Domestic meter tail isolator

[Soulsurfer]

Hey all,

I have a few installs coming up where I need to upgrade cu's and want to install isolators between DNO service head and new consumer units. I have only ever fitted before to twin supply houses on off peak storage heating and was under the impression that a straight enclosure with a 100A DP main switch would be good enough. But DNO have just told me that they also require over-current protection. On two supply i usually use a Hager 4P switch and 2 x 63A MCB's for feed tails but could I use a 100A dp and a separate MCB in enclosure on Brown tail ? or does anyone use easily sourced different equipment?

Thanks,

 

[TJ Anderson]

Interesting isn't it

 

[TJ Anderson]

Interesting isn't it. We will be expected to fit a AMD3 metal type KMF in the white box. Yet can guarantee the DNO can still fit thier 60947-3 in small insulated DIN enclosure in very same white box as they don't work to BS7671.

 

[davesparks]

Some meter operators will refuse to work in a meter cupboard which contains exposed earth metal due to the greatly increased risk when working live.

 

[Midwest]

...I've also been using fire rated grommets for cable entry, is that another "LAW"??

Yep, another urban myth;
https://www.youtube.com/watch?v=nJvLT7uwO58 at 13.20m.
You just need to maintain the correct IP rating.

If you want to spend money, you can buy this stuff, like Wylex are trying to flog;

http://www.electrium.co.uk/media/20151123152849_0_Wylex NMFS Inturnescent.pdf

 

[nickblake]

They look nicer than their CU's

Not when they have 2 whacking great wisk glands securing the tails and wont fit in most scenario's

 

[Midwest]

Not when they have 2 whacking great wisk glands securing the tails and wont fit in most scenario's

Still look better than their CU's, perhaps they will have a facelift!

 

[Soulsurfer]

Any ways had to go supposedly fit new CU & main isolator as good practice yesterday & upon removing old Bakelite & wood 3036 board found 5 x extra circuits and a 2 way lighting circuit linked by the twist together & tape up method behind the ply section really nasty stuff and to top it off no main earth from TN-S MET & no bonding at all to incoming water ! What code would you all put on this ? DNO just laughed & said good luck on a Friday mate & fitted new meter & tails I provided to 100A switch fuse & then left !. Customer away til tonight so nothing more done as no access to property as key was supposed to be left & not.

 

[Risteard]

What code would you all put on this ?

You can't put any code on an Electrical Installation Certificate. The certificate declares that the work carried out is compliant with BS 7671:2008 (2015).

As such the only course of action would be to correct it.

 

[Paulgwat]

Doing a job the other day where a main fuse disintegrated in the bosses hand - called SSE out to sort and asked them to fit double pole isolator while they were there as we would be adding an additional cu and didn't want to faff with getting the new fuse re-sealed later in the day. - SSE said talk to metering outfit, nothing to do with them as DNO - he did however give us an isolator switch off his van to fit ourselves though!!

both hanger and Wylex both do a switch in a housing specifically for this application - my interpretation of the rules is that this would be allowable inside an external meter box even though it is plastic, just not inside a property.

personaly I fitted a control gear switch fuse in a metal housing (tails borderline on 3m and a bit) - huge compared to the old plastic MF but was only about 35+vat - build quality not great though.

Hager and Wylex both sell the din rail fuse holder and relevant bits to make an amnd3 compliant solution but it ain't cheap!