isolator between cu and meter

[Knighty]

i have increasingly heard this is a good and safe way of working on your CU. So would a Wylex IP65 Enclosure with a 100amp double pole isolator switch disconnector inside do the job.

 

[Screwi]

You should have an isolator in its own enclosure before the CU - so when the isolator is off you can work safely inside the cu without any danger - if you have the isolator in the cu - part of the incoming side of the isolator will still be live inside the cu!,

In short have an isolator before the cu from the meter tails.

 

[Knighty]

yes what you say is right in between CU and Meter, but will what i have named be ok to put in between the CU and meter

 

[andy]

yes what you say is right in between CU and Meter, but will what i have named be ok to put in between the CU and meter

yes. but be aware youll have to pull the fuse or work live

 

[securespark]

Something like this:

But don't expose the coloured inner insulation, that was the engineer's doing, not mine...

 

[Knighty]

Thanks for all the advice, that looks just like what i was trying to describe. I may have to work live as the local leccy company will charge me to pull their fuse, but i would rather feed and terminate a live cable into an isolator than a fiddly consumer unit or am i being stupid.I know there is a risk but it will mean i can work on my new CU in the future in (safe mode) with the isolator in place.

 

[andy]

Thanks for all the advice, that looks just like what i was trying to describe. I may have to work live as the local leccy company will charge me to pull their fuse, but i would rather feed and terminate a live cable into an isolator than a fiddly consumer unit or am i being stupid.I know there is a risk but it will mean i can work on my new CU in the future in (safe mode) with the isolator in place.

only work live if you know what your doin. just remember, there is only a 60A+ fuse protecting you if it goes wrong. no 6AMCB, no RCD etc

EDIT: youll have to break a seal if the tails form the meter are undersized.

 

[lord nicon21]

Thanks for all the advice, that looks just like what i was trying to describe. I may have to work live as the local leccy company will charge me to pull their fuse, but i would rather feed and terminate a live cable into an isolator than a fiddly consumer unit or am i being stupid.I know there is a risk but it will mean i can work on my new CU in the future in (safe mode) with the isolator in place.

i can see were you are coming from but how are you going about doing it live ?

 

[Adam_151]

But do they charge your for having a blown fuse replaced?

...I'll fetch the kettles...

 

[Careful_Bodger]

I don't think working live is a particularly good idea, personally. Having done a similar/same (DIY) job, the thought of manipulating live tails into the cramped confines of the enclosure (it is small inside) and thence into the isolator itself would give me the willies. I really would not do this.

Pulling the fuse might the less cr4p of two bad choices. You don't plan to steal electricity, and you can demonstrate you were working to improve the electrics. Beware though, the sparky that pulled mine wore rubber gauntlets, and a full face guard. We made sure the main switch was off, with no load on the system. (There is a possibility for an embarrassing shower of sparks, or a welded fuse holder if you get this bit wrong with a large current flowing).

For a very old system you might remotely possibly need a contingency plan in case the fuse holder disintegrates as it is pulled. Has happened apparently.

There is not really too much mystery about this, as far a I can see. I re-fitted the fuse myself, and the sparky didn't even give it a second look.

Ideally, you then need to find someone to reseal the fuse holder - but then the advice I have seen (this forum, etc.) is that the RECs really don't care too much as long as there no real problem and no real abuse.

HTH,
CB

 

[Knighty]

to be honest im thinking of breaking the seal and pulling the service head fuse to be on the absolute safe side but worried when the meter reading man comes round and says ello,ello,ello whats all this.Will i be in big trouble?

 

[Careful_Bodger]

I have the benefit that my fuse is in the outside meter cabinet, over which I have absolutely no control in the event that a scallywag may wish to some and interfere with me (as it were). I can (try) to deny it was anything to do with me, guvnor.

You might wish to check though that the meter man is not likely to be coming down your driveway while you are in mid pull (as it were again - oo er missus ).

 

[towman]

You might find that the REC will charge to pull and refit service fuse, but if you say that you want an isolator fitted for ease and safety of carrying out electrical work and upgrading to CU etc, they'll come and do that for free! Certainly eastmidland/central networks do. It's worth asking anyway.
Wouldn't try working live - those big 'ol tails don't bend that easy and spot welding the supply together isn't a great idea!

 

[plugwash]

whilst we don't advise diyers to pull the fuse i think most people here would agree its FAR safer to pull the fuse than to work live.

if you do decide to pull the fuse make sure that all main switches in the CUs are off so no current is/will flow (this is important BOTH when pulling the fuse and when reinserting it)

also make sure you touch only the bits of the fuse carrier that were intended to be touched (ie the bits you can see/touch when its fully inserted)

finally if the fuse carrier looks in any way damaged or badly correded DO NOT ATTEMPT TO PULL IT.

 

[ban-all-sheds]

I may have to work live.

Under no circumstances should you do this.