Re: Mains plug restoration
 

One thing is for sure- we can no longer rely (if we ever could) on moulded-on plugs being 'safe' or better than conventional plugs. Having said that, i always regard conventional plugs as requiring checking/maintenance rather than fit and forget. It's part of my regime to check rubberised duraplugs for blackening of the pins!
Dave

Re: Mains plug restoration
 

I would urge people to refer specifically to the quote of the ACOP in Post #39 as this is the primary source of information on how to deal with existing plugs and appliances, which is what we are mainly concerned with here. The Plugs and Sockets etc. (Safety) Regulations 1994 and BS1363-1:2016+A1:2018 are the applicable documents regarding products newly manufactured or placed on the market.

BS7671 is chiefly about electrical installations of buildings rather than portable appliances. It refers to the use of plugs mainly to describe the requirements they pose for the use of sockets. Some parts are worded in slghtly ambiguous ways; for example the reference in post #32 to one pin being engaged while another is fully exposed, is basically a prohibition on any kind of socket where pins of a plug could be engaged individually, e.g with the neutral pin in the line socket and the line pin overhanging the side of the socket body.

Regarding the replacement of ISOD-equipped plugs on class II equipment, the ISOD is one option available to manufacturers but there is no requirement for a plug fitted to class II equipment to use one. I.e. there is no 'Class II plug.' There has been much debate on whether changing an original moulded plug to a re-wireable one constitutes a modification of the equipment. To an extent this is up to the manufacturers. On another forum, we ran an experiment in which various appliance manufacturers' technical departments were asked whether it was acceptable to replace their plug with an alternative within the prescribed methods of installation and use set out in their instructions. Answers included Yes, No, and incomprehensible waffle indicating that the question was not understood. The main purpose in that case was to prove that the warranty was not being invalidated by removing the original plug.

There have been documented cases of substandard moulded plugs and cordsets, for sure. However, from practical experience, I would estimate the number of defective installations of rewireable plugs compared to (compliant, approved) moulded ones as found in the field to be around 100:1. Therefore I would contend that in the real world, moulded plug installations (as opposed to the plugs themselves) are signifcantly safer than rewireable ones.

Re: Mains plug restoration
 

The pin insulation is the least of our worries because until about a year or so ago there were 4-way power strips on sale from vast baskets at the end of the isles in one of the big DIY chains with shutters that can be opened without tools.
They were on sale for several years too.

Re: Mains plug restoration
 

I use Brasso on the pins and take them apart, put separate parts in a sink full of hot soapy water.

Tom

Re: Mains plug restoration
 

I am afraid this is very common, and while it seems to be at variants with the spirit of the regulations, I think either it doesn't apply to non fixed accessories, or a blind eye is being turned somewhere.

In this example the 6 way strip is badged "Belkin" and the block adapter is a Masterplug
Attachment 238826
These were two that were immediately to hand, but I'm could have dug out more.

Re: Mains plug restoration
 

They are useful if you want to stick your meter probes in to test the voltage.

Re: Mains plug restoration
 

I thought that was what IEC C13 leads were for ;D.

Cheers,

GJ

Re: Mains plug restoration
 

For probes with thicker insulation on them;D

Re: Mains plug restoration
 

That reminds me of the extremely useful and quite safe method of access for testing mains voltage afforded by a socket-opening gadget included in an electrical testing set made by Plasplug some years ago. Photos attached.

Cheers
Chris

Re: Mains plug restoration
 

Thinking of shutters, I recall a particular style of mains-outlet a couple of decades back where the shuttering on the L and N sockets was by way of a sort-of nylon butterfly-device that pivoted on a spindle centred between the 2 sockets; there were small ramps moulded on the parts of the butterfly visible through the socket-holes and arranged that when you put a plug in the butterfly rotated on its spindle to allow the pins further inward access.

There was no involvement of the earth-pin in the shutter-opening.

Anyone else recall these sockets? I thought it was a rather cunning design, and would have made it a lot easier to develop an 'updated' lightweight version of the 13A plug with only two pins for use with the current profusion of double-insulated low-power devices where the need for an earth-pin to open the shutters just adds bulk and cost.

Re: Mains plug restoration
 

Yes, weren't they MK sockets? You could tell when you had one because the shutters were not flat, but kind of wedge shaped, and L/N were different so it would do as you describe.

Re: Mains plug restoration
 

They were made by MK and the science labs at the school I went to from 1976 to 1981 had them, so they've been around for a long time.

Re: Mains plug restoration
 

I wonder whether that was originally inspired by those ghastly "safety" devices that plug into a socket, replacing a perfectly functional approved safety system with one with no approvals whatsoever. :wall:

Re: Mains plug restoration
 

Wasn't that one of the MK sockets? I seem to remember the shutter had to be pushed in before it could turn, therefore you had to have both the live and neutral pins going in together. So just sticking something in one of the holes wouldn't do it (if it did it woulrather defeat the purpose of the shutter.

Re: Mains plug restoration
 

The later rotary shutter MK sockets had two dimples in the wedge shaped part of the shutter to stop two pin plugs from across the channel from being inserted.
With earth pin operated shutters you had to sort of "walk" the plug in.

Re: Mains plug restoration
 

I noticed that when I had my eye test earlier this week, the optician's premises had all the sockets stuffed with those things.

EDIT: but it does take me back to my own childhood. My Dad bought a Hanimex cassette recorder. It came with a 2 pin continental plug. I remember him using a screwdriver to push into the earth hole to open the shutters to push in the 2 pin plug, but also him going mad at me (as a five year old) for doing the same thing. To be honest, I really don't know why he didn't simply cut off the 2 pin plug and replace it with a BS 3 pin, which I finally did a few years later. I reckon I still have that cassette recorder in the garage though I suspect the mains lead is long vanished.

Re: Mains plug restoration
 

I have examples of both types of rotary shuttered MK sockets in my kitchen. The original MK patent for the rotary shutter covered both 2 pin and 3 pin sockets. They filed a later one covering the dimples that prevent a europlug being used with a 13A socket. Both patents expired more than 20 years ago so anyone can make these types of shuttered socket now.

Re: Mains plug restoration
 

Yes, I even made a Youtube video two years ago.
https://youtu.be/JSLuhwfDeXE

Re: Mains plug restoration
 

Looks like a Malaysian plug key. See 24 and 25 here:
http://www.plugsocketmuseum.nl/British1.html

Every Malaysian brings a pocket-full back after their first annual trip home. They cost around 15p out there.

Re: Mains plug restoration
 

I wonder whether this sleeving of pins is another matter of safety gone mad. I grew up in a house with BS546 15amp plugs and never once got my fingers across the pins while plugging in.
I did experience, only once, what happens if you put your fingers into a bayonet light socket however.