Mains electrical safety - 1952 style!

[RojDW48]

This is the mains cable I extracted from the HMV2001 RP under discussion on the forum. L,N and E all a uniform brown. I have seen differentiation in the wire strand colours before - but not even that here!

Really good RP, though.

[mark_in_manc]

I've got a beige version of that on an HMV autochanger, and the same on an Anglepoise lamp. Does rather concentrate the mind when changing a plug

[Boater Sam]

My Korting tape recorder was wired with the same type of cable, original.

[Kentode]

Brown to brown, brown to brown, throw the switch and stand well back!

(Apologies to Tractionist but I couldn't resist)

[MrBungle]

Heathkit did this for a number of years. Except grey.

Interestingly one thing I had, adding “idiot builder to it”, the earth had broken in the plug end and wasn’t contacting anything. In the device end, the live had broken off and was touching the chassis. This appeared to be because they had stripped the ends with a kitchen knife or something and cut through most of the strands too. You were supposed to put the earth in the middle but alas it was incorrectly wired with earth on the outside too.

Snip! And IEC socket added.

[Michael Maurice]

One of my Kortings had the same, as long as you remember that the middle wire was earth you'd be ok.

[turretslug]

I've seen that type of flex on moulded IEC C5 leads that had moulded 3-pin US plugs at the other end, supplied with older laptops. At least if the wall plug is retained, it's not a problem (though many would doubtless have been cut off and rewired). I can't remember if one outer core was ribbed or not- I might just have the odd one in the loft cable bucket, I'll have a look sometime. If so, that's at least an easy positive (!) confirmation on all 3 cores- though, as mentioned, common sense doesn't always apply.

[emeritus]

My Anglepoise lamp, bought new in 1968, has that type of flex in black, wired with the earth on one of the outside cores. I suppose that type of mains flex was withdrawn when the electrical regulations changed in the early 1970's.

[sexton_mallard]

I have a lead like this on a HMV 1508 portable radiogram in the roundtoit queue. There is an 'E' on the centre of the appliance end plug (pictured).

[G6Tanuki]

Why's it an issue? wire it with the centre-core as earth, it'll be just fine.

In most of the world mains-plugs are non polarised so freely interchanging 'live' and 'neutral' is not a problem.

[AC/HL]

It isn't to us, and other technically minded people, but given the mess that some people make of three clearly marked wires, the results of trying to guess which is which could be interesting to say the least. Perhaps this was an early implementation of a moulded on plug.

[RojDW48]

Originally Posted by G6Tanuki

Why's it an issue? wire it with the centre-core as earth, it'll be just fine.

I would have thought the issue was quite obvious. People wire their own plugs and, as members have reported, get it wrong. It's all very well having a convention of 'middle = earth' but some people, unaware of that, are going to think 'they are all the same so it doesn't matter'. You might think that those people should not be allowed to breed (and, indeed, an element of natural selection might take place!) but, in the end, a bit of rudimentary colour coding is surely a good thing.

[MrBungle]

Indeed.

When I was at school, the librarian gave herself a very nasty shock. She was wiring a plug on a television which had come in (big Thorn thing on a stand and wheels) and refused to take a 13 year old's advice that it was being done wrongly. She just stuffed the wires in anywhere, turned it on. Nothing. Gave the aerial cable a wiggle and found out that the chassis was earthed to live. Fortunately no damage other than a quick lesson.

That was with colour coded wire.

It has got to the stage where I bought a power supply the other day, a little switch mode supply, which came with instructions saying not to eat the power supply. I have wondered every day what situation lead to that warning being added.

[turretslug]

Deterring M. Mangetout? The dopey librarian tale is all too redolent of my and no doubt many others' schooldays- "Know your place and don't dare question your elders and betters- even when they're conspicuously wrong!" Yuk.

I'll admit to scoffing a little when I found that it was mandatory for appliances to have fitted plugs, and no doubt others muttered about Darwinism- but having found so many instances of incompetent fitting of plugs where the innocent could come to grief, it's likely to have been a very good thing. I also recall Anglepoise lamps and my parent's electric blanket with uncoded flat-triple flex and thinking that it was neat and easily tucked away- but that itself is regarded as a wear hazard.

[Rubberfingers]

When the appliance was bought new, the earth core may well have had a sleeve on it, either with an "E" or coloured green, of course over the years, the sleeve may well have been lost during plug changes, or plugs being cut off, etc. Anyone got the manufacturers instructions for anything sold with this type of flex, what does it say in regards to plug wiring?

[MrBungle]

I'd forgotten about Mr Lotito, a subject of awe and amazement to a teenager at the time. Now I think he was a wally.

I would say that I am a fan of fitted plugs but it appears that some of them are just as terrible as them not being fitted. In the last few years I've seen ones with so little plastic that you can't get hold of them, clearly because it saves a few pence. Then there are the ones with a partially plastic earth pin (why?!?!?). And on top of that I've had a couple where a pin has been left in the socket.

Ergo I'd rather snip them off and stick a nice quality MK urea formaldehyde plug on. Problem is, those are rather expensive.

[Nickthedentist]

In the last few years I've seen ones with so little plastic that you can't get hold of them, clearly because it saves a few pence. Then there are the ones with a partially plastic earth pin (why?!?!?). And on top of that I've had a couple where a pin has been left in the socket.

All dubious imports and with fake approvals, no doubt. In general, proper moulded-on plugs are excellent. A really well-fitted rewireable plug is a rare thing from what I've seen, even in "the good old days".

[TonyDuell]

Personally I loathe moulded mains plugs, to the extent that I generally cut them off and replace them with a properly-wired (MK) plug. The problems with moulded plugs that I have experienced includes them running hot with the normal load (i.e. on the appliance as supplied), no earth connection (3 core cable, 3 pin plug, but the earth was not connected!), minimal strain relief (I've had the outer jacket pull out of the plug on many such cables), etc.

Getting back to the original cable, I am sure I've seen such 3-core zip wire where the middle core was double insulated, inner insulation being green. That was clearly the earth wire, and for a lot of things the live and neutral can be swapped without problems.

[Boater Sam]

The correct and tidy fitting of a 13A plug. As an art form, discuss.
Its what separates those that really can do and those that know exactly how to do everything but never have.
i.e. the practical and the over educated.
I know which group I want to be with when all the technology fails and we go back to the dark ages.

[emeritus]

Just removed the cover of the mains plug of my Anglepoise, and the outer Earth conductor does indeed have a rubber sleeve marked "EARTH".