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As per Title, if you are installing Home EV charging, are going to install an Isoilator Switch between the meter and the CU and will also install Henley Blocks to split the supply off to a min CU for the EV charger, there is a better way.

Basically use a Dual Supply 100A rated Contactum Isolator switch (Wylex brand). No Henley Blocks required!

Here's a link to one.

Dual Supply REC Switch (tlc-direct.co.uk)

Instead of using the switch as a Dual Supply, it can be easily converted to singe inlet (Neutral and Phase) and Dual outlets (2 linked Neutrals, 2 linked Phase). No extra parts are required.

The saving is a significant reduction in space required in a (tight) meter cabinet and reduction in high current joints.

Change the labelling of course!

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That's neat.
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Just need to make sure it gets wired correctly; the main CU side is rated 100A whilst the mini CU side is 40A.
 

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A Henley Block before any switch does make easyer to work live if needed to replace switch as easy access to screws etc.
 

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A Henley Block before any switch does make easyer to work live if needed to replace switch as easy access to screws etc.
It does, provided that it's not one of those dreadful double decker ones. I hate those, always have, and always fit SP Henleys,even though they take up very slightly more room. However, mention of live working to the new breed of ultra-sensitive young people calling themselves electricians will likely have them picking up the phone to have you arrested. I did it a while ago, just put on gloves and face shield to work live on something very simple and the young lad next to me went ballistic. I pointed out that the word electrician meant that he was qualified to work with electricity, not dead bits of plastic and metal.

It seems that they are (quite sensibly) stressing the importance of locking off and proving dead to these youngsters, but aren't teaching them to use judgement and balance risk against inconvenience to the client. Isolating a supply is obviously the first choice, but in the present times there are people working from home that cannot have their internet connectivity down whilst work is done, so it makes sense to try and use safe alternatives to do the work without causing the client to have a major inconvenience, and, perhaps, incur a significant cost.

Pulling a live tail out of a Henley is a safe enough thing to do if done carefully by someone that understands the risks and mitigates them. As @freddym mentioned in another thread, it does make you wonder if any of these super-safety conscious youngsters ever stop to think why all their tools are insulated and approved to withstand working on live circuits.
 

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Do they? Surely they pull the supply fuse
Part of thier job is replacing main fuse holders and also with sub meters etc the main fuse can't be removed without cutting power to other users. And when disconnection for none payment if fuse holder is left it is easy for people to reconnect themselves.
 

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I don't know about current practice, but years ago if a meter was removed for non-payment the head was also removed and the incomer capped so that there was no easy way to reconnect it. For years there have been modified fuse holders for sale that have a terminal that connects to the incoming side, these are very popular with the small scale cannabis grow farms that get set up in empty houses. They bypass the fuse and meter and allow an easy, plug in, connection directly the the supply.

Normal practice for a straightforward meter change, if there is nothing criminal involved, is to pull the fuse to isolate the supply.
 

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In the part of London my dad run 30 years ago, he got his staff to remove the fuse holder and cap the cable, the cannabis farmers did not like having to cut a cap off a live cable.
 

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In the part of London my dad run 30 years ago, he got his staff to remove the fuse holder and cap the cable, the cannabis farmers did not like having to cut a cap off a live cable.

I went out to look at the way that a main had been connected into to power a fairly big grow farm last year. They must have had some fairly professional people connecting things up, as they had tapped into an underground run of 95mm² (whilst it was live) and were drawing around 150 A from the supply for the lights, pumps, fans etc. The cable they had run was undersize (16mm²) but they had made a good job of the torpedo joint as far as I could see. Even the DB they had set up to wire the place up was reasonably well wired up, and it was clear that it had been done by someone with at least a basic understanding of what was needed.

It looked as if it had been a well organised, commercial scale, criminal operation, so presumably they had some competent people to do all the setting up work, although as far as I know none of those people have yet been caught. From what I heard, the people arrested were those doing all the day to day work at the place and they were practically slaves, mostly illegal immigrants that were being paid peanuts and given some pretty squalid accommodation on site, in old caravans. The DNO had already been in and cropped all the illicit cables and made good their main, but the cut out section of it with the joint the criminals had put in was left there to be tidied up by the site owner. Heck of a mess, as there were ongoing arguments as to whether all the work needed to clean the place up and make it usable again (as an industrial unit) was covered by the insurance or not. The insurers were apparently arguing that the site hadn't been properly secured last I heard.

Years ago, I remember being called late at night by a friend to go out and try and restore power to a cottage he was letting out, as the tenants reported a power cut. I got there to find that they were lucky the place hadn't burned down, as the main fuse had been replaced by a short length of copper water pipe. The resulting overload had very luckily burned out the incoming cable at the head. I had nothing more to do with it, and left it to the owner to sort out with the electricity board (as it was then) and his tenant. Judging from other burn marks underneath the meter tail entries, I strongly suspect that his tenant had been trying to bypass the meter, got it badly wrong and blown the main fuse, replaced that with the bit of pipe, then had another go, got it wrong again and blown the incoming cable. Must have been a hell of a bang and flash each time. My guess is that the tenant was too stupid to realise that the neutrals are both in the centre of a meter connection, and the lines at either end.
 

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Nice one, Mike, and great to see a commercial electrician with a YouTube channel, gives a lot more insight into the "dirty" end of the trade!

No it was 50 miles or so from there, but a very similar set up from the look of it and could easily be the same gang I think. The farm/industrial site I went to they think was related to the really massive grow just up the road from me at Chilmark a couple of years ago, another one where I think they never caught the people behind it: Nuclear bunker raid finds £1m cannabis farm. The rumour is that the same organised gang are running loads of these big commercial grows, but they are clever and make sure their identity remains hidden and the foot soldiers on site, often illegals or homeless people they treat as slaves, are the ones that get caught.
 
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