Can this be done..... ?

[sythai]

Hi Chaps...

Running sub main to shed - SWA.

Can the plumbers put his alkerthene (dodgy spelling there I know:cheesy pipe in there also ?

Any reg on this, spacing required etc....?

Thank you,

Sy

 

[Marie-Claire]

Hi Marie-Claire , if my memory had been on the ball i think it would have been more to do with segregation of services rather than temp dissipation ,
Having said that , do be carefully if you ever do speck a buried cable as you will have to take account of it and down rate it's load carrying ability more than a suspended one .

im thinking off the top of my head but im pretty sure ambient temp has to be taken into consideration in most cases of installing cables and i dont know what the pipe is that the swa is next to and if there is warm/hot water passing through it

 

[JD6400]

Very good point , but if it were hot water i would hope it had been well lagged unless they have there own tame volcano :devilish:

 

[Spudnik]

50mm flexible duct is what i bury for my cables.

 

[JD6400]

We do a fair bit of moling/thrust boring and usually pull anything from this up to 6" in behind the expanders , does the job a treat !

 

[Engineer54]

Actually there are thermal derating factors applied to LV multi core cables buried over 600mm either direct buried, or in ducts!!

Also on the bigger projects, where pressurised water mains are buried, that require ''trust blocks'' at changes of direction, ...then it is not permitted to run electrical services in the same trench or near that trench come to that!! . In fact it would be very foolish to do so, if anyone here has seen what a burst 10'' pipe at or on a trust block can do!!!

 

[NMc]

For buried cables and those buried in ducts etc, Regulation 433.1.4 requires a factor of 0.9 to be applied to the current-carrying capacity (Iz) of the lowest rated conductor in the circuit protected :

In ≤ 0.9 Iz