What isolator switch do I need?

[emphasis303]

Hi guys

British Gas are coming out tmrw to fit an isolator switch for my mains...so I was told.

I called them up tonight to see if I needed to provide the switch or I do, and they said that I have to actually get an electrician to fit one and they are just going to cut the power between 8 and 1n and put it back on between 1 and 5.

So the question is, what type of switch do I need to buy?

I thought something along the lines of this one

http://www.screwfix.com/prods/53010...comers/Wylex-100A-DP-2-Module-Isolator-Switch

But I am not 100% sure as where would I house this unit.

If anyone can let me know what type I need and also link to a website with one or a shop it would be great.

Thank you

 

[Spark123]

Yeah, that is the sort of thing they use. You will need a 2 module enclsure to house the isolator too such as http://www.screwfix.com/prods/32311...Consumer-Units/Wylex-IP40-Insulated-Enclosure

 

[ban-all-sheds]

You'll need tails as well.

 

[JohnD]

that would do. you also need a 2-way enclosure to put it in. If you can't get one, use a 4-way and use two blanks so there is no finger access.

It is conventional to have power in at the top and out from the bottom.

the earth wire does not go through it, but provide a new 16mm G&Y if it's undersized.

New tails s/be 25mm. Put rings of coloured tape or cable tie in brown/blue near the ends to identify P and N (the sheathing should not be stripped back outside the enclosure so you will not be able to see the coloured insulation).

The isolator is commonly mounted on the backboard with the meter, although technically only the DNO's equipment should be on it, they don't usually mind an isolator, Henley, and earth block. Any Henley should be downstream of the isolator.

If the fitters don't like that idea, you can fit it on the CU backboard (if you have one). IMO these items are better on a board than screwed to the wall (which may not be perfectly flat and cause the enclosure to distort

Make a durable label saying "Main Switch". Unless you have a label maker, you can make quite a good one with white marker tape and a permanent pen.

Here is an example done some time ago (note old colours)

View media item 819

 

[dullSpark]

Rather like JohnD (I think) I would recommend the MEM isolator/enclosure as shown in his photo.

These are particularly useful because they have a small hatch where the outgoing terminals only can be accessed.

I picked one up on ebay for a very reasonable price the other day.

 

[JohnD]

The MEM hatch is great!

View media item 820

 

[kwikfix328]

Scottish Power ( Dataserve) came out to my house to fit an isolator to my house just over two weeks ago. I then had a sparky in to remove my existing 24 hour & economy 7 CU's and replace them with a single split load CU.

The Scot Pwr geezer fitted a Wylex unit. The top half is sealed and the bottom half has a removable cover revealing the 2 cable sockets.

Iwent from this:
http://photos.imageevent.com/sidand...rgashpiccys/large/METER SERVICE HEAD REV1.JPG

to this:
http://photos.imageevent.com/sidand...oundforgashpiccys/large/Isolator Fitted 2.jpg

to finally this:
http://photos.imageevent.com/sidandcoke/generaldumpinggroundforgashpiccys/large/SG1L0992.JPG

 

[emphasis303]

thanks a lot guys for all the help

As i posted quite late I didnt want to have to rush everything tmrw, so I went to screwfix and purchased the following

http://screwfix.com/prods/29235/Electrical/Cable/Meter-Tails/6181Y-25mm-Meter-Tails-Blue-Grey-5m

http://screwfix.com/prods/82604/Electrical/Cable/Meter-Tails/6181Y-25mm-Meter-Tails-Brown-Grey-5m

http://www.screwfix.com/prods/74436...its/Wylex-IP65-Insulated-Enclosure-With-Visor

http://www.screwfix.com/prods/80187...s/MK-MCBs-Incomers/MK-100A-DP-Isolator-Switch



I did purchase the enclosure that sparky 123 linked to however the knockouts wernt big enough, so i purchased the more expensive one and drilled through the top with a holesaw and fixed it to the top left of the meter backboard as there was no space anywhere else.

I already have Henley's and my earth block on the board so they can take a running jump if they say anything.

Im going to be changing all the old tails aswell since I have so much cable, and the old ones are black and red.

I will post pics once its all done.


thanks for the info johnd about tails not being cut back outside of the box to show the colour, I would of done that lol. But is it ok to cut them back within the enclosure?


Thank you very much to everyone, I dont think Ive got such a fast reply from so many people. must of been the time

 

[kwikfix328]

How come you are having to do all this stuff yourself ?

I got all my work done by Scottish Power for free via my supply company ( Atlantic Electric & Gas ), I just phoned them up after seeing a post on this discussion board and a few weeks/phone calls later it was done.

 

[JohnD]

yes, you can cut back the grey sheathing once inside the enclosure. The sheathing is intended to give a second layer of protection over the insulation; but the enclosure does that too. Be careful not to nick the insulation when you do this.

You should find that embossed on the isolator is an indication of the length of stripped wire you need to reach into the terminal without exposed copper showing.

In the same way, sheathing has to be taken into enclosures such as consumer units, junction boxes, switch and socket boxes.

I think the enclosure you have bought is supposed to have plastic cable glands fitted which tighten round the cable, but if you have drilled accurate holes I suppose that will be OK unless it is going to be splashed with water or you can poke anything down the gap. Holes in the top of enclosures are supposed to be sealed against anything falling in.

 

[emphasis303]

lol ahhh ok, im not sure what plastic at the top you mean, but I think it had a knockout at the back but as I needed to insert 4 25mm tails there was no way it would fit nicely against the backboard with the 4 so I just drilled accuratly with the holesaw.

If you could link to a site or shop the correct plastic glands I will need that would be great.

Thank you

 

[JohnD]

like this

http://www.screwfix.com/prods/91684.../Weatherproof-IP66/IP66-Cable-Gland-Pack-of-2

the glands tighten round the cable as you screw the tops down. This gives added security against being tugged if someone knocks into the cable or drops a ladder on it. I think they fit a standard 20mm knock outs but there must be 25mm ones as well.

You can also get a sort of rubber grommety thing that seals round the cable, provided you cut them really acccurately.

I would have expected you to have two holes in the top and two in the bottom.

25mm tails are pretty stiff so the holes need to be aligned with the terminals inside

 

[Deleted member 54734]

How come you are having to do all this stuff yourself ?

I got all my work done by Scottish Power for free via my supply company ( Atlantic Electric & Gas ), I just phoned them up after seeing a post on this discussion board and a few weeks/phone calls later it was done.

I was wondering that too.

If somebody told me they were coming to put me a switch in i'd expect THEM to have the switch and to fit it overwise what are they coming to do?

Times look wrong too.

I get AM (0800-1300) and PM (12.00-1700) appointments

Usually 7-8 jobs in the morning and 7-8 jobs in the afternoon.

Maybe the girl you spoke to has confused you?

 

[kwikfix328]

In fact thinking about this further, the guy who came out to do my work told me that not only was he only supposed to fit equipment supplied to him by Scot Pwr, but that he also had to use the official tools that they provided too ! I presume this is a safety/insurance thing.

This was mentioned in our conversation because on his first visit he broke his big insulated screwdriver trying to undo some corroded connection screws and had to get a new one off the company...

 

[JohnD]

I think the job has been scheduled as a "pull fuse so customer electrician can make a connection" job

Not as a "Fit isolator" job.