... and since unlike today in 1966 there was no internet so very likely houses up to 1970 still had no earth to the lights.
I've been trying very hard to understand that statement, but have so far failed! Could you put me out of my misery?
When the Amendment 3 came out even people who did not buy a copy myself included knew from forums and the like what new things had been added.
Back in 1966 only if one had an apprentice at college would you likely know of any recommended changes.
It was a case "I've been doing it that way for the last 30 years why should I change?" and it took quite some time for new regulations to be adopted. Even working for a county council for me to read the regulations I would be quizzed as to why I wanted to read them and certainly did not have my own copy. So often ones knowledge of the regulations was by word of mouth not first hand reading.
When in 1991 the Sixteenth edition came out and in 1992 it became BS 7671:1992 there was for the first time that I remember an exam to show you could read the book. It was around the same time that the JIB got a foot hold rather than the Unions and electricians mates passing a 16th Edition exam we accepted as electricians some thing which after I am sure they regretted but once accepted it would seem no one was de-graded.
Although today getting a JIB card is not easy it was not always that way. I was under the NAECI agreement rather than JIB so no card was issued it was always a data base system "Advanced Electrician" was awarded after so many years in the trade no exam required.
But even in 2000 going to the office to view the regulations was met with why do you want to know. When I bought my own copy of the regulations in order to take the C&G 2381 as it was then I found there was a host of errors in my thoughts as to what was required.
In the main I thought there were regulations saying I needed to earth metal window frames and cooker isolators had to be within 3 meters of cooker and sockets needed to be at least one meter from sink non of which actually existed. But also there were regulations that I did not know about but as the internet arrived the dark ages vanished and over the years we tend to forget how slow changes took place.
I am sure today if I bought a new Book 3 there would be many changes. For one it would seem for rented accommodation it will now be 5 years not 10 years between inspections and it seems likely the insurance requirements will also slowly slide south of the boarder so we are all singing from the same sheet.
But back to the point of the thread. Some DIY guy wants to fit metal switches rather than the existing plastic. OK my house I have from time to time tested the earth and to date there has never been a problem built in 1979 to swap a plastic to metal is unlikely to cause a problem.
My mothers house 1954 however is very different and some switches have been moved so there may be PVC wiring to lights but there is no earth even if there is an earth wire. My son had an ex-council house wired with 16mm conduit which to be fair was originally earthed but alterations had removed some of the conduit and again PVC cables may have had earth wires but they were not connected to anything.
So unless like me you have lived in the house from new an earth wire in a switch box means nothing. Often ceiling roses are replaced with choc blocks and shoved up the hole with just line and neutral connected to the class II lamp and all too often the earth is lost.
So from answers it would seem one one likes the idea of a DIY guy using a make shift meter. So what other method? With the main isolator on and the MCB off then we should get continuity between neutral and earth with TN systems but often no neutral at a light switch.
So what? Be it a door bell (battery) and two leads or a multi-meter on ohm range and measuring to a know good earth would work even if the power was totally isolated. My house again all metal back boxes so simply measuring from 3.5mm fixing screw to another 3.5mm fixing screw one can show there is an earth. But plastic back box and that fails.
So ideas simple idea some one wants to fit metal switches how can they be instructed to do the tests to see if these can be fitted? I will set limit to £75 for test equipment total so come on how to test DIY style?