UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Other Vintage Household Electrical or Electromechanical Items

Notices

Other Vintage Household Electrical or Electromechanical Items For discussions about other vintage (over 25 years old) electrical and electromechanical household items. See the sticky thread for details.

Closed Thread
 
Thread Tools
Old 6th Aug 2021, 6:22 pm   #61
rambo1152
Dekatron
 
rambo1152's Avatar
 
Join Date: May 2010
Location: Manchester, UK.
Posts: 3,023
Default Re: Mains plug restoration

Quote:
Originally Posted by winston_1 View Post
I wonder whether this sleeving of pins is another matter of safety gone mad.
No. It was a very sensible, and fully "backwards compatible" enhancement to the standard.
__________________
--
Graham.
G3ZVT
rambo1152 is offline  
Old 6th Aug 2021, 6:43 pm   #62
GrimJosef
Dekatron
 
Join Date: Sep 2007
Location: Oxfordshire, UK.
Posts: 3,725
Default Re: Mains plug restoration

Backwards compatible maybe, but it must have added to the fabrication cost, and it also thins down the brass in the pin over the insulated length. This must make it more fragile. In principle it will make it a bit more resistive too, and therefore more prone to heating, but I suspect that that's negligible compared with other, thinner, elements in the current path inside the plug and the socket.

However if it saves a lot of injuries and deaths then it's obviously worthwhile. If it saves none then it isn't. I wonder if anyone knows whether it does ?

Cheers,

GJ
__________________
http://www.ampregen.com
GrimJosef is offline  
Old 6th Aug 2021, 6:58 pm   #63
winston_1
Hexode
 
Join Date: Oct 2012
Location: London, UK.
Posts: 384
Default Re: Mains plug restoration

Doubt if many lives are saved. 240v across a finger won't kill, it will just be very uncomfortable.

They did this exercise in Australia with their thin pins and found the pins tended to break off and remain in the sockets. How safe is that? Not sure if they have fixed that problem.
winston_1 is offline  
Old 6th Aug 2021, 7:26 pm   #64
rambo1152
Dekatron
 
rambo1152's Avatar
 
Join Date: May 2010
Location: Manchester, UK.
Posts: 3,023
Default Re: Mains plug restoration

Quote:
Originally Posted by GrimJosef View Post
Backwards compatible maybe, but it must have added to the fabrication cost, and it also thins down the brass in the pin over the insulated length. This must make it more fragile. In principle it will make it a bit more resistive too, and therefore more prone to heating, but I suspect that that's negligible compared with other, thinner, elements in the current path inside the plug and the socket.

However if it saves a lot of injuries and deaths then it's obviously worthwhile. If it saves none then it isn't. I wonder if anyone knows whether it does ?

Cheers,

GJ
One thing the MK style shutter and and sleeved pin plug achieved, both separately and particularly when used together, was to put an end to the practice of trapping a pair of wires behind the plug to obtain a temporary supply. Actually it's still possible, but it's very difficult.

I did this countless times in customers houses to connect my soldering iron.
__________________
--
Graham.
G3ZVT
rambo1152 is offline  
Old 6th Aug 2021, 8:59 pm   #65
Red to black
Nonode
 
Red to black's Avatar
 
Join Date: Mar 2010
Location: Sunderland, Tyne and Wear, UK.
Posts: 2,263
Default Re: Mains plug restoration

Quote:
Originally Posted by Lucien Nunes View Post
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.
Lucien I have said it before on here, that you have people with a limited subset of knowledge that are trying to apply one set of standards (that they very well be familiar with) trying to apply that knowledge to another set of standards that they are not familiar with.

Yes there is a large degree of overlap between the rules, and yes the laws of physics still apply, however the different standards each have their own rules and caveats, and not many people know with any depth of certainty any of the rules that apply to maybe two standards if they are lucky! This is where problems arise, urban myths start to spring up and mistakes start to be made.
People whom are otherwise intelligent (and even experts in their own field) start to stray into unfamiliar territory and make big mistakes in the belief they are correct.
This is not a dig at anyone in particular btw.
__________________
I don't suffer from Insanity. I enjoy every minute of it.
Red to black is offline  
Old 6th Aug 2021, 9:08 pm   #66
Brigham
Octode
 
Join Date: Mar 2006
Location: Co. Durham, UK.
Posts: 1,039
Default Re: Mains plug restoration

Sleeved pins are a good idea. They make an unlikely electric-shock scenario even more unlikely.
Pretending that unsleeved pins are suddenly somehow 'lethal' is not such a good idea.
THAT is 'safety gone mad'.
Brigham is offline  
Old 6th Aug 2021, 9:27 pm   #67
GrimJosef
Dekatron
 
Join Date: Sep 2007
Location: Oxfordshire, UK.
Posts: 3,725
Default Re: Mains plug restoration

Quote:
Originally Posted by rambo1152 View Post
... the practice of trapping a pair of wires behind the plug to obtain a temporary supply. Actually it's still possible, but it's very difficult.

