I have a couple of henley blocks on my incoming electrics board located after the meter. The henley blocks have seals on them. (The incoming electrics run through the meter, through henley blocks to the CU) I need to change my consumer unit, so I would like to open the henly blocks up and connect the new CU tails.
Is it illegal to open these seals even though they are placed after the meter?
Thanks in advance for your help,
Best regards
Mark Wilmott
MY feeling is that in a lot of cases, Henley blocks have seals put on them 'because there is a place for them'.
However, you make no mention of any isolator, so I would guess that they are there to make people think twice about opening them, since there is no real way of making them 'dead' short of pulling the main fuse. It is dangerous to work on the tails live, the problems not just being with shock, etc.
Of course, if you're pulling the main fuse anyway, that's different (but that would be breaking a seal too, and you didn't mention that one). The general consensus seems to be that the leccy board don't worry much about it these days.
Again, you could have an isolator immediately after the meter, but you don't mention it.
Just cut them off and chuck 'em away. I had just this situation a week or two ago. Took seals off henley block after meter and on the main fuse before it. I then changed the CU. However I noticed the elec company's short cable from the incoming cable to main fuse had perished insulation. So I called them out to replace it. When they came they made no mention of the seals being removed. Neither did the meter reader
If the Blocks aren't needed anymore, then take them away completely and put the new tails directly between the meter and the new consumer unit.
or replace one with an isolater...
There isn't an isolator, but I was under the impression that it would be reasonably safe to do this live, since you would only be working with one wire, which would only become live once it inserted into the henley block?
Whilst I've worked with live wires quite often I think I'd draw the line at working with a live wire which had an almost limitless current capacity and no human-friendly protective devices downwind.
Slightly different matter when you've got an RCD on the circuit protecting your arse.
YMMV.
PoP
Sending email to my published email address isn't guaranteed to reach me.
I agree. I'd want to be more than 'reasonably safe'....!
I guess provided the first thing you do is remove the one tail from one henley block and then put the cover back on and tape over the hole. Then do the other it wouldn't be to bad as you don't have a free end of 25mm cable waving about with 240v on it.
Getting the new tails in might be fun 25mm cable is not the easiest stuff to work with. I know I was swearing fairly loudly at the last lot of 16mm I had to deal with and that was ona fully dead system. Not sure I'd want to do it with this big exposed lump of brass directly connected to the mains in front of me.
Pull the fuse, the boards don't appear to care anymore. What would you prefer 6' under or a slapped wrist?
Replaced both my dodgy consumer units by withdrawing the tails from the unsealed Henly block - if that is what the Bakelite box with two stacked busbars is called. I used a seriously insulated screwdriver to undo each tail in turn and then refitted the cover. Removed and replaced the consumer units and mounting board. Remade new tails and then refitted them to the Henly. All without removing the company seal.
This was all done after watching the bod from the Lecy board replace the company fuse by hammering the tar filled remains off the incoming cables (live) without any protection apart from the wooden handle of his hammer (and plenty of practice!).
BOL Richard
PS he didn't seal my Henly block.
I'd do it live if I had to, then again, I do it day in day out so that's not really an issue. If you're asking a questions on NG about electrics probably best not to do it live!!
SJW A.C.S. Ltd.
True, last one I did was a 3 phase job, phoned Scottish Power, "Just cut the seals and do it, phone us when you're done and we'll come out and reseal it."
Most new installations seem to have isolators.
If I get that sort of call (i`m one of their phone monkeys) I arrange for an isolator to be fitted.
IIRC I did suggest that but they weren't interested. Not sure there was room without major alterations. Huge old house, 3 ph supply, electric underfloor heating. Only private house I've ever seen with a "switchroom".
How much do you charge to fit an isolator ?
Precisely nothing.
If its a Scottish Power area Dataserve will usually sort them out for you (the new name for the metering dept.), but if you need a cutout change then the relevant operations dept (Power Systems) for the area will fit one at the same time as changing it.
The preferred method is one of the above, but if its a rush job then
*sometimes* we can arrange another way (without saying how, and it doesn`t include cutting the seals yourself !)HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.