Running electrics to summer house.

[martynh99]

Just had the garden paved and a summer house installed and now need some electrics in there. Nothing fancy, just enough for a socket to put something like a CD player, a security light (150w) and to run the christmas lights from when it's that time of the year.

I had some 25mm MDPE pipe run from the site of the summer house under the paving at a good depth and the plan was to run this to the house then tap into the back of a dual socket on the ring but with the MDPE in place I have the option to run it to the garage(integrated) where the main RCD box is.

Now the times come to run the cable into the MDPE i've started to look more carefully at how to do it properly, originally I was just going to run 2.5mm T+E through the MDPE.
The total run from summer house to garage is about 20m max

My current thinking is something along the lines of running some SWA from the main RCD , maybe this cable or would I need 2.5mm ?
Prysmian LV Armoured 6493X 3-Core Cable 1.5mm² x 25m Black | Armoured Cable | Screwfix.com

then at the summer house end something like one of these Crabtree 2-Way Fully Insulated Main Switch Consumer Unit | Domestic Consumer Units | Screwfix.com to run a mini-ring main for the xmas lights / cd player and then a seperate lighting run for the security light.

 

[telectrix]

1. what's the diameter of the pipe?
2. have you put a draw rope in it?
3. this work is notifiable, so are you using an electrician, or paying LABC £300+?
4. i'd certainly install at least 6mm SWA in the duct.
5. have you placed a "warning buried electrical cable" above the duct?

 

[martynh99]

Thanks Telectrix

1. what's the diameter of the pipe?
25mm external so about 20mm i'd say internal bore
2. have you put a draw rope in it?
Oh yes
3. this work is notifiable, so are you using an electrician, or paying LABC £300+?
Thats one thing i'd overlooked. If I ran the cable in and just left all the connections for them to do, is it likely a sparky will refuse to cert ?
4. i'd certainly install at least 6mm SWA in the duct.
will that fit in 25mm MDPE, I also have a 90degree elbow joint to use to get into the garage wall, will swa bend that much in 25mm diameter MDPE pipe ? If not could I go into a weatherproof box externally then into garage from back of that ?
5. have you placed a "warning buried electrical cable" above the duct?
Yes but thats already covered up now with the base for the paving & slabs all fixed in place. For the part P / LABC would that have to be visually checked

 

[GMES]

Thanks Telectrix

1. what's the diameter of the pipe?
25mm external so about 20mm i'd say internal bore
2. have you put a draw rope in it?
Oh yes
3. this work is notifiable, so are you using an electrician, or paying LABC £300+?
Thats one thing i'd overlooked. If I ran the cable in and just left all the connections for them to do, is it likely a sparky will refuse to cert ?
4. i'd certainly install at least 6mm SWA in the duct.
will that fit in 25mm MDPE, I also have a 90degree elbow joint to use to get into the garage wall, will swa bend that much in 25mm diameter MDPE pipe ? If not could I go into a weatherproof box externally then into garage from back of that ?
5. have you placed a "warning buried electrical cable" above the duct?
Yes but thats already covered up now with the base for the paving & slabs all fixed in place. For the part P / LABC would that have to be visually checked

That is going to be tighter than some of the members on here.

 

[telectrix]

thanks telectrix

1. What's the diameter of the pipe?
25mm external so about 20mm i'd say internal bore
2. Have you put a draw rope in it?
Oh yes
3. This work is notifiable, so are you using an electrician, or paying labc £300+?
Thats one thing i'd overlooked. If i ran the cable in and just left all the connections for them to do, is it likely a sparky will refuse to cert ? most sparks would be ok with that
4. I'd certainly install at least 6mm swa in the duct.
Will that fit in 25mm mdpe, i also have a 90degree elbow joint to use to get into the garage wall, will swa bend that much in 25mm diameter mdpe pipe ? If not could i go into a weatherproof box externally then into garage from back of that ? yes to the box. Looks like you're stuck with 2.5mm, and that will be tight.
5. Have you placed a "warning buried electrical cable" above the duct?
Yes but thats already covered up now with the base for the paving & slabs all fixed in place. For the part p / labc would that have to be visually checked. should be ok

my comments in red.

 

[martynh99]

6mm SWA, isn't that upto 62Amps ?

If my memory is correct (30 years since school), Amps = Watts / Volts so
150w security light is 0.625A
CD Player has a 3A fuse in plug so thats 3.625A so far,
3 lots of xmas lights, again 3A fuse in each so 9A
total 12.625A assuming all used at same time and upto the fuse limit in each plug.

1.5mm 6942X 2 core SWA Steel Armoured Cable this is 1.5mm SWA and it says it's good upto 27A

 

[telectrix]

1.5mm 16A
2.5mm 27A
6.0mm 47A.

OK, for what you want 2.5mm will do, but think if you want a heater on a cool evening, 9A on top of what you've planned. so i'd go with 2.5mm. you'll never pull 6mm in there. advise to install 3 core, then get electrician to test it and then connect up.

 

[martynh99]

1.5mm 16A
2.5mm 27A
6.0mm 47A.

OK, for what you want 2.5mm will do, but think if you want a heater on a cool evening, 9A on top of what you've planned. so i'd go with 2.5mm. you'll never pull 6mm in there. advise to install 3 core, then get electrician to test it and then connect up.

Great, thanks for the advice - missed that the link I posted was only 2-core