johnlinford Posted April 30, 2008 Share Posted April 30, 2008 Fair cop, while refining my point I removed the bit that pointed out that you are of course supervised... My point still stands that there's a big difference between being told how to do something and actually doing it, supervised or not. Link to comment Share on other sites More sharing options...
bluetobits Posted April 30, 2008 Share Posted April 30, 2008 Not strictly, true, Yes the visual inspection would show if the plug has been wired correctly, however........ But how do you know the piece of kit / lead is ok? Sorry - I didn't make it clear.I mean as far as testing the job of wiring said plug to a single cable. It should go without saying that if it's connected to a piece of kit (unlikely in the case of an educational establishment's training session) then yes a full test is essential. But that's not what I meant. Every electrical job should be tested - no matter how small. You can't see internal insulation breakdown, excessive contact resistance. Even simple things you can see can be missed. Polarity errors for example are not uncommon. The eye and brain is easily fooled. How many times has a competent spark in an absent minded moment fitted a duraplug and forgotten to fit the plug top over the cable end before wiring the plug? Link to comment Share on other sites More sharing options...
Ynot Posted April 30, 2008 Share Posted April 30, 2008 Every electrical job should be tested - no matter how small. You can't see internal insulation breakdown, excessive contact resistance. Even simple things you can see can be missed. Polarity errors for example are not uncommon. The eye and brain is easily fooled. How many times has a competent spark in an absent minded moment fitted a duraplug and forgotten to fit the plug top over the cable end before wiring the plug?Ah, but that can depend on whether the job is intended for actual use connected to the supply. If, as an educational exercise, plugs are fitted by students, then a visual check by the instructor/tutor should be more than sufficient to warrant a pass/fail etc. Link to comment Share on other sites More sharing options...
Ike Posted April 30, 2008 Share Posted April 30, 2008 Every electrical job should be tested - no matter how small. You can't see internal insulation breakdown, excessive contact resistance. Even simple things you can see can be missed. Polarity errors for example are not uncommon. The eye and brain is easily fooled. How many times has a competent spark in an absent minded moment fitted a duraplug and forgotten to fit the plug top over the cable end before wiring the plug?I couldn't disagree more. We're taking about young people wiring plugs (possibly for the first time) and in my opinion we should be making things as simple as possible. Plugging the plug and lead into a portable appliance tester that spits out a couple of numbers really doesn't help matters. If you can't spot a polarity error in a 13A plug then I'm sorry but you shouldn't be wiring plugs never mind supervising others. How would you spot a polarity reversal on a bit of kit for example? In the real world there are going to be times when a portable appliance tester simply isn't available, heck you might even be replacing the plug on the portable appliance tester. Teaching others to depend on one to check their work is in my opinion nothing less than irresponsible. Any reasonably competent person will be able to spot far more marginal terminations that a portable appliance earth bond test would pick up. Sure use a portable appliance tester to check insulation if you have reason to suspect it (old cable, excessive heat or moisture exposure etc.) or the earth bond if you can't inspect all the connections but for a plug fitted to a bit of flex it won't pick up anything a competent person wouldn't in a visual inspection. Link to comment Share on other sites More sharing options...
Andrew Edwards Posted April 30, 2008 Share Posted April 30, 2008 I can't remember when I was shown how to wire a plug. It must have been my dad. Just glancing around the room I am in. I am surrounded by various electrical appliances and they all have moulded rubber plugs and they are all detachable from the device. This suggests to me that the 'powers that be' are trying to discourage the changing of plugs in favour of a complete power cable replacement in the event of anything other than a blown fuse. Of course this does not stop people from cutting the plug off, stripping back and fixing a new one. But then surely if you have enough nouse to think of that then you know how to wire it anyway. Even if they were not entirely sure, all new plugs usually have a wiring diagram somewhere on the plug or in the packaging. I would have to say that I have not changed a plug at home for many many many years. Infact the only thing I can think of that does not have a moulded rubber plug are my ceramic bedside lamps which are more likely to be smashed themselves rather than the plug. Now then, the OP was regarding kids coming to do work experience. A practice specifically designed to begin to teach new skills not necessarily covered by academic subjects. Even if wiring a plug was on the compulsory curriculum, there is an ever increasing chance that this skill will be never used in normal home life. Link to comment Share on other sites More sharing options...
