Garage wiring restriction

[Hermey]

I have a garage requiring power . Firstly I have a 12 way CU with spare mcbs then from there my cable run to the rear of the property is unhindered , so can use any size or type of cable i want , however this where it gets problematic . The route the cable needs to take from the rear of the house to the garage is a blue poly pipe buried in the concrete this pipe has an internal diameter of 14mm. So my question is what cable to use on this run . would i be alright with 4mm . I realise in an ideal world this would be armoured but the pipe restricts me from using that The garage is eagerly awaiting a supply ,it has a garage CU supplying one power ring with 5 sockets and on lighting circuit.that i have just installed . No heating will be required in the garage .
Distance from Main CU to rear of property 20m
Distance from rear of property to Garage CU 7m
Thank you for your time in reading this

 

[1john]

how deep is the blue poly pipe buried??

 

[GaryMo]

I wouldn't run anything other than SWA which gives you a problem.

This blue pipe, is it the type normally used for water? How deep is it buried?

Can you not dig a new trench to the required depth then you can install the correct type and size of cable?

 

[Hermey]

Im afarid i dont know the depth it was thare when i moved in ,it does go under a small wall which is another reason i dont want to dig up really.
Im also unsure what the pipe was made for could be made for water but the position its been fitted suggests it was intended for a cable as it emerges through the garage floor an is clipped up the wall to about 5 foot high.

 

[Lectrician]

A 2.5mm 2 core SWA may just fit into the pipe, but it would depend on the length of the pipe.

You should not be putting any type of cable into a BLUE duct - It is blue and identified as water. You should be using black duct, and obviously of an adequate size or greater. It should also be installed to the correct depth, and have a marker tape above.

 

[1john]

An MI cable would fit, just not sure if it would pull through the poly pipe ok.

 

[Steve]

Dig another trench. Stop fannying around trying to use that pipe. Use it for water as its intended for.

You said the route is unhindered, but then you say you've only got 14mm to play with.

Run a length of 10mm² 3 core SWA.

 

[ban-all-sheds]

so can use any size or type of cable i want

No, you cannot and you may not.

You have to use the correct size given the current it has to carry and the distance, and you have to use the correct type given where and how it is installed.

it has a garage CU supplying one power ring with 5 sockets and on lighting circuit.that i have just installed

When you applied Building Regulations approval what did you say about how you would ensure compliance with Part P?

What testing have you done on the garage circuits?

 

[Hermey]

OK ...I can run it in any cable i NEED to is what i meant. (is that better for you?) However thank you for your imput as i was going to use a very light gauge of speaker wire for this part of the run......Jesus....

 

[sparkwright]

OK ...I can run it in any cable i NEED to is what i meant. (is that better for you?) However thank you for your imput as i was going to use a very light gauge of speaker wire for this part of the run......Jesus....

Well, I don't know what's upset him.

Does the polypipe enter the house?

If not, what is between the polypipe and the house?

The idea of using a pyro/mi cable is possible. Is there a draw wire in the pipe?

Nylon draw tapes are available.

Pyro/mi is difficult for a diyer to terminate imo, so you may need help.

Is burying a new decent sized swa cable an option?

 

[Hermey]

Thank you Sparkright - Yep he obviously didnt get any last night.
The pipe comes up outside paralell with the rear wall ,there is a slight deviation as it enters the ground which i think would rule out PYRO .There is a draw wire fed through at the moment . Burying a proper SWA cable is what will happen eventually in 2-3 years when i get the that part of the garden dug up and re layed / paved when i can afford it . So it is really a semi temperory measure im looking for . I would not dream of moving houde and just leaving it with a temperory cable going through a water pipe buried at an unknown depth for somebody to dig through.
Thanks again

 

[ban-all-sheds]

OK ...I can run it in any cable i NEED to is what i meant. (is that better for you?) However thank you for your imput as i was going to use a very light gauge of speaker wire for this part of the run......Jesus....

Perhaps if you wrote what you meant, instead of what you didn't mean....

Given the rest of your post it didn't seem as though you were taking any notice of what you needed, and were focusing on what you wanted.

it has a garage CU supplying one power ring with 5 sockets and on lighting circuit.that i have just installed

When you applied Building Regulations approval what did you say about how you would ensure compliance with Part P?

What testing have you done on the garage circuits?

 

[ban-all-sheds]

Well, I don't know what's upset him.

Nothing whatsoever - I was just helping the OP by pointing out that he couldn't stick anything in there just because it was what he wanted, or because he wanted to use water pipe as conduit, or because he didn't want to use properly installed SWA.

....polypipe .... polypipe ... Is there a draw wire in the pipe?

521.6

 

[ban-all-sheds]

Thank you Sparkright - Yep he obviously didnt get any last night.

You aren't going to get on very well with looking for electrical installation advice if you're going to react like that when people give you advice that you happen not to like.

Burying a proper SWA cable is what will happen eventually in 2-3 years when i get the that part of the garden dug up and re layed / paved when i can afford it . So it is really a semi temperory measure im looking for . I would not dream of moving houde and just leaving it with a temperory cable going through a water pipe buried at an unknown depth for somebody to dig through.

Unacceptable.

You should do it right, or not at all.

1) Water pipe does not comply with the standards for cable ducts.

2) There are no exemptions in the Building Regulations for "temporary" fixed installations.

3) There are no exemptions in the Wiring Regulations for "temporary" fixed installations.

 

[sparkwright]

OK ...I can run it in any cable i NEED to is what i meant. (is that better for you?) However thank you for your imput as i was going to use a very light gauge of speaker wire for this part of the run......Jesus....

Well, I don't know what's upset him.

I actually meant, 'I don't know what's upset Hermey', followed by smiley face for comic affect.