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How to wire up a consumer unit

A semi-detached house has a prehistoric fuse box with rewirable ceramic fuses. It will shortly be replaced with a modern consumer unit. The existing circuits are:



 



1. Lights



2. Upstairs sockets



3. Downstairs sockets



4. Kitchen sockets



5. Cooker



6. Shower



 



The following circuits will be added to the consumer unit:



 



7. Central heating



8. Burglar alarm and CCTV



9. Outside lights



 



I have been informed that the best choice is a split load consumer unit with two RCDs and space for RCBOs. My intention is that circuit 8 has its own RCBO but what is the optimal way to allocate circuits to RCD A and RCD B? Also, should any other circuits have their own RCBO?



  • Morgaine Dinova:

     The Institution is supposed to be a promoter of engineering education and a role model for professional ethics in UK engineering, not a money-grabbing outfit focussed on its own profit above all things.




    There are times when I think it is yet another swanky London club considering the prices it charges for membership and technical publications.

    https://en.wikipedia.org/wiki/List_of_gentlemen%27s_clubs_in_London




    Open publishing is thriving, while the proprietary publishing model is widely condemned in the sciences and many other disciplines. In contrast to these advances in knowledge dissemination, putting engineering standards behind a paywall is taking UK engineering back to the medieval days of shady masonic guilds protecting their trade secrets for their own profit. It's astoundingly bad on numerous grounds, particularly in respect of discouraging education, limiting public knowledge of legal requirements, impacting on public safety, and in making "information only for the rich".




    This reminds me of how Asperger Syndrome was only known about in Britain and other English speaking countries during the 1980s by a tiny elite group of psychiatrists. Lorna Wing published a paper titled Asperger's syndrome: a clinical account in the February 1981 edition of Psychological Medicine, which was the first reasonably in-depth article about Asperger syndrome written in English.

     



    http://www.mugsy.org/wing2.htm

     



    She made no efforts to raise awareness of Asperger syndrome in the wider medical community or amongst teachers and educational professionals by writing any books or articles for more mainstream publications. For example, if she had published an article about Asperger syndrome in the Times Educational Supplement then she would have reached out to a wide audience of people who deal with children on a daily basis. For 10 years the only significant English language article about Asperger Syndrome remained hidden away in an obscure academic journal. The Maudsley Hospital where she worked was the only place in Britain that could diagnose a person with Asperger Syndrome until the 1990s. When Lorna Wing died in 2014 obituaries published in newspapers made references to her groundbreaking paper but I doubt if any journalists knew about the existence of the paper during the 1980s.


    Uta Frith translated Hans Asperger's papers from German into English during the 1980s and she published the book Autism and Asperger Syndrome in 1991. This book was remarkable because it specifically used the term Asperger Syndrome in its title as opposed to just autism, and it was written in a style that was designed to be easily understood by parents and teachers who had never studied psychiatry - as opposed to being a highly technical publication that only professional psychiatrists are able to properly comprehend. The result is that Uta Frith, rather than Lorna Wing, is usually regarded as the person who made Asperger Syndrome public knowledge in Britain and English speaking countries.


    Is history repeating itself at the IET?


  • The proposed wire up is:

     

    7. Central heating (MCB)



    2. Upstairs sockets (MCB)



    3. Downstairs sockets (MCB)



    RCD 63A



    9. Outside lights (MCB)



    4. Kitchen sockets (MCB)



    5. Cooker (MCB)



    RCD 80A



    8. Burglar alarm and CCTV (RCBO)



    1. Lights (RCBO)



    Main Switch




    With the central heating breaker on the LHS and the main switch on the RHS. Circuits 4, 5, and 9 are protected by the 80A RCD. Circuits 2, 3, and 7 are protected by the 63A RCD. Future higher current or outside circuits will be connected to the 80A RCD and future lower current inside circuits will be connected to the 63A RCD. Future critical circuits will have their own RCBO.


    Can anybody fault this wire up?

  • Morgaine Dinova:

     I found it hard to believe that these standards are a secret in the UK, and worse, that they are hidden behind an IET paywall so that only those with money can learn about them. In the absence of contrary information so far, I am sadly concluding that Arran and Simon were right.


    This is not what I would have expected from the IET, and is incredibly short-sighted. The Institution is supposed to be a promoter of engineering education and a role model for professional ethics in UK engineering, not a money-grabbing outfit focussed on its own profit above all things. Secrecy has no place in engineering standards, nor in engineering education, and it runs counter to informing students (or simply knowledge-seekers) about professional and legal requirements in installation wiring and setting a good example....

     




    Remember that the Wiring Regulations are a British Standard (BS7671) and the IET are selling it under licence from BSI. If they were to provide it for free it would be breach of copyright. I don't know of any National or International Standards (e.g. BS, DIN, NEN, IEC, etc.) that are provided free.

