I don't think it's the schools' responsibility Eric, it's the parents'.
Oh no not another I blame the parents? My son and I were working in BT buildings and every time a BT guy complained he would say "I blame the parents" he would never bother telling them his parent was also his boss.
However the parents can only teach the children if they have the knowledge to impart. The fact that in my family tracing back to 1800's there were all engineers and before that master mariners does not mean every family has the same back-ground. The whole idea of schools is parents don't always have the skill required.
I would personally like to see a return to being able to leave school early when taking up a trade. To have my fathers 7 year apprenticeship today would make tradesman 25 year old before they are qualified and by 20 years old people are looking at starting a family and buying a home so we are reducing apprenticeship training to an all time low. Leaving school at 16 when apprenticeship deeds are signed would go a long way to ensuring we retain our skill base.
But even when my children went to school they were shown how to fit a plug. I remember it well as before that event I had shown them how to fit a plug and to select the appropriate fuse and this did not line up with how taught at school and my children decided to tell the teacher he was wrong which did not go down well.
I did manage to teach the children how to hold their tongue, but even this did not work, when told there were two types of transistor and asked if anyone knew what they were, my son answered Bi-polar and Field effect sir. Only to be told no it's NPN and PNP at which he burst out laughing. I had to explain to the teacher that NPN and PNP was a sub-division of Bi-polar only to get the comment well field effect must be something new. He saw my smile and asked what was funny so I did tell him the field effect was found first.
But the point is who teaches the teacher? I returned to college only 5 years ago to take some "A" levels. The book for physics showed a fluorescent lamp wiring diagram without the ballast? The starter would without question blow and either the lamp would fail to start or if it did start there would be no current control so it seems even the books are getting it wrong. Have the "A" level people never heard of proof reading books?
] for the OPD to operate, but I presume you meant that it was too high for the magnetic part of an MCB to operate (i.e. so as to achieve, say, the 'disconnection times' required by BS7671). However, it is surely the case that the thermal part of an MCB (or a fuse) should operate before the cable comes to any harm (even if that takes some time), regardless of the loop impedance? If that were not the case, then such devices would be useless for 'overload' (as opposed to 'fault') protection, wouldn't they? After all, an OPD only "knows" what current is going through it, and for how long, and how that compares with what the cable can tolerate - it knows nothing about the impedances (or voltages) that are resulting in that current.
