External Power

[AP1984]

Hi,

New to the forum but fairly competent DIY enthusiast.

I have recently moved into a house which already has an external circuit in the basement (protected by a circuit breaker, max load 40a) powering 4 external double sockets, this is run off the main RCD protected circuit board for the house.

I also have a currently unpowered detached garage about 30m from my house which I'd like to run power too, just a simple tube light and a couple of sockets for a small heater and general power tool usage, possibly some basic gym equipment in future. I am also about to start building a pond so would like another double socket in the garden about 15m from the house to run a UV pond filter and pump.

So, my question is - can I simply run an external fused spur off one of the existing sockets that can power both the pond requirements and then a spur from that socket running to the garage? Do I need another fused switch after the socket in the garage to run to the light switch?

Planning to do all outdoor power runs in SWA clipped to fence.

Is the above acceptable, or could you give me a better way of doing things?

Thanks, in advance!

 

[telectrix]

always better to feed any outbuildings direct from main CU on a dedicated circuit. that way, a fault in the outbuilding/s will not affect the house.

 

[Spoon]

Also, so add to the above, a fused spur will only give you a max of 13A.
Running a heater, hand tools and a pond pump may go over this.

The disadvantage of making it a dedicated circuit is that this will fall under Part P and your local building control will have to be notified. This costs money.

Oh, and welcome to the forum mate...

 

[Dustydazzler]

Cheap option is to take a 2.5 spur of the existing circuit and use a 13a swi spur to feed your new out door setup. This could be done in 2.5 armoured or even 1.5 VD permitting

Expensive option is to run a brand new circuit to the garage via a sub main from the existing board

 

[AP1984]

Also, so add to the above, a fused spur will only give you a max of 13A.
Running a heater, hand tools and a pond pump may go over this.

The disadvantage of making it a dedicated circuit is that this will fall under Part P and your local building control will have to be notified. This costs money.

Oh, and welcome to the forum mate...

Cheers, what

Cheap option is to take a 2.5 spur of the existing circuit and use a 13a swi spur to feed your new out door setup. This could be done in 2.5 armoured or even 1.5 VD permitting

Expensive option is to run a brand new circuit to the garage via a sub main from the existing board

Hi, thanks. That's sort of what I was suggesting. So switch spur before the socket for the pond then spur off from that for the power to the garage?

Alternatively, if 13a won't handle the power to both the pond and the garage could I spur of separately from a different socket? I have two double sockets outside no more than 5m apart so that's doable.

 

[Andy78]

Cheers, what


Hi, thanks. That's sort of what I was suggesting. So switch spur before the socket for the pond then spur off from that for the power to the garage?

Alternatively, if 13a won't handle the power to both the pond and the garage could I spur of separately from a different socket? I have two double sockets outside no more than 5m apart so that's doable.

No you can't spur off a standard socket circuit for multiple outlets without fusing down to 13A.

 

[MJPD29]

Hi, a bit worrying that the sockets in your basement are run off a 40a mcb. Are you sure this is the case? And what size of cable is it?

 

[AP1984]

No you can't spur off a standard socket circuit for multiple outlets without fusing down to 13A.

But on different spurs the combined ampage from the pond and the garage would be split, so would solve the issue of 13amp not being enough for both via one spur? Or am I missing something?

 

[Dustydazzler]

Yes so long as you have a ring you can spur off one socket and spur another of a different socket

 

[AP1984]

Hi, a bit worrying that the sockets in your basement are run off a 40a mcb. Are you sure this is the case? And what size of cable is it?

The basement has it's own circuit panel - the max load stated on the labelling in 40a. That's via SWA from the main house board (as it runs out of the house, around the building and back down into the basement). This feeds 4 external double sockets via 1.5mm cable.

 

[Andy78]

But on different spurs the combined ampage from the pond and the garage would be split, so would solve the issue of 13amp not being enough for both via one spur? Or am I missing something?

Well you could I suppose. It's not the way I'd go about things though. Do you have the correct test equipment to prove your circuit alterations are safe and have the correct knowledge to perform this work in accordance with the wiring regulations ?

 

[Deleted member 105166]

The basement has it's own circuit panel - the max load stated on the labelling in 40a. That's via SWA from the main house board (as it runs out of the house, around the building and back down into the basement). This feeds 4 external double sockets via 1.5mm cable.

Are the 4 external double sockets all on one circuit, or separate circuits?
What is the size of the MCB protecting the 1.5mm cable?
What type of cable is this 1.5mm?

 

[Spoon]

The basement has it's own circuit panel - the max load stated on the labelling in 40a. That's via SWA from the main house board (as it runs out of the house, around the building and back down into the basement). This feeds 4 external double sockets via 1.5mm cable.

Are you sure it's 1.5mm feeding the sockets???

 

[Deleted member 105166]

Are you sure it's 1.5mm feeding the sockets???

that'll only work in pyro.

 

[AP1984]

Are the 4 external double sockets all on one circuit, or separate circuits?
What is the size of the MCB protecting the 1.5mm cable?
What type of cable is this 1.5mm?

They are all on one ring circuit but sorry, it's actually 2.5 - twin and earth. MCB protecting it is 40amp

 

[Deleted member 105166]

They are all on one ring circuit but sorry, it's actually 2.5 - twin and earth. MCB protecting it is 40amp

For a ring final circuit in 2.5mm T/E, a 32A protective device should be fitted.

 

[Spoon]

They are all on one ring circuit but sorry, it's actually 2.5 - twin and earth. MCB protecting it is 40amp

As above mate. Hope you don't have a ring main using 2.5mm protected by a 40A breaker..

 

[MJPD29]

The basement has it's own circuit panel - the max load stated on the labelling in 40a. That's via SWA from the main house board (as it runs out of the house, around the building and back down into the basement). This feeds 4 external double sockets via 1.5mm cable.

I get what you mean now. Presumably it is 2.5 to the sockets. Double check this to be sure

 

[Kidsolo]

This feeds 4 external double sockets via 1.5mm cable.

What is this black magic that you speak of? 2.5 mm protected by a 40 amp breaker? the cable will melt before the breaker trips.
If the basement supply cable is large enough, make a mini sub board where it enters the basement and have a circuit for basement outlets and one for the garage. Run a cable to the garage. To get away with a lower cable rating and breaker size, you make it all a power circuit in the garage by putting your light fitting on a lead and plug and situate it so it plugs into a power point instead of it's own switch (you just switch it via the power point). To take it a step further you can add a breaker or isolating switch where it enters the garage.
It all relies on the size of the cable that is feeding the basement.

 

[DPG]

What is this black magic that you speak of? 2.5 mm protected by a 40 amp breaker? the cable will melt before the breaker trips.
If the basement supply cable is large enough, make a mini sub board where it enters the basement and have a circuit for basement outlets and one for the garage. Run a cable to the garage. To get away with a lower cable rating and breaker size, you make it all a power circuit in the garage by putting your light fitting on a lead and plug and situate it so it plugs into a power point instead of it's own switch (you just switch it via the power point). To take it a step further you can add a breaker or isolating switch where it enters the garage.
It all relies on the size of the cable that is feeding the basement.

An FCU feeding the light would be better than it being on a 13A plug.

 

[Deleted account]

edit: duplicate post
[automerge]1571729133[/automerge]
You may want to think again on the size of the cable for a 30M run. dependant on load that could be quite a volt drop. And total disconnection times ( loop impedance) will need checking to ensure the overcurrent device will disconnect in the required times in the event of a fault.