New tncs supply, 16mm ok?

[trevmai]

I had a job to look at today where someone had set fire to some rubbish in an intake cupboard. Uk power networks have dug up some of the road and disconnected the incoming tncs supply. They will not run a new supply until a new armoured cable has been installed and tested. I was thinking of installing a 60amp wylex isolator supplying 16mm 3 core swa. The run is about 15m long. Is there any problem with this or will the swa need to 25mm?

 

[RF Lighting]

Who will be signing the EIC for the job? It's up to them to design the installation and calculate the cable size required.

 

[trevmai]

I will be signing off the cert. The cable is more than adequate for the 60amp fuse. Was just wondering if uk power networks would insist on 25mm. The disconnected tncs cable to the house looks as it may only be 10mm max.

 

[plugwash]

Personally I'd say fit a switchfuse rather than just an isolator. I belive some DNOs don't like it if you rely on their fuse to protect your cable.

I'd also use 3 core SWA so that a 16mm earth was incorporated.

 

[securespark]

Are they asking you to replace the underground cable from the road??

 

[trevmai]

I'm going to install one of these with a 3 core 16mm swa coming from it.
Uk power networks are going to replace the underground cable from the road but the want my cable run and tested before they do anything.

Untitled

• trevmai
• 24 Jul 2013
• 1

 

[JohnW2]

I'm going to install one of these with a 3 core 16mm swa coming from it. Uk power networks are going to replace the underground cable from the road but the want my cable run and tested before they do anything.

It's probably me being dim, but what side of the meter is this switchfuse and SWA going? I realise it would normally be on the consumer's side, but some of the things you say make me wonder. I also wonder what 'testing' they are expecting you to do on this (presumably brand new) bit of SWA.

Kind Regards, John

 

[trevmai]

The switchfuse and swa will be on the suppliers side of the meter. I will be doing an r1+r2 and IR test only as there will be no power.

 

[Lectrician]

Suppliers side? Are you sure?

 

[chris765]

So you are saying the meter/s are not in the intake cupboard?

What property type? Flats - http://library.ukpowernetworks.co.u...0118+Supplies+to+Multi-occupied+buildings.pdf

 

[JohnW2]

The switchfuse and swa will be on the suppliers side of the meter. I will be doing an r1+r2 and IR test only as there will be no power.

That's what I suspected from what you wrote. This is something beyond my experience - it presumably isn't a 'simple' premises. Who are you working for - property owner or what? Who is gping to be the 'owner' of this (pre-meter) SWA after you've installed it?

Kind Regards, John

 

[chris765]

In my experience with UKPN I think they will want you to convert to a submain.
I don't believe they will like a switch fuse before the meter as it's a point that can be tampered with. Unless they can seal it.

I think they are expecting the meter to be moved to the cupboard so the cutout can be connected to the meter in tails and then it will be up to you?

 

[JohnW2]

I think they are expecting the meter to be moved to the cupboard so the cutout can be connected to the meter in tails and then it will be up to you?

That's what I would have expected, which is why I asked the question. Admittedly my experience is very loimited, but what we're being told seems a little odd. Indeed, if (for whateverreason) there ever were a need to have a long distance between cutout and meter, I would have thought that the cable between them would be the responsibility and work of DNO and/or meter operator, not the consumer (hence my question about who the OP was working for).

Kind Regards, John

 

[Lectrician]

I think the OP has got the wrong end of the stick.

 

[JohnW2]

I think the OP has got the wrong end of the stick.

As you probably realise, that was my impression - but, as a non-electrician, who am I to say so?! - hence I just 'asked a few questions'

Kind Regards, John