I'm looking at replacing my old fuse box with a new consumer unit with more MCB ways.
The three I'm considering are: MEM Memera range MK Sentry range Wylex NH range
Quality is more important than cost. Any of you experienced users out there care to put them in a 1(best)-2-3(worst) order in terms of quality.
I'll probably go for a metal clad unit, on the basis that it will be more durable.
Any comments based on personal experience would be really helpful.
Thanks Pandora
I'm happy with my Contactum. The RCBOs are double width, but quite cheap, which is good when you are buying several.
The MK Sentry would appeal as single width RCBOs are available, although quite a lot more expensive.
I couldn't find RCBOs for the Wylex at the time (although they do exist, at least in double width form) and the boxes were too small.
I've not seen the MEM stuff.
If you have TT earthing, you should use an insulated unit, unless you intend to mount the 100mA time delay RCD externally.
Christian.
Do you know if any of these have a cartridge fuse option for some circuits (ie lights)?
TIA
Andy R
I personally favour Hager but that's not on your list so we'll skip that!
1) MK are related with quality items and their consumer units are no exception, they seem to stand the test of time, I come across them quite a lot in pubs for some reason! There is also plenty of wiring space within the unit's, making installation a doddle, theoretically! 2) The MEM are reasonable, I've fitted quite a few and haven't had any problems with quality issues. However they're not the easiest to fit, can be a little faffing involved to get the job done 3) The Wylex is probably the more dated, I personally haven't come across as many newer type Wylex units as any other brands. I don't think they have the range of extra's the MEM and MK have, (timers, aux modules etc...), so would probably steer clear for this reason although I have fitted a couple in recent years and have been pleased with quality.SJW A.C.S. Ltd.
All of them.
SJW A.C.S. Ltd.
Wylex and Hager do them. I don't think MK do. Not sure about the others. It wasn't a concern for me, as I have energy saving lighting. Many people report better behaviour with a Type C MCB. However, even one of these could blow with a halogen or candle bulb (but then so can a cartridge fuse).
Christian.
So MK do them? I couldn't find them in their catalogue.
Christian.
The nicest quality I've used is MEM Memshield 2. I've used it in both domestic and commercial situations -- it's slightly over the top for domestic but if you're after a high quality metal unit, it will certainly do. The box will cost some extra, but the breakers and switches are no more than for any other CU. You should be able to buy from just about any electrical wholesaler -- this is a very common range used commercially. I notice MEM do different ranges of breakers for the Memshield 2 and the Memera ranges, so be careful you get the right ones (never tried using wrong ones, so I don't know what the difference is).
I'm not very impressed with MK's current plastic CU's. There's nothing wrong with them, but the cases aren't the same high quality as most of the rest of MK's product range. Their previous style was slightly better. Not used a metal one. The switches/breakers to go in them are fine though.
Now you come to mention it, I've just looked in my catalogue and they don't actually. To be on the safe side I checked the Wylex and MEM catalogues, they do them for sure. I think MK stopped doing HRC options then, I seem to remember seeing them. If you're experienced enough you can get other HRC's to fit, but don't try this with just any, some don't fit properly. Told you, bad year !!
SJW A.C.S. Ltd.
Had to get you back somehow! ;-)
Christian.
I've used entirely MK Sentry stuff as I've replaced consumer units (main one in house, subsidiary ones in a workshop and each of two garden buildings).
The quality is good and there is plenty of space to dress the cables properly.
It's a good idea to plan a larger unit than you think you will need because the difference in price between sizes is not great and it's then easy to add more MCBs and other devices later. I arrange mine to have some spare ways each side of the RCD.
