I know nothing, I can only change the face plates on switches and sockets, and change light fittings. Even then I'm sweating in case I blow up, mains is off for all of it, rather than a particular circuit.
That is really a good example, theory says you should never work on anything live, OK some exceptions for DNO and also testing is not counted as working! and neutral is considered as a live wire, so only way in most domestic premises is to turn off all power, next is HSE say you must isolate elsewhere, isolation using an isolator built into the panel your working on is not good enough, so with domestic in most cases that would mean drawing the DNO fuse. In real life this is not how you do it, you should also protect yourself from ionisation of the atmosphere which yes DNO workers do with huge rubber gloves and the rest of the PPE kit.
In real life we are aware of the dangers and we act in a way to minimise the danger, not wearing nylon for example, but also there are so many pit falls, for example did you know they put graphite in the rubber of wellingtons to stop you getting static build up, so wearing wellingtons does not protect you any better than normal boots.
My son did domestic then after a time he got into industrial, I asked him last week would he return to domestic, he answered no way unless forced. There was a time when domestic electricians were paid by the house for wiring them, and those able to work fast could earn a lot of money, those days are gone. At one time the central heating was the most complex electrical job for domestic electricians, they were considered as the lowest form of electrician, we called them house bashers, those days have also gone, some of the systems used today are getting quite complex. OK as yet the domestic electrician does not carry a laptop as part of his tool kit like the industrial lads, but it is coming, it will not be long before it is part of standard tool kit, it is getting that way now.
The house I am in now has the central heating controlled by the laptop, and even the odd light switch and socket.
When I started maths was only used in collage, once at work you could forget it, today very different, I have sat there working out the relationship between conveyor speed, pouring speed and other variables to put it into a PLC program so the wax poured into a candle in a glass filled the glass but did not touch outside of the glass, boolean logic is all part of the job now, very interesting, once you know it, frighting when the boss is saying "Your an electrician fix it." and you though kernel mapping was looking a woman up and down, even the description is frighting "The
kernel trick avoids the explicit
mapping that is needed to get linear learning algorithms to learn a nonlinear function or decision boundary. For all and in the input space" OK not so much with domestic, but imagery numbers for example is really easy for some people to get into their heads, others find it really hard, and the whole concept of power factor correction is based on imagery numbers. You can be lucky and work for 50 years and never need it, but the way things are going I would not want to lay money on that.
"A" level maths does not touch them, you need further "A" level maths to learn about them. Yet all part of the electricians formal training. I thought I was good at maths, when I came to do my degree I found out that was far from the case, maths for any engineer is complex, and there is a very fine line between the electrician and electrical engineer, there are still jobs where as an electrician you only need skill, no real knowledge of how things work, I worked as an installation electrician a few times, dressing the cables and not marking the glands were more important then knowing ohms law. How to bend conduit, and how to shape tray where major skills, I was not that good and spent 6 months putting earth rods in and measuring their resistance as they said I had Zero potential.
As to collage my son decided it would be good to learn the correct way, he had read all about using rollers to bend tray, and thought some day he would get on a job where they did it the correct way, I have only used them once, the results were impressive but the tooling is expensive, so it got to the big day, the teacher said you can get rollers to do this, but we have not got any so we bend it by cutting, at this point my son went mad and demanded his fees returned. And actually got them. Installation is anther world, not even allowed to use a moving spanner, never mind vice grips. And I remember coming across the hawk gland, they were gas tight and it needed skill not to damage the gas seal, my time in Harland and Wolff was a real eye opener. Think it was the last ship built there the Schiehallion.
