RCBO's

[circles]

I may be asking some very stupid questions from time to time and this is probably one of them. But anyway my background is in electronics and not electrical work so I have zero knowledge of the correct terminology for many electrical items, nor do I have much knowledge with regards to current regulations.
Anyway to my question about about RCBO's, does any manufacturer produce an RCBO that you can push into the very old Bakelite fuse box sockets? (Not sure what the correct term for those are) You'd think that with a modern type consumer box with an RCD there wouldn't be such a great need for individual RCBO's, as fitting an rcd in series with another one has an effect on how fast the rcd trips. However, I would have thought that there would be a fairly large need for push in RCBO's as those old fuse boxes aren't protected by RCD's at all, yet they are still found in many homes.
Anyway, if they are being produced, could someone please point me in that direction? Thanks

 

[DurhamSparky]

Answer to that Q is no! none at all...! all you can get is Push in MCB made by wylex and GE

your answer to RCBO and RCD question about inline etc is this...! you dont fit a RCBO when a RCD is already fitted..! and truthfully i can see RCBO becoming more popular as time goes on and price comes down as a dual RCD has potenially 5 circuits it can trip were as a RCBO has 1.... im fitting a 8 way box soon with 8 RCBO inside it!

 

[malcolmsanford]

The old Wylex for example the 3036 board had rewireable fuses and you are able to get the plug in MCB to convert these fuses to MCB.
AFAIK there have never been convertable plug in RCBO's or RCD for these boards.

I'm trying to rack my brains why there would not be a RCBO plug in for these made. Technically I can't see a reason. It may be a cost thing which do sometimes govern these issues. There indeed maybe a technical issue which is escaping me I'm sure if there is someone will point that out

 

[sjm]

In order for the RCBO to work in the old wylex boards you would have to completely re-configure the wiring to allow neutrals through the RCBO. I think this would prove to be impossible as your connections would be outside of the enclosure.

 

[circles]

Thank you Durham Sparky and Malcolm for your replies. For safety there most definitely isn't any reason at all why there shouldn't be a push in RCBO. In fact, those old boxes are crying out for them really because anyone receiving an electric shock has no protection at all.

Makes you think with all this PC correctness going on, that the one place that you'd think they'd make healthy, live saving decisions and actually be helpful for a change, they completely miss. They are probably too busy making rules about not offending someone, somewhere by painting a wall in a building the wrong colour.

It's like being in school, we are all taught when the battle of Hastings was fought. We have all gone around with 1066 in our heads for donkeys years, yet they could have just as easily taught everyone what size fuse should be put in plugs, which would have saved some lives and prevented numerous fires.

 

[circles]

In order for the RCBO to work in the old wylex boards you would have to completely re-configure the wiring to allow neutrals through the RCBO. I think this would prove to be impossible as your connections would be outside of the enclosure.

Ahhh...yes I knew there would be a good reason for it...... I'll have to take a closer look at how these things are fitted as I said before I've got some theory but none of the practical.

 

[telectrix]

main reason is as sjm says. also it's more cost effective to replace the old rewireable fuse board with a dualRCD or RCBO board. fitting RCBOs in a 3036 board would be like fitting airbags in the Hindenberg

 

[malcolmsanford]

Think it is really a cost and practicality issue and SJM is quite right. It's fairly straight forward to change a rewirable fuse and carrier for a MCB and carrier. The process is perhaps a few minutes and you just have to make sure that your Zs values are acceptable after the alteration.

To convert the rewirable fuse to an RCBO will virtually mean dismantling and reconfiguring an outdated board, where you can now buy a dual split or high integrity board for less than 100 pounds.

Also as all CUs now have to come under Reg 530.3.4. in that they need to meet BS EN 60439-3 with the short circuit test described in annex ZA. In fact I would be amazed if any electrician would change your rewireable fuses to plug ins now. As he would need to drastically upgrade the board to meet the regs and standards.

 

[DurhamSparky]

main reason is as sjm says. also it's more cost effective to replace the old rewireable fuse board with a dualRCD or RCBO board. fitting RCBOs in a 3036 board would be like fitting airbags in the Hindenberg

what!!! even fitting fireproof ones!!??

 

[circles]

Well thanks everyone, I've learned a lot already.