berry120 Posted April 30, 2008 Share Posted April 30, 2008 Every electrical job should be tested - no matter how small. You can't see internal insulation breakdown, excessive contact resistance. Even simple things you can see can be missed. Polarity errors for example are not uncommon. The eye and brain is easily fooled. How many times has a competent spark in an absent minded moment fitted a duraplug and forgotten to fit the plug top over the cable end before wiring the plug? If a student's learning how to wire a plug, to me that's way overkill. To start with, the plug's probably going to be ripped off again for the next student to have a go, so it's not going to be a permanent thing by any means. Secondly, if you're provided with good equipment then for a simple wiring a plug job there's not a lot (if anything?) a PAT test will pick up you won't pick up visually. Yes, if you're doing a bigger job or for checking things are safe it's important, but I'd dispute your use of the word "every". As for polarity errors not being uncommon... I don't think I've ever seen someone that's competent wire up a plug with the polarity all muddled up, you surely shouldn't be THAT easily fooled if you're teaching others. Yeah I've seen people occasionally miss the cable grip off by mistake, seen they've left it on the desk and had to open the plug up to put it back in. But that's the sort of reason why a visual check's more important, because a PAT test isn't gonna pick that up! Link to comment Share on other sites More sharing options...
J Pearce Posted April 30, 2008 Share Posted April 30, 2008 On the polarity field I had a funny today. Wired a cable, looked all good. Had a polarity invert. After much scratching of heads we realised the 16A ceeform itself was labelled wrong... Pics and full story coming to TWIBM very soon. Link to comment Share on other sites More sharing options...
matt c Posted April 30, 2008 Share Posted April 30, 2008 *Matt C waits patiently to see if his dad was any good at teaching and wiring plugs... When can we expect the results of the gradings, I wonder? And on the subject of the incorrectly labelled ceeform, I had that one too with a 63A TPNE at work. We were testing a triplex 5.5kW vacuum plant (on some nice new leads) and when we plugged it all in and switched it on, it didn't suck, but made an expensive sounding grating/clunking noise. Luckily, everything was OK mechanically, and after some headscratching and some multimeter jiggerypokery, everything was fine. Had two of the phases swapped, and the vacuum pumps were running backwards... Matt Link to comment Share on other sites More sharing options...
Ynot Posted April 30, 2008 Share Posted April 30, 2008 *Matt C waits patiently to see if his dad was any good at teaching and wiring plugs... When can we expect the results of the gradings, I wonder?Well, as has already been pointed out, no less than 99 people have stated that they have no problem wiring a plug, but only SIX thus far have deigned to actually take up the challenge. Before the 'results' are published I was hoping for a much larger take up of 'money where the mouth is' from the youngsters this was aimed at!! Could it be a case of too many teens being too cocky with a simple answer yet not confident enough to post me the evidence...?? I wonder... ;) Link to comment Share on other sites More sharing options...
berry120 Posted April 30, 2008 Share Posted April 30, 2008 Missed it the first time! (Have PMed you) Actually really interested as to what I might be doing wrong over this! Link to comment Share on other sites More sharing options...
LampTramp Posted April 30, 2008 Share Posted April 30, 2008 Every electrical job should be tested - no matter how small. You can\'t see internal insulation breakdown, excessive contact resistance. Even simple things you can see can be missed. Polarity errors for example are not uncommon. The eye and brain is easily fooled. How many times has a competent spark in an absent minded moment fitted a duraplug and forgotten to fit the plug top over the cable end before wiring the plug? Well the last time I put a plug on....there s not a plug top issue (as years gone by...!) mabe you have some OLD 20th CENTRY STOCK!!!!! Moderation: Excessive quoting removed. Link to comment Share on other sites More sharing options...
Ynot Posted April 30, 2008 Share Posted April 30, 2008 Now up to 8 entries.Come on chaps - still plenty of claims to substantiate...:) Link to comment Share on other sites More sharing options...
berry120 Posted May 1, 2008 Share Posted May 1, 2008 Now up to 8 entries.Come on chaps - still plenty of claims to substantiate... :) How many / long are you waiting for? ;) Link to comment Share on other sites More sharing options...
Andrew C Posted May 1, 2008 Share Posted May 1, 2008 As for polarity errors not being uncommon... I don't think I've ever seen someone that's competent wire up a plug with the polarity all muddled up,I have*, but far more common is a trailing socket screwed up. So, I agree in the context of this thread that just a visual of the plug is OK, but PAT really does help in the real world! *I've also seen him visual a trailing socket, only to drop it with a ******** when he discovered that the other end was still attached to the wall. I encourage everyone I work with to adopt a "Test the plug FIRST" routine to avoid this scenario, and to ensure both are checked. Link to comment Share on other sites More sharing options...
smalljoshua Posted May 3, 2008 Share Posted May 3, 2008 Now up to 8 entries.Come on chaps - still plenty of claims to substantiate...:DAny chance of releasing the resultw Via PM for those that have already entered? Also How many are you waiting for? Josh Link to comment Share on other sites More sharing options...
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