Alarm cable buried in concrete

[Jupiter01]

hi,

I have a texecom system which will have a pir installed in my outdoor tool shed. I will need to bury some of this alarm cable into concrete as it will be underground. Can I stick it in a conduit and concrete over?

Any other tips will be gratefully received. Thanks in advance

 

[Handymanjo]

Conduit will be fine
If possible try to keep access to both ends that way you can add or replace cable if required.
25mm is better ,if you require other cables later

 

[rsgaz]

bury some of this alarm cable

Ordinary PVC alarm cable is not suitable for outdoor or underground use. It will stop working eventually.

You need some "duct grade" cable, which usually just means a black polyethylene jacket instead of white PVC.

If you want flexible conduit rather than galvanised steel, you want "twin wall ducting". Smallest size you'll probably find is 32mm/40mm
https://www.draindepot.co.uk/40mm-x-50m-black-twinwall-electric-cable-duct.html

 

[sparkymarka]

In about 30 years .....

 

[Jupiter01]

30 years before it stops working?

 

[rsgaz]

In about 30 years

I have seen grey PVC cable laid in a gutter which had lasted 15 years before developing intermittent faults when it rained, I already thought that was amazing to last that long! If you've seen 30 year cable, then wow!

BUT, on the other hand, I have seen white CW1308 cable clipped on some brickwork where the jacket had disintegrated and turned into individual short tubes that you could slide up and and down the pairs! The building was only 3 years old, but I don't know when this cable was added, so can't say the actual age, just <3.

Jupiter, as you are putting in ducting, it will be easy to replace when it fails, so it's up to you really, I was just advising the 'proper' way of doing it.

 

[sparkymarka]

It's in ducting NOT in sunlight which will perish the outer sheeve and then onto the inner cores ! The only advantage to duct grade will be if multiple cables are going down that duct ( cable burn)