Outdoor power cable routing...

[House_Hunter]

So planning on running a cable from the house down the garden to supply power for some garden lights.

I am planning to route the cable through some black MDPE pipe (highlighted to state electrical wires inside).

My question is:

Should I drill holes in the pipe to let any fluid get out?

I don't like the idea of the cable sitting in water if some water got into the pipe conduit.

What are peoples thoughts?

Cheers!

 

[malcolmsanford]

What size pipe and what size and type of cable do you intend running.

Also you know that you have to notify this to the LABC if your not part of a self certification scheme.

 

[House_Hunter]

Many thanks....fully aware of certification requirements. Which are all ok.

Thinking of using 32mm MDPE pipe running 3-core 2.5mm inside; either NYY-J cable or SWA depending on whtehr I am able to dig a trench or need to surface route.

 

[Coffeemad]

Drilling holes in the bottom of the pipe will allow water out, but it will also allow water in as the water table rises. I would also suggest that you bury the cable/pipe at least 300 - 450mm deep (beyond spade and fork depth) as an added safety measure. As to the type of cable for this job (and in my humble opinion), a 3 core SWA everytime.

 

[malcolmsanford]

HYY-J is pretty expensive stuff last time I used it which was for mainly industrial use. But you can bury that as well so no problems.

 

[House_Hunter]

Ok....was wondering about water table rises as well......

Any recommendations for pipe entry/exit arrangements to stop water ingress then if I don't dill water exit holes?

FYI:
NYY-J Cable: NYY - Protected Cables

 

[spud1]

I would recommend bury to a depth of 600mm under flower bed or lawn. But agree with rest of coffeemads comments.

 

[spud1]

You wont stop water getting in. It always finds a way

 

[malcolmsanford]

Ok....was wondering about water table rises as well......

Any recommendations for pipe entry/exit arrangements to stop water ingress then if I don't dill water exit holes?

FYI:
NYY-J Cable: NYY - Protected Cables

There you go cheaper than SWA ..............live an learn

 

[House_Hunter]

I posted the link to NYY-J in reference to your post about HYY - which I haven't come across before....

Agree...will be almost impossible to stop water getting in....which then leads me back to the original question - should you have drainage holes?

What have other people done? Do you care about your SWA potentially sitting in water?

 

[malcolmsanford]

No you can bury SWA direct in the ground without feeding through a pipe. That's why the majority of time it is most sparks first choice of weapon.

I have seen, if you want to do it. extend the pipe about a foot above ground level each end of the run, Fix it to the wall with a clip, SWA clip is good and dollop some silicone in either end. It,s not perfect and over time it can effect the PVC of the cable but not sure if NYY-J will be that affected. Most time when you use pipe for drawing in cable it normally terminates inside a man hole or a chamber.

 

[lynpgc]

do it to iee regs

 

[House_Hunter]

Fair do's.....cheers for the advice.

How easy is swa to terminate in say a light fitting though? Heard it can be a pain....if not impossible!

Would seem a little messy to have a swa run to a JB, then NYY-J from the JB to the light? Surely must be a neater solution?

 

[Coffeemad]

Don't forget that you will want to then run the SWA on to the next light point, assuming you are having more than one light. If you do, don't forget to fit the banjo's inside the adaptable box to the SWA's and connect the two with 4mm earthwire

 

[House_Hunter]

I was going to use 3-core instead of relying on the armour for earthing.....would you still recommend earthing the armour as well though (via banjo's)?