I did this countless times in customers houses to connect my soldering iron.
I did it once at CERN. I'd turned up for a meeting there having forgotten my BS1363-to-Swiss mains adaptor and needing to use my laptop, which had a flat battery. We couldn't find a lead with the right plug at one end and socket at the other to run into my power block. So I took the (removable) plug off my lead and wedged the (long, thin) bare wires into a 220V outlet. The Swiss/French/German engineers looked on with a mixture of amusement and horror . They didn't need telling not to put their fingers into it.

Cheers,

GJ
__________________
http://www.ampregen.com
GrimJosef is offline  
Old 7th Aug 2021, 12:44 pm   #68
Lancs Lad
Heptode
 
Lancs Lad's Avatar
 
Join Date: Oct 2018
Location: Blackburn, Lancashire, UK.
Posts: 582
Default Re: Mains plug restoration

Interestingly, the modern MK cooker control unit in my kitchen (pic 1 - installed new last year) has those rotary shutters.

The previous larger CCU (pic 2 - installed new in 1980) had earth pin operated shutters, while all the other MK wall sockets in the house had the rotary ones.

I very much prefer the new understated white switches to the red ones of the previous CCU - although they're still the same size.
Attached Thumbnails
Click image for larger version

Name:	wp_ss_20210807_0001 (2).png
Views:	66
Size:	192.7 KB
ID:	238951   Click image for larger version

Name:	wp_ss_20210807_0002 (3).png
Views:	67
Size:	139.9 KB
ID:	238952  
__________________
Best Regards,

Peter.
Lancs Lad is offline  
Old 7th Aug 2021, 9:33 pm   #69
Richard_FM
Octode
 
Richard_FM's Avatar
 
Join Date: Sep 2017
Location: Stockport, Cheshire, UK.
Posts: 1,630
Default Re: Mains plug restoration

Quote:
Originally Posted by Lancs Lad View Post
Interestingly, the modern MK cooker control unit in my kitchen (pic 1 - installed new last year) has those rotary shutters.

The previous larger CCU (pic 2 - installed new in 1980) had earth pin operated shutters, while all the other MK wall sockets in the house had the rotary ones.

I very much prefer the new understated white switches to the red ones of the previous CCU - although they're still the same size.
Until 2007 my parents house had a larger version of the right hand cooker switch. I've seen a version with neon indicators for the switches.

The socket was rarely used, possibly only when my Mum needed to use a hand mixer for something being heated in a pan.
__________________
Hello IT: Have you Tried Turning It Off & On Again?
Richard_FM is offline  
Old 7th Aug 2021, 11:17 pm   #70
emeritus
Dekatron
 
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 4,519
Default Re: Mains plug restoration

Shortly after the sleeved plug requirement came in, I ordered some stuff from one of the advertisers in one of the hobby magazines (Practical Wireless or Television), and included a couple of 13A plugs in my order. Well they did have sleeves, but the sleeving consisted of rather thin-walled plastic tubing that had evidently been pushed (or shrunk) over the pins of Hong Kong-manufactured unsleeved plugs, as the metal of the pins was of uniform cross-section over their entire lengths. The sleeving soon split and broke off, but as the plugs were cheap it wasn't worth complaining. I just bought some proper UK-made ones from a local high street shop.

When my son modernised his kitchen some 5 years ago, I replaced the original bulky (and not properly recessed) cooker point and 13A socket with a compact MK one (with neons), the size of a conventional double socket. I was disappointed by the quality: the neons didn't line up with their transparent red windows, there was complete absence of any means for positively keeping them in position, and the act of pushing on their leads to position them, made the red windows ping out: the windows were simply snapped into position and were only retained by ridiculously-small detents. A bit over-value-engineered methinks.

Last edited by emeritus; 7th Aug 2021 at 11:24 pm. Reason: typos
emeritus is offline  
Old 8th Aug 2021, 6:57 am   #71
G.Castle
Pentode
 
Join Date: Dec 2020
Location: Swaffham, Norfolk, UK.
Posts: 105
Default Re: Mains plug restoration

Quote:
Originally Posted by winston_1 View Post
Doubt if many lives are saved. 240v across a finger won't kill, it will just be very uncomfortable.
240 across the fingers would make it very difficult to let go of the plug.

What happens when your other hand or another body part is touching an earthed conductor?

I have first hand experience of this, in my first job I was using a 240v scroll saw, the plug was the older type, socket not switched, system, (customers), not protected by an RCD.

I wasn't killed, obviously, but did sustain a dislocated shoulder.

Many pundits have said since what should have been done regards the work equipment, environment etc. But all it needed to prevent the accident was a fifty pence shrouded pin plug.

I didn't put two fingers round the plug body onto the pins, my little finger on my right hand touched the live pin and my other hand was flat on an earthed stainless worktop.

Very few people are ever electrocuted, but a lot die from secondary impact, falling from a ladder for instance, that is the real danger of electric shocks.

So what the question is, is what number of avoidable injury's or deaths are acceptable, not if this kind of regulation actually saves lives: these sorts of rules are made for better or worse as a reaction to a problem, the unshrouded pins of old 13A mains plugs were obviously causing significant footfall at hospital AE departments for the regs on plug top designs to be ammended.

