Mains Isolation Switch - in external white box

[Jupiter01]

The white box housing the meter currently has a fuse which I understand - needs to be pulled by an authorised person - before electricity can be reenergised into house.

I would like an isolation switch in the white box which then means that there is no electricity (when set to off) coming into my Consumer Unit and I can safely work inside it for any maintenance that I want to do.

Do I request this from EDF (my supplier) or someone else and is there a plausible explanation which can get me this for free??

Thanks in advance.

 

[thomp1983]

If you ask your supplier for a smart meter more often than not you can get the installer to fit one for free if you supply it.

Or like a large amount of people who've been in situation before you could pull the fuse yourself and fit your own isolator before replacing the fuse, if you chose to do this Id suggest you look into the possibilities of what can go wrong so you are aware rather than just yanking it out any old way

 

[RandomGrinch]

...or contact your DNO, who may do the work for a nominal fee...

 

[JohnD]

I fitted my own, I asked the DNO how to go about it, and they made an appointment for (I think) a meter fitter who pulled the fuse and came back an hour later, to reenergise, no charge.

I provided new 25mm tails and a 100A DP switch and enclosure, which I screwed to the backboard, and I think he also fitted my new 16mm earthwire which I had fitted to a bigger MET block, or maybe I did it myself later.

@thomp1983 is I think referring to the fact that fuseholders, especially if very old or having overheated, sometimes break when pulled, occasionally with undesirable consequences.

 

[JohnW2]

If you ask your supplier for a smart meter more often than not you can get the installer to fit one for free if you supply it.

In fact, my supplier fitted an isolator for free when undertaking a "routine change" of my 'dumb' meter, and actually declined to use the isolator I offered him, instead installing an identical one from his van (again, at no cost to me)!

My daughter's (again 'dumb') meter has a built-in isolator, and I wonder why that is not more common?

Kind Regards, John

 

[JohnW2]

...or contact your DNO, who may do the work for a nominal fee...

Maybe it varies between DNOs, but mine are seemingly not interested in anything downstream of their cutout, and won't touch anything downstream of the meter.

Kind Regards, John

 

[RandomGrinch]

Maybe it varies between DNOs, but mine are seemingly not interested in anything downstream of their cutout, and won't touch anything downstream of the meter.

Kind Regards, John

Mine - Western Power, installed it for me, when I wanted a rewire.
This was a few years ago now, and we all know that a lot can change in a few years!

 

[Taylortwocities]

Or like a large amount of people who've been in situation before you could pull the fuse yourself and fit your own isolator before replacing the fuse, if you chose to do this Id suggest you look into the possibilities of what can go wrong so you are aware rather than just yanking it out any old way

As well as the potential dangers of doing this, @Jupiter01 please remember that to do this you would have to cut off the supplier’s seal on the main fuse. This is not permitted by your supply contract.

 

[Jupiter01]

UPDATE: EDF will replace this FoC and it will be done within the next 3 weeks. That’s what I have been informed.

Over the years and with immense support from many of you on this forum, I’ve done lots of electrical projects. I have grown in confidence and also enjoy this. Thanks again.

I’ve always stopped short of doing anything inside the Consumer Unit. Once this switch is in place, I am hoping to familiarise myself with this too.

Think I have this right…
Without this main isolation switch, once the main isolator on the CU is switched off (and safe isolation has been carried out), everywhere inside the Consumer Unit is dead apart from the incoming meter tails as show in this image I.e. it is safe to poke around everywhere else?



Once the additional isolator is installed and once safe isolation has been carried out, this will also be dead?

On safe isolation, can I replace the prove dead unit test with testing my 2 pole tester on a known circuit?

Thanks again

 

[Jupiter01]

Can I please get your thoughts on my last post please?
I think I have this straight in my head but would appreciate your validation.

Thanks in advance.

 

[Taylortwocities]

Yes your post is correct. Only comment is that you will be unable to carry out the final stage of the safe isolation process (ie checking your voltage indicator still works) once you have isolated the incoming supply. As there will be no supply to test against. that is the purpose of a proving unit.

 

[JohnW2]

Yes your post is correct. Only comment is that you will be unable to carry out the final stage of the safe isolation process (ie checking your voltage indicator still works) once you have isolated the incoming supply. As there will be no supply to test against. that is the purpose of a proving unit.

Whilst that is clearly true, and represents the (virtually foolproof) safe isolation practice one should undrtake and advise, I wonder how often it is actually done in the real world (i.e. other when someone is being 'assessed')?

Over the years and decades, I've watched a large number of electricians working. Many, maybe most, (but not all) 'test for dead' after isolation. Of those, many (maybe most) 'prove' their tester on the available supply before isolating it. However, I'm not sure that I can recall ever having seen one undertake that 'final stage', and I'm not even sure how many of them actually have a 'proving unit'.

If that final stage is omitted, they are, of course, undertaking a fairly 'safe gamble', since it's incredibly unlikely that their tester will suddenly develop a fault in the few seconds, or whatever, immediately after they effect the isolation.

If one (or two) people are able to observe the tester whilst the isolator is opened and closed a couple of times, that's probably approaching the ideal.

Kind Regards, John

 

[CBW]

Over the years and decades, I've watched a large number of electricians working. Many, maybe most, (but not all) 'test for dead' after isolation. Of those, many (maybe most) 'prove' their tester on the available supply before isolating it. However, I'm not sure that I can recall ever having seen one undertake that 'final stage', and I'm not even sure how many of them actually have a 'proving unit'.

I have a proving unit, and at first was using it after receiving my safe isolation training, now it’s just an ornament in the back of the van. None of our sparks use proving units (that I’ve seen them use anyway). It’s probably breaking company procedures too. Most of my work is isolated locally, eg boiler spur for a pcb change, so not worth locking off either. Nor do I check it’s isolated, as, if I turn off the fused spur and the boiler goes off, then I’ve confirmed it’s dead visually. If I’m working on a circuit that’s in a different location, then will usually lock off.

 

[JohnW2]

I have a proving unit, and at first was using it after receiving my safe isolation training, now it’s just an ornament in the back of the van. None of our sparks use proving units (that I’ve seen them use anyway). It’s probably breaking company procedures too. Most of my work is isolated locally, eg boiler spur for a pcb change, so not worth locking off either. Nor do I check it’s isolated, as, if I turn off the fused spur and the boiler goes off, then I’ve confirmed it’s dead visually. If I’m working on a circuit that’s in a different location, then will usually lock off.

Thanks. That corresponds with my experiences/observations and expectations.

Kind Regards, John

 

[Jupiter01]

I have a proving unit, and at first was using it after receiving my safe isolation training, now it’s just an ornament in the back of the van. None of our sparks use proving units (that I’ve seen them use anyway). It’s probably breaking company procedures too. Most of my work is isolated locally, eg boiler spur for a pcb change, so not worth locking off either. Nor do I check it’s isolated, as, if I turn off the fused spur and the boiler goes off, then I’ve confirmed it’s dead visually. If I’m working on a circuit that’s in a different location, then will usually lock off.

Does switching off at the Fused Spur meet the safe isolation requirements? I thought it required a lock-off. Or are we still talking about the real-world