Help wiring Garage Consumer Unit

[midiman]

Hi, please can you see if this is correct for what I am trying to do.

I want 1 ring main circuit for sockets and another for lighting.

This is for a test lab that I am setting up at home.

The CU didn't come with any instruction so I want to make sure that I am doing it right and using the correct cabling.

Here is a picture :



Thanks

 

[buzzlightyear]

This is for a test lab that I am setting up at home.

can you not ask rattus rattus for help at your house!

 

[Pete999]

Hi, please can you see if this is correct for what I am trying to do.

I want 1 ring main circuit for sockets and another for lighting.

This is for a test lab that I am setting up at home.

The CU didn't come with any instruction so I want to make sure that I am doing it right and using the correct cabling.

Here is a picture :

View attachment 39393

Thanks

Why would you want a lighting ring? a radial circuit would be the best option for a lighting circuit, and I suggest 1.5mm2 for the lights, not 2.5mm2, just saying.

 

[Taylortwocities]

Where does the 2.5mm cable that provides the main feed in come from?

 

[buzzlightyear]

Why would you want a lighting ring? a radial circuit would be the best option for a lighting circuit, and I suggest 1.5mm2 for the lights, not 2.5mm2, just saying.

or is it pete999. building a extension calling it a test lab!

 

[Pete999]

Why would you want a lighting ring? a radial circuit would be the best option for a lighting circuit, and I suggest 1.5mm2 for the lights, not 2.5mm2, just saying.

Got a suspicion the OP is the same chap that said the college he attended used a PSU.

 

[Pete999]

or is it pete999. building a extension calling it a test lab!

What with my knees and back? no chance.

 

[midiman]

Why would you want a lighting ring? a radial circuit would be the best option for a lighting circuit, and I suggest 1.5mm2 for the lights, not 2.5mm2, just saying.

Sorry it was just the way I worded it.

I want 1 main ring for the sockets and another being a radial for the lighting.

Some people say 1mm is adequate for lighting but I don't mind using 1.5mm if I have to.

The feed to the CU is coming from a 13a plug as per the discussion we have the other week about setting up my lab.

Thanks

 

[l4urence]

Why put a ring anyway - designed decades ago, old hat. I would consider radial sockets in 2.5 but you must replace the 32A MCB with 20A; design depends on the required socket load. As Pete999 states 1.5 for the lights, also in radial.

 

[Pete999]

Sorry it was just the way I worded it.

I want 1 main ring for and another being a radial for the lighting.

Some people say 1mm is adequate for lighting but I don't mind using 1.5mm if I have to.

The feed to the CU is coming from a 13a plug.

Thanks

Use a flex, rather than twin and earth cable for the supply cable, 13 amp plug tops are not designed to accept twin and earth cable.

 

[buzzlightyear]

Why put a ring anyway - designed decades ago, old hat. I would consider radial sockets in 2.5 but you must replace the 32A MCB with 20A; design depends on the required socket load. As Pete999 states 1.5 for the lights, also in radial.

next .he will tell us that he is putting in
a cooker circuit!

 

[Taylortwocities]

The feed to the CU is coming from a 13a plug.

So, what you have planned is totally pointless.
The circuit protection is on the 13A plug, so the 32A MCB in the garage will never ever in a million years trip because the maximum current will only ever be no more than 13amp.

So there is no point having a ring final, again because the current is limited to 13A.
Also I expect that the socket that the plug is in (at the house end?) is already RCD-protected? So there's no point in the RCD in the garage either.

So you could have saved your money on that garage unit, just run in the cable to a string of sockets and used a £3 FCU to provide the light switch and feed.

 

[Pete999]

So, what you have planned is totally pointless.
The circuit protection is on the 13A plug, so the 32A MCB in the garage will never ever in a million years trip because the maximum current will only ever be no more than 13amp.

So there is no point having a ring final, again because the current is limited to 13A.
Also I expect that the socket that the plug is in (at the house end?) is already RCD-protected? So there's no point in the RCD in the garage either.

So you could have saved your money on that garage unit, just run in the cable to a string of sockets and used a £3 FCU to provide the light switch and feed.

I think the OP intends to build a testing board, to practice his ability for carrying out tests, it's not an ideal scenario, but I guess he will have account for the discrepancies, at least I think that's what he intends to do, but then again in this mad world of DIY electrics, who knows?

 

[midiman]

Use a flex, rather than twin and earth cable for the supply cable, 13 amp plug tops are not designed to accept twin and earth cable.

Thanks I will pickup some better cabling.

1.5mm for the lighting and some flex for the mains.

 

[Pete999]

Thanks I will pickup some better cabling.

1.5mm for the lighting and some flex for the mains.

Yes it is the same member just checked,

 

[midiman]

I think the OP intends to build a testing board, to practice his ability for carrying out tests, it's not an ideal scenario, but I guess he will have account for the discrepancies, at least I think that's what he intends to do, but then again in this mad world of DIY electrics, who knows?

As mentioned in a previous post. It's only for setting up a test lab for a couple of sockets and lights on a board!!

I'm fairly sure I stated that this is for a test lab. Sorry if some of you misunderstood my intentions.

I just want to make sure that I am using the right cabling.

 

[buzzlightyear]

I wish some people would come clean about their intentions!

 

[Richard Burns]

As a test arrangement you have the wires going to the correct positions.
On the negative side live testing at this unit will involve your incoming supply unless it comes from a separated source.
As has been said your total load will be limited to the plug fuse rating and flex (up to 1.5mm²) should be used for the connection into the plug. Ideally the ends of the flex in the consumer unit should have ferrules on to ensure a safe connection into the screwed terminals without damaging the fine stranded cable.
As a design a 2.5mm² cable can only take 27A in the best circumstances and so cannot be protected by a 32A MCB, 25A at a pinch, 20A generally.
A consumer unit should not ideally have two different manufacturers protective devices as they may not line up correctly and so cause weak spots and high resistances at the busbar.
It starts off so easily doesn't it!

 

[Pete999]

As a test arrangement you have the wires going to the correct positions.
On the negative side live testing at this unit will involve your incoming supply unless it comes from a separated source.
As has been said your total load will be limited to the plug fuse rating and flex (up to 1.5mm²) should be used for the connection into the plug. Ideally the ends of the flex in the consumer unit should have ferrules on to ensure a safe connection into the screwed terminals without damaging the fine stranded cable.
As a design a 2.5mm² cable can only take 27A in the best circumstances and so cannot be protected by a 32A MCB, 25A at a pinch, 20A generally.
A consumer unit should not ideally have two different manufacturers protective devices as they may not line up correctly and so cause weak spots and high resistances at the busbar.
It starts off so easily doesn't it!

Well spotted never noticed that, you are however right of course.

 

[Octopus]

And using an up front RCD won't comply with the regs ..........