Burying BT dropwire or CW1128 cable

[nothanks]

I need to run a signal cable to a gate, the run is about 30m underground and 30m hung on a stock fence. Armoured signal cable is very expensive so I'm tempted to use either exterior phone cable or Dropwire (both have polyethylene outer jackets and are to BT specs) and direct-bury the underground bit tied to a 2.5mm2 2-core SWA cable, rather than bothering with trunking. The trench is in stable clay, there aren't any stones and the only roots are small fibrous ones. What does the team think?

[Harry Bloomfield Esq]

[e-mail] wrote on 29/01/2022 :

What sort of signal and how important is the signal?

[nothanks]

Hmm, after a bit more searching I'm surprised to find that external Cat5 cable can be direct-buried and is a cheaper option than even used BT Dropwire, so that's probably the answer.

[Andrew]

Underground BT incoming cable is armour protected and thus has a double PVC shell. I'm not sure if the above-ground BT drop wire is suitable for burying.

[Andrew Gabriel]

I buried external Cat5e and it's been fine for 10 years so far. I think it just had an extra tough jacket over it. It comes on 100m reels so you might as well lay two runs, even if you only need one.

Cheers Andrew

[Mike Clarke]

External CAT6 is also filled with silicone grease - I'd expect external CAT5E to be also. Provides additional moisture protection but makes terminating it a really messy job.

If you shop around you can also get 50m reels.

[The Natural Philosopher]

What sort of signal? Ethernet might struggle with BT cable over that distance. There will be a lot of capacitance to ground on the underground section that will limit HF performance.

OTOH if its DC signalling it should be fine.

[Tricky Dicky]

If you are running SWA to the gate why not consider using Ultra EV cable from Doncaster cables which is SWA that includes data cables within the SWA insulation. It is primarily for smart EV chargers that need data transmission but would certainly do your situation in one cable.

Richard

[nothanks]

Thanks for the suggestion; I hadn't heard of that. The idea's interesting but unfortunately the cable only has one pair of data wires, is 3 core 4/6mm2, and is £5+/m! I need (want) more than one pair, only need 2 core (because of the distance I won't be exporting the earth) and

2.5mm2. It looks like external Cat 5 strapped to 2.5mm2 SWA, is the way to go (unless there are other power+data cables that I haven't found).

[Tricky Dicky]

They have two types one just with a data pair but the other has Cat5E

Richard

[Robert]

MDPE water pipe would provide a lot of protection for a normal CAT 5e data cable (or two) is cheap and designed for burying.

[Brian Gaff (Sofa]

What will it be actually carrying though? Brian

[Brian Gaff (Sofa]

How is he powering the gate? If its mains then Id have thought just one extra wire in that conduit would be ok. Brian

[nothanks]

Thanks again, but that's £7.40/m.

2-core, 2.5 SWA is £1.40/m, external Cat5 for direct burying is <£1/m.

[nothanks]

True, and I happen to have about 50m of MDPE in the shed, but the price difference between regular Cat5 and direct-burial Cat5 doesn't seem to be very big so isn't worth the hassle

[Chris Green]

I've buried two lengths of standard Cat5E in MDPE pipe using my mole plough, worked a treat. Using the mole plough you need something fairly robust to bury.

[Andrew]

But there is a minimum order length that may be more than required (according to various supplier websites)

[Andy Burns]

toolstation sell it cut by the metre. But the O/P only wanted 2 core

[nothanks]

Cough £6 cough 29p cough per metre - I need to go and lie down ;-) More seriously, 62 metres of 2.5mm2 6942X is £69.44 and 100m of direct-buriable Cat5e is either £39.90 (copper) or £24.20 (CCA)

[nothanks]

Oops, that should be 83.33 rather than 69.44 ... the dreaded VAT