Power and lighting to garden shed

[jerseymick]

Hi. I would like to supply power and lighting to my new garden shed from my bungalow which is approximately 4 mtrs, away. I intend to have a small fluorescent light and two double 13amp sockets. The shed will also house an under counter freezer and a tumble dryer.

I have discovered an old 2.5mm twin and earth cable running through my loft from the RCD consumer unit in the kitchen , and exiting under the eaves of the bungalow. (possibly supply to old demolished garage) , which incidentaly isn't live !

There is spare capacity in the consumer unit so was thinking of running a new 4mm twin and earth along the same route an exiting under the eaves into a weather proof junction box. From this point i would run a 6mm SWA cable along a catenary wire into the shed , connecting to a garage/shed consumer unit , ( maybe a screwfix BG 5 module 3 way unit ).

From this unit i would run 2.5mm twin and earth to light switch , light and sockets.

My intention is to do all the donkey work but let a qualified electrician do all the connecting up , as i have been quoted between £260 - £325 for supply and fix.

Am i correct with the cable choices and unit choices. All advice appreciated.

Cheers. Mike.

 

[Octopus]

My intention is to do all the donkey work but let a qualified electrician do all the connecting up , as i have been quoted between £260 - £325 for supply and fix.

Sounds more than reasonable to me.

And good luck getting a spark to agree to sign off your work - I wouldn't and never do........

 

[HandySparks]

First find your qualified electrician. Then agree an installation design and the tasks that he will let you do and still 'sign off' the work. If you do it any other way, you stand a fair chance of not finding anyone to co-operate.

 

[buzzlightyear]

is this cost cutters Corner or what!

 

[MJPD29]

That sounds like a good price to do it I can't see anything wrong with it. I also agree with murdoch, id be very reluctant to put my name to another electricians, and definitely not a DIYers

 

[Lip.82]

First find your qualified electrician. Then agree an installation design and the tasks that he will let you do and still 'sign off' the work. If you do it any other way, you stand a fair chance of not finding anyone to co-operate.

Hi I've just been reading through the OP and the cable sizes and the running a 2.5mm to the light switch doesn't seem right to me. Am I right in thinking that? I'm still learning and gaining experience in the trade and just wanting to know if you could put my mind to rest on this one please.

 

[HandySparks]

Hi I've just been reading through the OP and the cable sizes and the running a 2.5mm to the light switch doesn't seem right to me. Am I right in thinking that? I'm still learning and gaining experience in the trade and just wanting to know if you could put my mind to rest on this one please.

In this case, 2.5mm² cable is unlikely to be a sensible choice for lighting.

 

[Spoon]

Hi, welcome to the forum.

There is spare capacity in the consumer unit so was thinking of running a new 4mm twin and earth along the same route an exiting under the eaves into a weather proof junction box

So you are adding a new circuit. What size breaker are you going to use?

From this point i would run a 6mm SWA cable along a catenary wire into the shed

Why SWA? and why 6mm

 

[Spoon]

Also, as this falls under Part P, will you be notifying the relevant authorities? This will, of course, cost money...

 

[DJ Ovengloves]

Is the op on holiday (with all the sparkies)?

 

[Lip.82]

In this case, 2.5mm² cable is unlikely to be a sensible choice for lighting.

I don't understand why he would run a 4mm T&E then a 6mm SWA. Would I be wrong in thinking that a 2.5mm swa from the cu to the shed would be acceptable?

 

[Spoon]

I don't understand why he would run a 4mm T&E then a 6mm SWA. Would I be wrong in thinking that a 2.5mm swa from the cu to the shed would be acceptable?

It's hard to say what is good for the OP if he doesn't come back to us to give us more info.
In #8 post, I ask what size breaker he is wiring this to. Of course this will determine the min size of the cable.. (along with a few other factors). Still waiting for the OP to come back on this.
Again, in #8 post, why SWA?

 

[Lip.82]

It's hard to say what is good for the OP if he doesn't come back to us to give us more info.
In #8 post, I ask what size breaker he is wiring this to. Of course this will determine the min size of the cable.. (along with a few other factors). Still waiting for the OP to come back on this.
Again, in #8 post, why SWA?

I would use SWA because it's going from the house to the shed. As you know yourself SWA offers mechanical protection so if it's getting buried or clipped from the house to the shed then I would of thought it's the best cable to use. For what OP said he's putting in the shed I was thinking 2.5mm SWA on a 20A mcb. Then in the shed have sockets on rcbo or if the cable is on an rcd in the main board then no need for rcbo in the shed. Like I said I'm still gaining experience and like reading the posts on here and asking questions,

 

[Octopus]

Like I said I'm still gaining experience and like reading the posts on here and asking questions,

The OP appears to be a DIY chancer.

If you are learning the trade with a view to earning a living, then giving away step by step info to Joe Public on the web won't help your income

 

[Lip.82]

The OP appears to be a DIY chancer.

If you are learning the trade with a view to earning a living, then giving away step by step info to Joe Public on the web won't help your income

Fair point. I was just trying to find out if how I thought it should be done was right.

 

[I2C]

In my opinion, let the qualified electrician deal with everything for the following reasons:
- Cable calculations & permissible voltage drop - it must be calculated to identify the correctly-sized conductor.
- Discrimination - There should be adequate discrimination between the protective devices at the main incoming CU and the shed DB.
- Inspection & testing - the electrician that 'signs-off' the work must be able to see the entire circuit in order to properly check the condition and conformity of the installation.

 

[Spoon]

@Steve kirkman : Ta four da bad spelin Ratin on poast 9.