Armoured and mdpe

Redjeff · May 27, 2020

Evening,

I am supplying services to my detached garage. I have laid a 750mm trench for the mdpe pipe, back filled ready for the armoured cable to go on top.
I am bringing the mdpe pipe up under my patio which has a purpose built storage area underneath (with t-bar construction) then carrying it through into the house. To get the pipe under the patio, I have had to core drill under steps which was not exactly easy.

The question is, can I bring the armoured cable through this same hole then seperate the two once through?

I'm currently getting quotes to do the electrics, but I want to get this cable in and get the garden back to normal first.

Thanks for your help
Lorne

James · May 27, 2020

I cant see a problem with what you intend to do.

pc1966 · May 27, 2020

Agreed, it looks perfectly OK.

Hopefully you have already been through the calculations for the cable size, etc?

You should make sure the spraky is happy with the cable (type, rating, supplier, etc) before you commit to it as ultimately they are looking at signing off on the whole system.

ChipFanDave · May 27, 2020

I would bring both the MDPE pipe and the SWA up through the cored hole in separate hockey sticks. This protects the bend radius and the individual services from the concrete. Also makes them easy to tidy up internally.

Redjeff · May 27, 2020

Thank you very much guys.

Yes I have already talked to the sparks, both are happy with 16mm. I am also getting them to change the consumer unit as well whilst they're at it, seems an obvious thing to do as it's an old Crabtree rail type.

David Prosper: When you say hockey stick, what do you mean by that? Is it like flexible duct?

ChipFanDave · May 27, 2020

No mate they are rigid. Just google them pretty much any supplier will have them or get them in. This is for the SWA you get simular ones for MDPE they can be either just another pre-made bend pipe fitting or for the pipe to pass through.

Redjeff · May 27, 2020

Ah got you, I've just normally used some drain pipe, but being preformed would be easier.

Thanks for your help

pc1966 · May 28, 2020

Redjeff said:
Yes I have already talked to the sparks, both are happy with 16mm. I am also getting them to change the consumer unit as well whilst they're at it, seems an obvious thing to do as it's an old Crabtree rail type.

If you are going for 16mm cable then I guess you are planning for a fair amount of power, so I expect your sparky will be splitting the meter tails to provide a separate fused-switch feed for the detached garage in that case as it makes sense to do it at the same time as a CU change.
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Redjeff said:
Ah got you, I've just normally used some drain pipe, but being preformed would be easier.

The main advantage is they already honour the minimum bend radius for the typical cables the DNO would use, and that is fairly similar to your 16mm SWA.