    Alasdair


  • Alasdair Anderson:



    Remember that the Wiring Regulations are a British Standard (BS7671) and the IET are selling it under licence from BSI. If they were to provide it for free it would be breach of copyright. I don't know of any National or International Standards (e.g. BS, DIN, NEN, IEC, etc.) that are provided free.

    Alasdair


    It disgusts me how many botched, and potentially dangerous, electrical installations are out there carried out by DIYers and cowboy sparkies who do work for friends and family. Even professional qualified electricians are not always on the ball or up to date with their knowledge, especially when faced with new or unconventional situations. If professional and legal requirements for electrical installations were more easily available for a lower price then it would go a long way towards ensuring that electrical installations are safer and up to date with industry practices. 

     

  • Another question is whether time switches, contactors, kWh meters etc. associated with a particular circuit should be located as close as possible to the MCB / RCBO for that circuit or should they be located on one side of the consumer unit and the MCBs / RCBOs located on the other side?
  • Former Community Member
    0 Former Community Member

    Morgaine Dinova:

    I've waited a few days since Arran Cameron's and Simon Barker's answers to my question requesting links to online documentation about UK wiring standards for consumer units, hoping that someone might provide a link to the online resources. I found it hard to believe that these standards are a secret in the UK, and worse, that they are hidden behind an IET paywall so that only those with money can learn about them. In the absence of contrary information so far, I am sadly concluding that Arran and Simon were right.


    This is not what I would have expected from the IET, and is incredibly short-sighted. The Institution is supposed to be a promoter of engineering education and a role model for professional ethics in UK engineering, not a money-grabbing outfit focussed on its own profit above all things. Secrecy has no place in engineering standards, nor in engineering education, and it runs counter to informing students (or simply knowledge-seekers) about professional and legal requirements in installation wiring and setting a good example.


    The Internet has made information on virtually every topic more and more available with every passing year, and now even encompasses legislation and interacting with one's own government. Open publishing is thriving, while the proprietary publishing model is widely condemned in the sciences and many other disciplines. In contrast to these advances in knowledge dissemination, putting engineering standards behind a paywall is taking UK engineering back to the medieval days of shady masonic guilds protecting their trade secrets for their own profit. It's astoundingly bad on numerous grounds, particularly in respect of discouraging education, limiting public knowledge of legal requirements, impacting on public safety, and in making "information only for the rich".


    This is an area that calls out badly for IET modernization and reform.


    Thank you Arran and Simon for your input.


    Morgaine.




    I don't wish to hijack the topic, but this statement does require some challenge.


    I'm sure you can appreciate that any publication has significant production costs attached to it and it needs paying for. The IET would be unsustainable if it were to give away everything for free without money coming in to support its activities.


    We run over 1500 knowledge events every year and the vast majority of those are free. We have something like 150,000 people attend them, so money from publishing and other surplus-generating activity does get re-invested; there are no shareholders to pay.


    We do also have an open access journal: http://digital-library.theiet.org/content/journals/joe 


    I'm not going to argue that the IET is perfect, but the accusation of money-grabbing and profit above everything is unfair. The annual report is transparent and anybody is free to examine where money comes from and what it's spent on.


    In the interests of not derailing the original post, I'd suggest starting a seperate topic and / or refer you to the annual report and a browse of the website to understand the scope of the IET. I appreciate your point of view and frustration, but perhaps it's borne out of a lack of knowledge of what else the IET does.

     


  • Arran Cameron:




    Morgaine Dinova:

     The Institution is supposed to be a promoter of engineering education and a role model for professional ethics in UK engineering, not a money-grabbing outfit focussed on its own profit above all things.




    There are times when I think it is yet another swanky London club considering the prices it charges for membership and technical publications.

    https://en.wikipedia.org/wiki/List_of_gentlemen%27s_clubs_in_London




    Open publishing is thriving, while the proprietary publishing model is widely condemned in the sciences and many other disciplines. In contrast to these advances in knowledge dissemination, putting engineering standards behind a paywall is taking UK engineering back to the medieval days of shady masonic guilds protecting their trade secrets for their own profit. It's astoundingly bad on numerous grounds, particularly in respect of discouraging education, limiting public knowledge of legal requirements, impacting on public safety, and in making "information only for the rich".




    This reminds me of how Asperger Syndrome was only known about in Britain and other English speaking countries during the 1980s by a tiny elite group of psychiatrists. Lorna Wing published a paper titled Asperger's syndrome: a clinical account in the February 1981 edition of Psychological Medicine, which was the first reasonably in-depth article about Asperger syndrome written in English.

     



    http://www.mugsy.org/wing2.htm

     



    She made no efforts to raise awareness of Asperger syndrome in the wider medical community or amongst teachers and educational professionals by writing any books or articles for more mainstream publications. For example, if she had published an article about Asperger syndrome in the Times Educational Supplement then she would have reached out to a wide audience of people who deal with children on a daily basis. For 10 years the only significant English language article about Asperger Syndrome remained hidden away in an obscure academic journal. The Maudsley Hospital where she worked was the only place in Britain that could diagnose a person with Asperger Syndrome until the 1990s. When Lorna Wing died in 2014 obituaries published in newspapers made references to her groundbreaking paper but I doubt if any journalists knew about the existence of the paper during the 1980s.


    Uta Frith translated Hans Asperger's papers from German into English during the 1980s and she published the book Autism and Asperger Syndrome in 1991. This book was remarkable because it specifically used the term Asperger Syndrome in its title as opposed to just autism, and it was written in a style that was designed to be easily understood by parents and teachers who had never studied psychiatry - as opposed to being a highly technical publication that only professional psychiatrists are able to properly comprehend. The result is that Uta Frith, rather than Lorna Wing, is usually regarded as the person who made Asperger Syndrome public knowledge in Britain and English speaking countries.


    Is history repeating itself at the IET?



     




    IMO I would use DP RCBOs if cost is no problem plus I would use a M/C DB larger than the standard domestic sized.

    See the link below for your introduction.

    https://www.electricalsafetyfirst.org.uk/mediafile/.../Best-Practice-Guide-6.pdf

     

  • Re- "The Institution is supposed to be a promoter of engineering education and a role model for professional ethics in UK engineering, not a money-grabbing outfit focussed on its own profit above all things."


    There have always been numerous publications aimed at those applying the Wiring Regulations from many different sources. These would include, material used by colleges and other training establishments, guides issued by engineering institutions, employer groups , trade associations, accreditation bodies, trades unions and especially manufacturers/suppliers much of which can be also be found on-line gratis.   

     

    The IET has been the coordinating body responsible for wiring standards in UK buildings since it was The Society of Telegraph Engineers & Electricians in the early 1880s ,although it is a very long time since this activity occupied the majority of members.

     

    In my experience the Wiring Regulations themselves are used as source of authoritative reference and/or more difficult or complex situations where judgement/argument is required. Most Electricians don’t need routinely to refer to the regulations at work because they are familiar with what is relevant to them from initial/refresher learning. Those of Eng Tech, JIB “Technician” or supervisory responsible standard usually have a strong understanding, familiarity with were to seek further information and how to interpret it. Some of them post in the IET Wiring & Regulations Forums.          

     

    On the subject of consumer units, I understand that the Fire Service pressed for changes to enclosures in the last regs revision following some fires being propagated from arcing and overheating within. Under UK Building Regulations installation of Consumer Units should be carried out by, or at least certificated by a competent person as defined by current registration through an approved scheme. The IET does not currently operate such a scheme, although some members and Engineering Council professional registrants are also members of approved industry schemes.  

     

    As part of its duty to serve our members involved in electrical installations within the scope of the Wiring Regulations and hopefully attract more of a high standard in future, The IET should of be listening and improving where it can. Unfortunately Morgaine I found your critique too generic, are you working in this field and if so what information are you seeking that you allege IET is “hiding”? I would support making information that has potential to improve the quality of electrical installations readily available. However work being carried out by untrained people, who may have gained knowledge, but lack the essential attributes of practical good workmanship and real relevant experience, would create more hazards not fewer.

     

    I argue in a different thread that an advanced apprenticeship expected of electrician , isn’t “inferior” to a degree, they just come from different ends of a continuum between practical and theoretical (aka vocational v academic), intended to optimise people for different roles. However, many experienced Engineers especially within this field of work end up meeting somewhere in the middle.   

  • I don't know if you have done this job yet and the new regulations have been published since your original post. 


    There is a culture of installing more circuits than are required in consumer units that don't really serve any purpose. Consumer units and MCBs are cheap as chips leading to more MCBs than being installed than is actually required.


    If you follow the recommendation to install arc fault detection devices at around £120 each then the consumer unit you are proposing will cost over a thousand pounds, I'm sure that will really focus your mind on how many circuits you really need. 


    You also need to ensure that you install type A RCDs and as a absolute minimum on the kitchen socket circuit or else you may have issues with a washing machine. 

    Regards the regulations book, it is not a how to guide book and if you have a copy it won't give you an answer to the question asked here.


    Remember installing and replacing consumer units is a regulated practice, so those who are deemed capable of undertaking the work should have the knowledge and skills to design and install a consumer unit. It is not something that should be undertaken by someone who has Googled how to do it to find a set of instructions. 


    I have some gripe with the current system and I'm expecting changes, but the publishing of the electrical regulations on the internet as a free to view is not something I can envisage happening. 


    It would make more sense for the DCLG to publish a domestic electrical installation compliance guide to run alongside of part P of the building regulations, but domestic installations are getting too involved with equipment such as solar PV, storage batteries and vehicle charging for a simple guide book to be published. Some of the domestic installations are very involved. 


    Andy Betteridge.
  • A DCLG compliance guide would be a free to view resource on the internet, it would also be out to the direct control on both the BSI and IET, so it would be a whole new ball game.


    Andy Betteridge