16MM SWA CONDUIT OR BARE

[Lazurus]

So the workshop is coming along I dug the trench for the power feed from main CB in bungalow and the sparky came and dropped the SWA in, he laid it straight in the trench for me to back fill, now I had purchased suitable twin wall conduit but sparks said as it was only under a patio and not a drive way or near other services conduit not required. Do you think it is worth re laying in the conduit (trench still open) or just leave as is?

 

[Agroshield]

Warning tape over the SWA, lay the conduit alongside with a rope through it in case you need data or water in the workshop.

 

[James1979]

Warning tape over the SWA, lay the conduit alongside with a rope through it in case you need data or water in the workshop.

Exactly what I did. And i ended up pulling data through it

 

[Lazurus]

Warning tape over the SWA, lay the conduit alongside with a rope through it in case you need data or water in the workshop.

Now that is a great idea, yes I have the tape and space to leave a spare conduit with pull cord - brilliant thank you. Obvious when you think about it.....

 

[Anguz]

or what i did... a bit of ducting... got loads going thru mine now... air, power, camera feeds and data

 

[Justme]

When you pull new cable through also pull a new rope at same time.

I put an extra long rope in mine coiled at each end & fixed so it cant pull out.

 

[MetalMonkey]

or what i did... a bit of ducting... got loads going thru mine now... air, power, camera feeds and data

Just a word of caution on this - data/low voltage signals should be kept separate from power.
I run two conduits, you can use the same trench, just try and keep them separated.

 

[Anguz]

Just a word of caution on this - data/low voltage signals should be kept separate from power.
I run two conduits, you can use the same trench, just try and keep them separated.

The word is should..... never had a problem short distances... never had problems at work and the runs there are much further

 

[MetalMonkey]

The word is should..... never had a problem short distances... never had problems at work and the runs there are much further

Generally it will still work, but obviously the more induced interference, the more potential error correction and the less potential speed.
There is also a safety issue if cables are damaged and mains bridges on to the data cables, so always best to keep them separated if you can (not always possible).

Another issue that isn't mentioned much is if you get a high voltage spike from something like a lightning strike on a power line - this can toast network interfaces.
I had one that did £89,000 of damage and took out a load of network switches, and it wasn't even a direct hit!

 

[Anguz]

i have seen a lightning strike blow twin and earth from plaster, rip a db off the wall, and wreck most electronic devices in the building
nothing will protect, unless you are talking of separating to the next county

 

[Edward Teach]

Doesn't cable buried in the ground have a lower power rating than cable in a ducting
Though 16mm2 cable is quite large.

 

[brightspark]

i have seen a lightning strike blow twin and earth from plaster, rip a db off the wall, and wreck most electronic devices in the building
nothing will protect, unless you are talking of separating to the next county

i used to do callouts and saw a fair few one the gable end of house got struck and blew a 5 foot hole through the brickwork and dropped the lot through the bedroom ceiling on to the kiddies cotfortunately they took it downstairs 5 mins earlier as u say the whole of the electrics were trashed .the kettle in the kitchen was blown across the room and an imprint of the plug was in the plaster wall . if you fancy shelling out fit a lightening conductor to earth it out

 

[Onoff]

I'd lay in ducting everytime. So much easier to upgrade / replace. From my garage to electric gate I scored a length of DNO duct for a tenner off eBay.

Bloody hilarious getting that from Esher to Sevenoaks on the Golf roof rack! Talk about put up a fight.

Wasn't so happy digging 13m long, 700mm deep by 6" wide by hand!

In it I've a 2.5mm SWA then a Cat-5 and random screened 4 core I had lying around both in their own 20mm flexy conduits. The smaller cables are long enough to go back to the house for comms / video door bell.

Not too worried about the cables together. Something in the regs about 100mm separation I recall but that also if separated by an insulated barrier/duct...which I have. I took it to mean they can be closer.

 

[Lazurus]

I had another look this morning, the swa is currently under a few inches of water in the trench, I will leave that as is but will lay the ducting in the trench also as hopefully then I am future proof after the patio is laid, thanks all for the info and ideas. Appreciated

 

[bigegg]

I'd lay in ducting everytime. So much easier to upgrade / replace. From my garage to electric gate I scored a length of DNO duct for a tenner off eBay.

Bloody hilarious getting that from Esher to Sevenoaks on the Golf roof rack! Talk about put up a fight.

Wasn't so happy digging 13m long, 700mm deep by 6" wide by hand!

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In it I've a 2.5mm SWA then a Cat-5 and random screened 4 core I had lying around both in their own 20mm flexy conduits. The smaller cables are long enough to go back to the house for comms / video door bell.

Not too worried about the cables together. Something in the regs about 100mm separation I recall but that also if separated by an insulated barrier/duct...which I have. I took it to mean they can be closer.

The thing which worries me about data+power cables being together is if rats (or whatever) decide to chew the insulation, then you could potentially have mains voltage on the data lines.

 

[brightspark]

The thing which worries me about data+power cables being together is if rats (or whatever) decide to chew the insulation, then you could potentially have mains voltage on the data lines.

thats why you seal the ends up with foam rats wont eat or chew the armoured cables they will chew flat twin and earth pvc cables though

 

[Anguz]

My data cables are poked thru a bit of blue mdpa waterpipe thats inside the duct

 

[bigegg]

thats why you seal the ends up with foam

I've had rats chew through foam to gain access to "rat runs". Yes. I know. Add steel mesh. They'll pull that out as well, given time.
Plus: contaminated ground water (petrol? Diesel?) in the (buried) conduit could/will eventually damage the insulation.
Its probably unlikely, but it's why *I* would use separate conduits.

 

[bigegg]

My data cables are poked thru a bit of blue mdpa waterpipe thats inside the duct

That's what I used, as well.

 

[brightspark]

broken glass in cement sort rats out