced with a new one.

My question is that the consumer unit in the garage only has one RCD in it. Here they have connected up the wiring for the lighting and the plug points. Should these be going into one RCD or should there be two RCD's.

I ask as i have looked on screwfix direct and they have consumer units for garages which have two RCD's. The one i have is more like one which would be used for a shower or something like that.

Any idea's.

Thanks

Russell

 

[Adam_151]

Board with a 30ma as the incommer is probably easiest rather than messing around with split boards and having some circuits without RCD protection or differing levels of RCD protection unless you have a special reason to do otherwise

 

[Job_n_knock]

I cant see the point of putting in a RCD into a garage CU unless its directly built onto the side of the house. With a seperate garage, theres a cable leaving the house and as its inadvisable to fit 2 RCDs in conjunction with each other, this cable needs to be RCD protected. In my view I would fit a RCBO into the main CU to feed the garage board, which would be just a normal DP main switch CU. Anyone concur ?

 

[Spark123]

The only thing that normally needs RCD protected is any sockets reasonably expected to supply equipment outdoors. The armoured supply cable doesn't require RCD protection unless it is fed from a TT system or similar. In an ideal world they would use a normal two way (or larger) CU with a 6A MCB for lights and a 32A/20A RCBO for sockets. A CU with an RCD incomer and a 6A MCB and a 32A/20A MCB is acceptable, just the lights will be lost in the event of an earth fault.

 

[Job_n_knock]

Fair enough

 

[JohnD]

... the consumer unit in the garage only has one RCD in it.

Just to check, you do mean RCD not MCB?

 

[ban-all-sheds]

My question is that the consumer unit in the garage only has one RCD in it. Here they have connected up the wiring for the lighting and the plug points. Should these be going into one RCD or should there be two RCD's.

I ask as i have looked on screwfix direct and they have consumer units for garages which have two RCD's. The one i have is more like one which would be used for a shower or something like that.

I'm not entirely convinced that you know the difference between RCDs and MCBs....

 

[Russdeebrown]

The fuse says that it is a Multi 9 RCCB. Does that mean anything?

 

[Russdeebrown]

I'm not entirely convinced that you know the difference between RCDs and MCBs....

I dont... Thats why im asking you guys........

 

[JohnD]

You should have got:

A consumer unit being the plastic box

A main switch that might be two inches wide (it will be twice as wide as the other things). It might be marked ON/OFF 100Amp or 80Amp or 63Amp. Additionally, it might have a Test Button on it and say in small text "Press Test quarterly" and "30mA" or similar. If it has these additional things then it is an RCD. In a house you might have both a Main Switch and an RCD but this would be very unusual in a garage.

You should then also have one or more things that look like switches, and are about three quarters of an inch wide. They will be marked "B32" "B06" or similar.

What do you see in your CU?

Here is a typical garage CU with an RCD fitted and two MCBs beside it.

This is a spare RCD

(a main switch like this

is the same size)

and here is a typical MCB - you will notice it is half the size

 

[Spark123]

Hang your head in shame JohnD , no picture of an RCBO!!!!

 

[Steve]

Hang your head in shame JohnD , no picture of an RCBO!!!!

i expect he didnt want to confuse the OP

 

[Spark123]

I'm surprised the links wern't to pictures of mem ones though

 

[JohnD]

I guessed it was a cheapo job