What kind of conduit do I need for buried armoured cable?

[d000hg]

We're in the midst of trenches in our garden and driveway for water and power. The groundworks company are coming at short notice for a water installation so our electrician hasn't specified the armoured cable yet and requests we bury a conduit. We're going to drop it in or get the groundworks guys to do so at required depths but I'd like to check your thoughts on suitable conduit type not to get crushed, etc.

We don't expect to lay more cables, so would it be as good just to over spec on cable?

 

[Tigercubrider]

Can't your electrician send you a hyperlink?
It would be daft to take advice off the internet for the electrician to refuse to use it

 

[chivers67]

What's the cable for? Supply to the house ? Supply to Lights ?

 

[JohnW2]

Can't your electrician send you a hyperlink?

A hyperlink to what?

It would be daft to take advice off the internet for the electrician to refuse to use it

It would, but given that there is no requirement for buried SWA to be in any sort of conduit or ducting, I can't see why the electrician would 'refuse to use' anything that he could pull the cable through

Kind Regards, John

 

[d000hg]

Can't your electrician send you a hyperlink?

in the post you mean? Is that a product name I should look up?

 

[d000hg]

What's the cable for? Supply to the house ? Supply to Lights ?

Supply from the consumer unit for external stuff... Lighting, security cameras, maybe one day a powered gate, perhaps an external socket.
So lowish power stuff but possibly a fair amount.

No electric car charging points!

 

[d000hg]

A hyperlink to what?
It would, but given that there is no requirement for buried SWA to be in any sort of conduit or ducting, I can't see why the electrician would 'refuse to use' anything that he could pull the cable through

Kind Regards, John

Indeed. I was actually wondering if a conduit is used at 450mm, does cable even need to be armoured? I think we'd go that way just to be safe

 

[JohnW2]

Indeed. I was actually wondering if a conduit is used at 450mm, does cable even need to be armoured? I think we'd go that way just to be safe

If one didn't use armoured cable, the conduit/ducting would have to be man enough to give adequate 'mechanical protection' to whatever cable was used. In practice, it would probably be daft not to use armoured cable - and, in terms of the big picture, the marginal cost (over non-armoured) would probably not be much of an issue.

Whilst the trench is open, it might be worth considering putting in a second duct, for use for data/telephone/signal/whatever cables should they ever be needed.

Kind Regards, John

 

[Tigercubrider]

A hyperlink is a link with a web address for a product
He might well refuse if the regs aren'tfollowed such as warning tape or depth

 

[JohnW2]

A hyperlink is a link with a web address for a product

A hyperlink is a 'clickable' link between two things. Many of the documents I write contain hyperlinks to things within the document (or associated documents) - nothing to do with any web addresses or products

He might well refuse if the regs aren't followed such as warning tape or depth

True, but the OP wasn't asking about that (and the depth appears to have already been specfied by the electrician).

Kind Regards, John

 

[sparkwright]

Your electrician should be telling you what size ducting to put in.

You mentioned gate wiring - this may well need it's own separate ducting.

Your electrician has done you no favours by leaving it all to you.

It's always best to run the cables in the ducting before the trench is filled in - you just don't know what problems could occur.

Some ducting already have a draw string inside, so this is perhaps what you need. This is usually something like 50mm diameter.

But since no one really knows what cables are going in, I can only suggest to use the largest ducting, and several ductings if in doubt, and also to give your electrician a massive slap for putting you in this situation.

 

[Taylortwocities]

@d000hg this sort of thing.
https://www.tlc-direct.co.uk/Products/FXKVR50.html

Size will depend on how large the SWA needds to be.

 

[d000hg]

This isn't part of the work the electrician is booked into do, and we aren't necessarily going to connect these cables up initially. But while we are digging everything up for water installation we figured we'd future proof and lay a cable down the drive.
He didn't want to commit what size cable we should bury when the requirements aren't finalized, and requested we install conduits instead so we're more flexible when the time comes.
The groundworks company is happy to lay what we want at the triggered depths, do the trenching properly.

I just want to make sure I get conduit that won't collapse when we drive over it. Any suggestions on how to choose, there's loads of different products out there?

 

[d000hg]

@d000hg this sort of thing.
https://www.tlc-direct.co.uk/Products/FXKVR50.html

Size will depend on how large the SWA needds to be.

cheers. Any rule of thumb what you can get through different sizes? I hear armoured cable is not the easiest to run. I think we're looking at 25mm though I might be misremembering as it's late!

 

[333rocky333]

What ever duct you use put a rope through it prior to burying, flexi duct comes with a draw wire, but i still prefer using that to pull a more sturdy blue nylon rope in