100A DP Isolator Installation Between Meter and CU

[jaydub]

Hi guys,

When installing a new CU does anyone ever install a 100A double pole isolator switch between the meter and the consumer unit?

Very often I come across 16mm tails which need to be upgraded to 25mm so I join the old tails to new in a Henley block and get the DNO to come and upgrade their side at their convenience.

Instead of using a henley block could I use an isolator instead?

In anyones opinion would there be any disadvantages to this?

I wouldhave thought having an isolator would be very handy but the meter guys hardly ever bother putting one in, even now.

They're also relatively inexpensive. Another thing, I cannot seem to finda 2-module metal enclosure so would this would be okay in a plastic enclosure? That to me seems like a bit of grey area.

Any help appreciated. Thanks

 

[brynmor steel]

Any local spark can do this.

Local sparks can't isolate the DNO fuse

 

[brynmor steel]

It depends on the DNO's policy really.

Strictly speaking the sealed equipment is owned by the DNO or the billing company so only they should make changes there, but many DNO are OK with registered electricians doing it and some even provide temporary seals, etc.

What the DNO is really concerned with is folk trying to bypass meters to seal the supply, and the danger of pulling the main fuse to isolate if there is anything dodgy about the cut-out condition as shorting the incoming supply is going to end your day very badly. This is the sort of example to show the danger of working on a live supply:

They had proper PPE and probably were OK, their underpants probably less so.

So ask local electricians about it, they ought to know if the DNO is agreeable and/or if they already have permission to do that.

This is why I've asked, if I get a local sparky who hasn't permission to remove the DNO fuse it could end up a bit nasty.

 

[Michaelwgroves]

This is why I've asked, if I get a local sparky who hasn't permission to remove the DNO fuse it could end up a bit nasty.

This has been over complicated for you, albeit all the comments after mine are all correct.
Engage a local electrician, he needs to ask the DNO to remove their fuse so he can install isolator. Once the work is complete they come back to install fuse and seal.
Some DNO's will allow the electrician to do this, but he needs to call to check.

 

[Taylortwocities]

Local sparks can't isolate the DNO fuse

Depends on the DNO. The DNO here (SSE) permit registered electricians to do this, with a load of provisos.