.andy
To email, substitute .nospam with .gl
Hagar still do them regards fitting - some just need the case aperture filing a bit but some don't seem to be exactly DIN standard and won't grip the rail properly
I was informed that a troublesome circuit would benefit from a type D MCB which is a bit like putting a nail across a fuse carrier - it'll never trip unless you can supply enough current. Better to not use incandescent lighting at all if possible
The problem with type D is you need a very good Zs to comply. I have tested commercial installations, mainly shops with a lot of display lighting, with type D's and failed them on to high of a Zs for the CPD. Changing them to B's or sometimes C's at a push is usually the answer. Basically if you use D's you need to make sure there is an absolutely fantastic earth path and that every joint on all connections are as near to zero resistance as possible.
SJW A.C.S. Ltd.
Hope you don't mind if I tag another question on this thread.
I have TT earthing and the CU I fitted in 1984 which has just the one 30mA RCD (also acting as the main isolator) and 8 Type B MCB's. I want to change the CU to a split load one, with a 100mA time delayed RCD and a second 30mA RCD for GF sockets, garage etc. Two questions please:
1 Can I use the 100mA RCD as the main isolator? None of the manufacturers seem to list the box and 2 RCD's as a standard item. They all seem to have the 30mA RCD and a simple 100A isolator switch. Can I order the components individually?2 Can I reuse my old MCB's? They are MEM but I notice the current MEM ones have different shape switches. Also, mine are rated 6A, 16A, 32A and 45A which appear to be out of date.
Thanks Peter
Yes, most manufacturers do time delayed split load consumer units, not a lot of info online though, easily available that is! As I keep mentioning I use Hager. Ask at a local electrical wholesaler, or a few of them, depending where you are depends on their stock levels but most will be able to advise if there are non on the shelf.
If they are the ones I am thinking of, (grey MCB's, not as tall but deeper than newer MCB's, little black switch), then no, you can't. Also, who said 6 16 and 32 amp ratings were out of date, that's the ratings of all new MCB's.
SJW A.C.S. Ltd.
"Lurch" wrote
Ok - I need to buy 8 new MCB's ;o( Is it just because they're a different shape, or are they different in any other way? (eg different BS?) Just curious. Seems like a rip off if they just change the mountings to fit the new cases.
Sorry Lurch, my mistake. My lighting MCB's are 5A, not 6, but if I have to buy new ones then the question becomes academic!
Thanks for your help.
Peter
Without going and digging one out of the stores I couldn't tell you exactly. They will have a different BS no. but that's not to say they aren't up to scratch with regard to charecteristics of the operation. It does have quite a lot to do with new BS standards requiring a complete redesign of the MCB but more often than not it's the manufacturers idea to totally change the externals as well. FWIW a Hager time delayed CU complete MCB's will set you back about £200 + vat, add to that other mats like meter tails, new earth rod, box etc.. The MCB's are a few pounds each, not really a great chunk of the overall cost once you start to add it up so not as bad as it could be.
That sounds more like the one's I'm thinking of.
SJW A.C.S. Ltd.
Also you'll likely have little or no discrimination with the upstream protection device. So in a shop, a fault on one lighting circuit could lose you the whole lot, which really isn't a good idea in a public access building.
Lurch wrote
I was hoping to reuse the tails and the earth rod, (especially the rod, as it was a right B to get into the chalk round here!) The tails are 16mm² double sheathed - is that OK? The earth conductor from the rod up to the earth block is also 16mm² green/yellow sheathed. I'm not sure if it's mech protected - it's in an MDF duct. This was all installed in 1984 and AFAIK it seems up to current regs.
Yep - they are definitely grey ones.
Do I really need to do all this? It seems unnecessary to me but I'd appreciate your advice. Somebody told me my system is out of date and needs upgrading but, although it is not to current regs, it seems to me a 30mA RCD serving all circuits has to be safer than 100mA. I do understand the split load thing about the lights going out, but we never have any nuisance tripping. The RCD did once have a spell of phantom tripping which I traced to a nick in the PVC sheathing just inside the french windows, where rain gets blown in sometimes. The only other time it tripped was once when I got a neutral to earth short pulling a cable through a box knockout.
Thanks Peter
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