Burying ethernet cable with armoured mains to shed

Gas & water pipes are buried, not exposed to uv. My experience with polythene gerenhouses is that they're a gonner in 4 years. Maybe I'll use the pe stuff.

NT

You can always suck a ping-pong ball or similar through with some fine cotton attached to the ball even if you forget the draw string.

Fair point. Dropwire No.10 is though and flaps about in the wind. I think our dropwire has been replaced once but so long ago I can't remember exactly when but probably > 15 years ago.

"Polythene" for polytunnels etc is clear/translucent, that has a bearing on the UV resistance. I did a bit of a google to check the MDPE for gas water pipes and on cable jacket types. PE as a cable jacket type scored better than PVC on several different pages.

thanks.

PS I wonder if that translates to PE underlay being ok too.

NT

I sit corrected, if not totaly convinced by the quoted specifications.

That might work initially, but you should always assume ducts will eventually fill with water as condensate collects slowly, even if it doesn't have any leaks in it.

It's not just that - underground cables do break. Having a spare (providing it didn't break first) can be useful in such circumstances.

Indoors, back in 2000, I ran 2 to each room, 3 to the living room> Wasn't enough - they are all in use, with a couple of extra switches too.

Some US states have a good rule for positioning sockets. Something along the lines that an appliance with a 6' lead must be able to be positioned anywhere around the wall of the room and plugged in without the cable crossing a doorway.

You should assume underground ducts will fill with water over time. Condensation has no way out.

They clear fibre ducts (as in telcoms distribution) by blowing through with compressed air and a soft plug. AIUI you don't want to be hit by the plug when it comes out...

Sucking limits you to 15 psi max. Blowing can use much higher pressures.

Wiki has wrong depth?

wiki says How deep?

An underground cable will normally be laid in a trench, and then the trench back filled to cover it.

The cable needs to be buried deep enough that it is unlikely to be disturbe d accidentally in future. There are no hard and fast rules here since circu mstances will dictate an appropriate depth. In areas unlikely to be dug ove r or disturbed such as under a path or a lawn, then shallower burial is acc eptable - possibly a spade's blade depth or around 12".

but i believe regs are now 50cm arent they?

Which regs though?

BS7671 (aka "the wiring regs") seems to be silent on the matter - they specify a 50mm separation between mains and communications cables, but not a minimum burial depth. Can't see anything in the on site guide either.

The specs like BS5467 (for armoured thermosetting cables) only mention burial once and then only in the context of it being suitable for burial.

Can't see anything in the electrician's guide to the building regs either.

old regs, section 708, Reg 708.521.1.1: Underground cables shall be buried at a depth of at least 0.6m ......

I'm buying my copy of the new regs on Friday

ah ok, yup that section is still there in the 18th edition, but that section lists specific requirements for Caravan and Camping parks.

Also the wording: "An underground distribution circuit shall, unless provided with additional mechanical protection, be buried at sufficient depth to avoid being damaged, e.g. by tent pegs or ground anchors or by movement of vehicles."

There is then a note that says that 0.6m is generally considered adequate to meet the requirement but also goes on to say that the cable could be installed outside of the area where pegs etc will be used.

So even in the context of a camp site that is still only a recommendation that depends on actual circumstances, and also the amount of mechanical protection the cable has.

Oh well that will give you something to read over the weekend ;-)

Duct colour, depth, etc all seems a bit woolly no matter the location. You might find Vol:1 on this page interesting: