I somehow thought this wasn't going to be a 'helpful' thread...
Whilst I accept there are a lot of botched and potentially dangerous DIY jobs around there are also people perfectly capable of rewiring safely and legally in compliance with the relevant regulations.
As some of those reading this will know I have recently started a DIY rewire of my own, this is being done in compliance with relevant regulations and I really appreciate the advice and assistance offered by forum members, here and elsewhere both in the public forum and outwith it.
The attitude that no-one other than an electrician is capable of rewiring a house, installing a new circuit, adding an outlet to an existing ring final circuit, changing a light fitting etc is not helpful. DIYers coming here and asking questions are doing one thing right for starters - they accept they *don't* know exactly what to do and for that reason are asking advice.
My view is that you can dismiss these people with 'call an electrician' and, in many cases, they'll try and undertake the work themselves anyway.. or you can offer guidance and advice.
Teach a man to fish and all that...
The problem is that rewiring a house is not quite the same as replacing a light or adding a socket, and there's a huge danger with people attempting to learn what they need to know by asking questions on an internet forum, because they will only ask about the things they realise they don't know. Subjects where they know nothing and don't even know they know nothing because they have no idea that the subject even exists they won't ask about - the old unknown unknowns problem.
IMO people shouldn't even wire up a light switch on the basis of following instructions to insert-this-wire-in-that-hole without genuinely understanding why and how it all works.
So yes DIYers can of course do a complete rewire, but to do so they have to know how to do
all of the things involved - how to size circuits, how to calculate voltage drop, how to calculate cable current carrying capacities, how to calculate fault loop resistances, how to choose CPDs, how to route, join, and support cables... the list goes on and on.
They also have to know how to do, and to be able to actually do, full testing before and after energising.
No reason why anybody can't learn all of that, but it's hard to see how someone could do so just by just asking questions about things they think they need to know.
There are useful questions - but to be asked of the person wanting to do something as major as rewire a house or replace a CU, and they really should be able to answer them all positively.
I'd appreciate anybody's comments:
- For a circuit to supply a given load, how would you go about deciding what cable and protective device to use?
- Do you know which circuits can be ring finals and which cannot, and what the advantages and disadvantages of each are?
- Do you know what the two main lighting circuit topologies are, and what the advantages and disadvantages of each are?
- How do you calculate maximum demand and how can diversity be used?
- What are the 3 different types of domestic single-phase supplies provided in this country, how would you recognise them, and what differences do each make to the requirements for the rest of the installation, particularly any outdoor supplies?
- Can you correctly identify all components and connections of a circuit by method of testing or otherwise? In doing so can you identify or recognise anything wrong or dangerous with the circuit?
- Do you understand how the way in which you install cables affects how much current they can carry?
- What are the rules concerning cables concealed in walls, partitions and under floors?
- What are the rules for cables run outdoors, buried in the ground or overhead?
- Where cables need to be joined, how should this be done / not be done and in what circumstances are different methods acceptable?
- Can you identify extraneous conductive parts, and do you know the requirements for main and supplementary bonding of them?
- Which circuits should be RCD protected?
- How do you propose to isolate your supply so that you can connect up your new CU?
- Do you know what tests you would carry out on the installation - what sequence you'd do them in and at what point you would energise the installation, and for each test do you know what is being measured, why it is important, how you would carry out the test, and with what equipment, and what sort of results you would expect to get if everything was OK?
By all means teach a man to fish, but be aware you may also need to teach him how to navigate and how to sail.
) to use for X" then it's a little different but "I want to replace my fuse box, how do i do that" or words to that effect is a little different imho (e.g. asking for advice/clarification vs a step by step how-to / where do i start...)