A lot has been written about the safety of vintage equipment, an old valve radio that is properly maintained for instance, is safe because the user is protected from casual contact of live parts, it is not the case with these unshrouded plugs.

Display them as curios, or bin them.
G.Castle is offline  
Old 8th Aug 2021, 10:41 am   #72
Herald1360
Dekatron
 
Herald1360's Avatar
 
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 15,757
Default Re: Mains plug restoration

Quote:
Originally Posted by Red to black View Post

.......

People whom are otherwise intelligent (and even experts in their own field) start to stray into unfamiliar territory and make big mistakes in the belief they are correct.

......

Just so
__________________
....__________
....|____||__|__\_____
.=.| _---\__|__|_---_|.
.........O..Chris....O
Herald1360 is offline  
Old 8th Aug 2021, 11:33 am   #73
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 22,615
Default Re: Mains plug restoration

There is a story that shrouded pins were introduced primarily to stop children and malicious individuals from using a coin to short out the pins, which is otherwise very easy to do with a BS1363 plug. Switching the socket on would produce an impressive bang and shut down the ring main.
paulsherwin is offline  
Old 11th Aug 2021, 6:46 am   #74
G.Castle
Pentode
 
Join Date: Dec 2020
Location: Swaffham, Norfolk, UK.
Posts: 105
Default Re: Mains plug restoration

Quote:
Originally Posted by paulsherwin View Post
There is a story that shrouded pins were introduced primarily to stop children and malicious individuals from using a coin to short out the pins, which is otherwise very easy to do with a BS1363 plug. Switching the socket on would produce an impressive bang and shut down the ring main.
That may have indeed happened, but the cynic in me would expect something like that to be cited as a reason for changing the regulations, in preference to inviting litigation in acknowledgment that the design was, (to the young and careless user at least!), dangerously flawed.
G.Castle is offline  
Old 11th Aug 2021, 1:41 pm   #75
rambo1152
Dekatron
 
rambo1152's Avatar
 
Join Date: May 2010
Location: Manchester, UK.
Posts: 3,023
Default Re: Mains plug restoration

A 1p piece under a BC lamp does much the same thing, so they should have banned BC lamp holders and lamps in favour of those foreign ES items.

Oh wait, they didn't need to ban them, they are slowly disappearing anyway, through attrition / commercial forces.
__________________
--
Graham.
G3ZVT
rambo1152 is offline  
Old 11th Aug 2021, 2:27 pm   #76
Dave Moll
Dekatron
 
Dave Moll's Avatar
 
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 5,452
Default Re: Mains plug restoration

But of course ES bulbs introduce their own problems, given that the metal collar is connected to one side of the mains, so it's vital that the socket is wired with this side connected to neutral.
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley)
Dave Moll is offline  
Old 11th Aug 2021, 3:29 pm   #77
Chrispy57
Pentode
 
Join Date: Mar 2020
Location: Rochdale, Greater Manchester, UK.
Posts: 129
Default Re: Mains plug restoration

I wonder if, like me, Paul and Rambo were unfortunate enough to read "Calling Base 10" by Douglas Castle, (1943) in the Blackie's books for boys and girls series at junior school, in which the juvenile hero does indeed employ the coin in the light fitting trick to evade his Nazi captors?

Also, thanks to Winston for the info on the Malaysian plug key and link to that comprehensive document - very informative. At least the Plasplugs tester version has the text "remove after testing" and identifies L and N correctly!

Cheers
Chris
Chrispy57 is offline  
Old 13th Aug 2021, 6:12 pm   #78
YoungManGW
Hexode
 
YoungManGW's Avatar
 
Join Date: Dec 2011
Location: Oswestry, Shropshire, UK.
Posts: 384
Default Re: Mains plug restoration

My mother still has the butter knife, with two chunks missing from the blade, with which, back in the early 1970s, my younger brother, then a toddler, removed a plug from a socket. Shrouded pins are probably a good idea.
Regards,
Richard
__________________
Blog: www.ymgw.blogspot.com
YoungManGW is offline  
Old 13th Aug 2021, 9:29 pm   #79
Glowing Bits!
Octode
 
Glowing Bits!'s Avatar
 
Join Date: Oct 2011
Location: Wrexham, North Wales, UK.
Posts: 1,277
Default Re: Mains plug restoration

Quote:
Originally Posted by Dave Moll View Post
But of course ES bulbs introduce their own problems, given that the metal collar is connected to one side of the mains, so it's vital that the socket is wired with this side connected to neutral.
Which is damn near impossible given how European lamp plugs can go both ways in a Shuko socket.
__________________
Rick, the annoying object roaming the forum.
Glowing Bits! is offline  
Old 13th Aug 2021, 10:53 pm   #80
emeritus
Dekatron
 
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 4,519
Default Re: Mains plug restoration

I think it was mentioned on another thread some time ago that the current UK regs do not require the threaded part of ES sockets to be connected to N.
emeritus is offline  
Closed Thread

Thread Tools



All times are GMT. The time now is 4:17 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Copyright ©2002 - 2021, Paul Stenning.