Is this CU safe to fit in that case?
Wylex Consumer Unit replacement help.
- Thread starter Benny5
- Start date
Is this CU safe to fit in that case?
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There may be problems replacing mcb's etc. The aperture tends to be the same but the internal sizes vary - especially the depth to a busbar that connects live to everything. That may mean replacing the lot if one fails. Over time it will probably become clear what can be used in them as there are loads of them about.
The RCD's are standard types - unlikely to be a problem. Some items can draw what looks like DC through them which can upset this type.
I haven't noticed anything that says surge protection has to be fitted - some one might provide the number of a reg that stipulates they must be fitted. I have looked at the performance of them and will continue to plug an espresso machine I have into an add on protected socket. Spike suppression is NVG via the surge protectors. The machine uses triacs, designed some years ago and these can fail in usec via spikes on the mains. Many new electronic bits and pieces have this protection built in. Spikes do crop up far more regularly on the mains than surges. However I will have surge protection fitted when and if we have a new cu fitted.
Worst comes to worse you do have a good quality well designed empty cu at pretty good price and it may still be possible to fit a surge protector.
About £250 - depends on what is fitted and what it costs and hourly rates. There are often very good offers about on populated CU's for instance and there has been better
https://www.toolstation.com/axiom-m...tegrity-dual-rcd-10-mcbs-consumer-unit/p82853
What I want will cost more and will probably say I want Contactum due to comments from electricians a long way from me that can't do the work. I'd prefer an MK casing though.
The RCD's are standard types - unlikely to be a problem. Some items can draw what looks like DC through them which can upset this type.
I haven't noticed anything that says surge protection has to be fitted - some one might provide the number of a reg that stipulates they must be fitted. I have looked at the performance of them and will continue to plug an espresso machine I have into an add on protected socket. Spike suppression is NVG via the surge protectors. The machine uses triacs, designed some years ago and these can fail in usec via spikes on the mains. Many new electronic bits and pieces have this protection built in. Spikes do crop up far more regularly on the mains than surges. However I will have surge protection fitted when and if we have a new cu fitted.
Worst comes to worse you do have a good quality well designed empty cu at pretty good price and it may still be possible to fit a surge protector.About £250 - depends on what is fitted and what it costs and hourly rates. There are often very good offers about on populated CU's for instance and there has been better
https://www.toolstation.com/axiom-m...tegrity-dual-rcd-10-mcbs-consumer-unit/p82853
What I want will cost more and will probably say I want Contactum due to comments from electricians a long way from me that can't do the work.
I'd prefer an MK casing though.
Last edited:
There may be problems replacing mcb's etc. The aperture tends to be the same but the internal sizes vary - especially the depth to a busbar that connects live to everything. That may mean replacing the lot if one fails. Over time it will probably become clear what can be used in them as there are loads of them about.
The RCD's are standard types - unlikely to be a problem. Some items can draw what looks like DC through them which can upset this type.
I haven't noticed anything that says surge protection has to be fitted - some one might provide the number of a reg that stipulates they must be fitted. I have looked at the performance of them and will continue to plug an espresso machine I have into an add on protected socket. Spike suppression is NVG via the surge protectors. The machine uses triacs, designed some years ago and these can fail in usec via spikes on the mains. Many new electronic bits and pieces have this protection built in. Spikes do crop up far more regularly on the mains than surges. However I will have surge protection fitted when and if we have a new cu fitted.
About £250 - depends on what is fitted and what it costs and hourly rates. There are often very good offers about on populated CU's for instance and there has been better
https://www.toolstation.com/axiom-m...tegrity-dual-rcd-10-mcbs-consumer-unit/p82853
What I want will cost more and will probably say I want Contactum due to comments from electricians a long way from me that can't do the work.
Just spotted these CU's still for sale at Screwfix and Toolstation so I'm confused.
https://www.toolstation.com/mk-meta...MI3Ibnn-Wf6AIVVuDtCh18SQjdEAQYAiABEgI0cvD_BwE
https://www.screwfix.com/p/mk-sentr...ed-split-load-main-switch-consumer-unit/2186g
https://www.toolstation.com/mk-meta...MI3Ibnn-Wf6AIVVuDtCh18SQjdEAQYAiABEgI0cvD_BwE
https://www.screwfix.com/p/mk-sentr...ed-split-load-main-switch-consumer-unit/2186g
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I also made a mistake, my CU manufacturer at this time only makes 6A RCBO type A, all other sizes are type AC only, I hope in the future I will be able to get the other types, but to be frank not really worried if they stay as type AC I am sure they will trip, the inverter fridge/freezer, freezer, and washing machine are unlikely to cause a problem.
