Consumer unit installation help

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Mckie D.I.Y

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Hello there was just wondering if anyone could help, I was contemplating fitting a Garage CU in my shed which is supplied with a double socket by a BS5467 SWA cable off a fused spur rated 13 amps ( not my work was like that when I moved in )  which is on a 32amp Mcb, the consumer unit has a 6 amp and 32amp mcb and 40 amp (30mA) rcd and I was going to put two double sockets and a light fixture for now, my question is does anybody see anything wrong with what im Proposing to do ? Like I know it won’t trip at the main board because the fuse will just blow at the spur but I only have 13 amps to play with and I already have a tumble dryer and fridge in there, now I was also thinking of replacing that fused spur with a 45 amp

cooker switch so it would trip at the main mcb instead of blowing a fuse at the spur but that was just a thought but if anyone could give any feedback, thoughts or opinions it would be greatly appreciated but bear in mind I have not actually done any of this idea yet hence why the question so please don’t shoot me :)  

thank you  

 
Like I know it won’t trip at the main board because the fuse will just blow at the spur but I only have 13 amps to play with and I already have a tumble dryer and fridge in there, now I was also thinking of replacing that fused spur with a 45 amp cooker switch so it would trip at the main mcb instead of blowing a fuse at the spur but that was just a thought but if anyone could give any feedback, thoughts or opinions it would be greatly appreciated but bear in mind I have not actually done any of this idea yet hence why the question so please don’t shoot me :)  

thank you  


not a good idea, and against the regs. 

The 13A fuse is there to limit the load and protect the cables.

Removing the 13A fuse and replacing it with a 45A switch will present a potential fire hazard

Sorry if this isn't what you want to hear

 
not a good idea, and against the regs. 

The 13A fuse is there to limit the load and protect the cables.

Removing the 13A fuse and replacing it with a 45A switch will present a potential fire hazard

Sorry if this isn't what you want to hear
It’s no problem I’m here asking for help so I don’t wanna do anything to pose a danger, so if I just left the fused spur in and did the installation of the consumer unit and fitted a light and two double Sockets from it would I be breaking any regs or laws ? Thanks in advance For your time and feedback 

 
It’s no problem I’m here asking for help so I don’t wanna do anything to pose a danger, so if I just left the fused spur in and did the installation of the consumer unit and fitted a light and two double Sockets from it would I be breaking any regs or laws ? Thanks in advance For your time and feedback 


If you are in England or Wales the fuseboard and circuits fall under Part P of the building regs

 
Fitting a "shed" CU on the end of a cable that is supplied from a 13A spur off a house socket circuit, is just a waste of time, money and space IMHO..

(bit like using an umbrella indoors when its raining outside...   

or wearing a crash helmet while walking the dog!

whilst neither will do any harm.. they are both completely pointless)

It will not allow anymore protection or capacity as this is limited by the circuit it is supplied from..

It will be pot luck if the House RCD or Shed RCD trips first.

A 32A MCB from a 13A cartridge fuse will be useless

a 6A MCB from a 13A cartridge fuse possibly may have occasional functionality.. 

All you need is a 5A or 3A fused spur in the shed for the lights..

the rest of the sockets can just stay supplied from the 13A spur feeding the whole shed..

A cables capacity is limited by its physical construction, length and installation method.

Fuses are selected to protect the cable from overload damage.

You cannot just randomly remove or replace fuses without confirming the cables connected have sufficient capacity..

You have not told us what size your shed cable is or how long it is..

so its impossible to guess what options you may or may not have to alter the supply capacity to the shed..

 
Fitting a "shed" CU on the end of a cable that is supplied from a 13A spur off a house socket circuit, is just a waste of time, money and space IMHO..

(bit like using an umbrella indoors when its raining outside...   

or wearing a crash helmet while walking the dog!

whilst neither will do any harm.. they are both completely pointless)

It will not allow anymore protection or capacity as this is limited by the circuit it is supplied from..

It will be pot luck if the House RCD or Shed RCD trips first.

A 32A MCB from a 13A cartridge fuse will be useless

a 6A MCB from a 13A cartridge fuse possibly may have occasional functionality.. 

All you need is a 5A or 3A fused spur in the shed for the lights..

the rest of the sockets can just stay supplied from the 13A spur feeding the whole shed..

A cables capacity is limited by its physical construction, length and installation method.

Fuses are selected to protect the cable from overload damage.

You cannot just randomly remove or replace fuses without confirming the cables connected have sufficient capacity..

You have not told us what size your shed cable is or how long it is..

so its impossible to guess what options you may or may not have to alter the supply capacity to the shed..
 
okay I appreciate the feedback thanks for

your time I’ll just go with doing the fused 

spur option seems easier :)  

 
if you know the size of the cable, you could replace fused spur with a 16A or 20A MCB, giving a bit of head room for running tumble drier and other things at the same time. BUT, cable has to be man enough to take that loading.

 
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