Flexible inground electrical conduit

Forums › Home Workshop DIY › Flexible inground electrical conduit

1 | 2 | 3

11294 posts

Uber Geek
+1 received by user: 10018

Trusted

Lifetime subscriber

#2777700 13-Sep-2021 16:46

elpenguino:
If it never appears above ground, then just all the other negative points are stacked against its' use.

If it's being buried by hand then at some point in the future some of it will reappear above ground. Even with a digger to help you have to bury it down some way to prevent bits of it resurfacing at some point.

sparkz25

750 posts

Ultimate Geek
+1 received by user: 284
Inactive user

#2777846 13-Sep-2021 21:42

coffeebaron: I would suggest the alkathene pipe too. Pulling cable through flexi can be differcult.

I would go down this path! it's cheap easy to work with and you can get it in 50m coils, you don't even have to put a draw wire in, a plastic bac with a string tied to it and a vac on the other end works a treat!

The longest run I have done with a bag and string was 150-160m, and it worked a treat.

Jase2985

13735 posts

Uber Geek
+1 received by user: 6214

ID Verified

Lifetime subscriber

#2777850 13-Sep-2021 22:13

https://store.nzfarmsource.co.nz/store/water/pipe/alkathene

50mm x 25m going upwards in length

kiwis

837 posts

Ultimate Geek
+1 received by user: 12

#2777864 13-Sep-2021 22:56

I think this would be the answer... I'd need 5-8m max not 50.

I'm looking around on FB marketplace & trademe for some offcuts or secondhand stuff

neb

11294 posts

Uber Geek
+1 received by user: 10018

Trusted

Lifetime subscriber

#3315299 2-Dec-2024 20:19

I'm now running into something similar, I've got come conduit carrying +/-12VDC voltages that I need to route over a path that's pretty much impossible for rigid conduit, around deck piles, across a rockery, along the side of a curving path, around trees and tree roots... I normally use rigid conduit everywhere but in this case I'll have to make an exception. What I was thinking of doing is burying 20mm flex conduit, possibly run inside some 32mm flex conduit for extra protection across a patch of lawn where it's possible someone may dig in the future. When I'm burying conduit I always bury multiple cut-up lengths of fossilised garden hose over the top, both to provide a flexible shock absorber and so if in the future anyone sticks a spade down there they'll hit the garden hose rather than the conduit.

I've had a look for alkathene pipe but you need to buy it in (expensive) rolls, and I'm also not certain it's flexible enough to run around the things I need to run around. The other option is to use heavy duty (orange) rather than medium duty (grey) flex conduit, but looking it up it just adds another 0.15mm wall thickness which I'm not sure makes that much difference.

Does anyone have any other suggestions?

Danite

43 posts

Geek
+1 received by user: 18

#3315384 3-Dec-2024 00:17

Depending on how much you are willing to spend, could just install a neutral screen cable. More fiddly to fit off at the other end but would be flexible, can be buried direct and is generally safe as you make the screen the 0V. Sold by the meter so can just get what you need, will need access to a wholesaler though.

Would be cheaper than 25mm flexi inside 32mm flexi + cable I would expect.

Geekzone support

Support Geekzone with one-off or recurring donations Donate via PressPatron.

SomeoneSomewhere

1882 posts

Uber Geek
+1 received by user: 1086

Lifetime subscriber

#3315387 3-Dec-2024 00:32

Yeah, if it's 12V you have no legal requirements for mechanical protection; it's entirely a longevity/risk question.

Steel Wire Armour cable (SWA) is also an option. You don't need to earth the armour at either end if it's ELV so you can just cut the armour off and use standard cable glands.

neb

11294 posts

Uber Geek
+1 received by user: 10018

Trusted

Lifetime subscriber

#3315392 3-Dec-2024 01:42

The +/-12V isn't pure DC, there's a thicker DC cable and second one with multiple twisted pairs for RS485 so I will need some sort of conduit or similar to run it in. The reason for the overengineering was that I really don't ever want to dig it up again in the future if there's a problem, particularly since it'll likely get all manner of semi-permanent stuff added over the top of where it's meant to run.

Danite

43 posts

Geek
+1 received by user: 18

#3315396 3-Dec-2024 06:58

Novaflow or Novacoil type product? 15m for $130ish 65mm at Bunnings.

How far are you actually looking to go?

neb

11294 posts

Uber Geek
+1 received by user: 10018

Trusted

Lifetime subscriber

#3315482 3-Dec-2024 13:54

Hmm, interesting point, although I'd get their house-brand stuff for $35 rather than pay the Marley tax. It's only providing protection against heavy stuff run over the top and spade damage so doesn't have to be a solid armoured sheath. The portion that runs underground is about 5-6m (depending on what sort of obstacle the rockery is), the rest is under the deck so it won't need anything more than basic conduit.

It's an annoying length of run because no-one wants to sell you less than half a km of the stuff.

elpenguino

3577 posts

Uber Geek
+1 received by user: 2939

#3315496 3-Dec-2024 14:49

neb:

Hmm, interesting point, although I'd get their house-brand stuff for $35 <SNIP>

I recently used that exact product (to run water through , bizarrely) and it is not such a heavy material, which is how 6 odd metres of pipe concertinas into a thing the size of a large book.

You might want to evaluate its heft before deciding it is adequate.

Most of the posters in this thread are just like chimpanzees on MDMA, full of feelings of bonhomie, joy, and optimism. Fred99 8/4/21

Geekzone

Want to support Geekzone and browse the site without the ads? Subscribe to Geekzone now (monthly, annual and lifetime options).

neb

11294 posts

Uber Geek
+1 received by user: 10018

Trusted

Lifetime subscriber

#3315500 3-Dec-2024 14:59

Sure, it's cheap junk that I'd never actually use in anger, but its only purpose here is to act as a sacrificial layer between the environment and the conduit/cable. It doesn't matter if it gets crushed or punctured at some point, although having it fill up with water is a concern.

SomeoneSomewhere

1882 posts

Uber Geek
+1 received by user: 1086

Lifetime subscriber

#3315542 3-Dec-2024 16:55

Conduit underground is a wet area, no if or buts. Condensation will fill it if leakage doesn't

Scott3

4177 posts

Uber Geek
+1 received by user: 2990

Trusted

Lifetime subscriber

#3315557 3-Dec-2024 17:27

A heat gun can be had for $30

https://www.mitre10.co.nz/shop/number-8-heat-gun-2000w-orange/p/353393

I would run with that and a few lengths of electrical conduit:

https://tradedepot.co.nz/electrical-conduit-40mm-x-4m-white/?gad_source=1&gclid=CjwKCAiA0rW6BhAcEiwAQH28IjzhB2NIGDs8kC2hocEFEA-_OR00UpDS8hrmJprZ2Z_WQ9KqECHGexoCUscQAvD_BwE

You are ment to use a spring inside conduit for bending, but as long as your radius isn't too tight you can make do without.

neb

11294 posts

Uber Geek
+1 received by user: 10018

Trusted

Lifetime subscriber

#3315565 3-Dec-2024 17:44

neb:
Sure, it's cheap junk that I'd never actually use in anger, but its only purpose here is to act as a sacrificial layer between the environment and the conduit/cable. It doesn't matter if it gets crushed or punctured at some point, although having it fill up with water is a concern.

Just had a poke around the Green Church, they have grey-water flex pipe that looks like it'll work in this role too. Cheap and flimsy but it's PP so it'll last forever and will be fine as a sacrificial layer.

1 | 2 | 3