That sort-of figures. As has been said, MK stopped making CU's (and components/spares for them) a while ago, so everyone is probably trying to get rid of any stocks as quickly as they can!
Kind Regards, John
Given that these are still available and they must also have an extensive installed base I'm fairly relaxed. I'll see what the Electrician has to say when I get round to getting it done. Following this afternoons announcements on the current crises it could be some time away.
Thanks to all for your various contributions.
Regards, Benny.
So long as it all works, it would be fine - even though MK have gone down a lot it recent years, they remain one of the fairly 'reputable' manufacturers. However, if any of the parts ever require replacement, it will be difficult/impossible to get any MK replacements - and, although it's probably what would be done, using non-MK ones is not something that one really should do.
Kind Regards, John
443 and 534, which together comprise 17 pages of regulations. Plus Annex A443 and B443, and Appendix 16.
'Standard' type AC RCDs are very likely to be a problem, and a large majority of connected loads will cause problems.
Type AC RCDs and RCBOs are only suitable for purely resistive loads. They have already been banned in many countries because they are next to useless in modern installations.
Indeed - but I'd be intrigued to know whether anyone actually is installing surge protection (other than if they by pre-populated units that already contain it) in domestic installations.
I have to say that, given that we have lived without it since the birth of electrical installations, I'm far from convinced that it is something that is every going to be 'significantly necessary' in a domestic environment.
Kind Regards, John
Until relatively recently, electrical installations were not stuffed full of electronic equipment that is easily damaged by transient overvoltages.
True, in many cases - but how common an issue do you think that really is?
Speaking personally, I've lived with plenty of electronic equipment for a good few decades, and can't think of a case in which it seemed particularly likely that some damage may have been caused by transient over-voltages (and, when goes back in time, the electronics were probably even more theoretically susceptible to such damage than they are today).
Anyway, what about my question - are people actually installing this 'protection' in domestic environments to any significant degree?
Kind Regards, John
I haven't looked that closely at must fit them but have read " fit subject to opinion the electrician based on what they see plugged in" - read expensive HiFi etc- red rag to a bull to me. I have no interest in a chapter in the regs I want to see a must fit which would be in section 4 where musts tend to be mentioned. Buy a loaded CU and generally it will have one fitted now.
I have looked at the performance. Surges yes, spikes, no way, well short of what is needed. We used to get regular surges here. Lights would dim and then bang come back on often taking a bulb out. One blew up a dimmer, literally cracking it's facia. They seem to be strongly associated with Leylands main factory night shift. Never late, more late evening.
For my sins I was tasked with fitting mains monitoring gear on the power to a computer. Spikes up to the mSec level were pretty frequent - industrial area. Some also uSec level and odd one 10msec or so. Volts - 1000 and higher. 500+ common.
The problem turned out to be the crap software running on it or more correctly the person that wrote it. No surges as such over a couple of weeks of monitoring, just spikes.Many many electronics are now fitted with MOV, metal oxide varistors to protect them from spikes even self generated ones on switch mode supplies. The sizes used are dirt cheap and handle spikes rather well. They are also used in suppressed extension lead and plug in units that achieve the same thing.
Don't go to sleep reading this
My espresso machine uses triacs to drive certain things. When ever an engineer replaces one of the things that are driven this way they also replace the triac board. Triacs are pretty robust things providing they are sensibly rated but they hate over voltage. The small mov's are very good at suppressing spikes so I plug in via one of those. Also a commercial style bean grinder as I can see that this has no spike protection built in and the electronics in it failed.The surges and spikes are caused by loads making the very high voltage supply lines drop due to loads. They tend to recover pretty quickly and the capacitance in sub station transformers cause the change to be transferred directly to the output. Surges usually relate to fuses and breakers opening somewhere under fault condition and can be far more severe. We have not had a severe surge for a long time now, Leyland have gone - spike type ones - pass but may have cause the grinder electronics to fail.
Whilst I admit that I haven't had reason to look very hard, I got the impression that such is still very much the exception, rather than the rule.
I’ve had an SPD in my CU for over 15 years. BS7671 is the minimum standard you must work to, not the maximum.
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