ECN Forum
Posted By: Trumpy In the name of safety - 11/18/09 08:34 PM
Has anyone from the "Down-Under" area noticed that the newer single phase 10A plugs have a tendency for the phase or neutral pins to break prematurely, as of late?

Here's a picture of the 2-pin version of these plugs:

[Linked Image from electrical-photos.com]

Those from overseas will note that the pins have a layer of plastic on the pins, where they exit the plug body.

Now this layer of plastic isn't thin, but the issue is, allowance for this plastic is at the expense of pin material all the way around the pin.

In this last week, I've replaced 6 of these plugs for various people, where one of the pins has snapped.
It also raises a safety question of "What is the mechanical/electrical integrity of one of these plugs like where the pin(s) might be bent in use, but hasn't broken yet?".
The pins on the older version of the plug, were quite hard to bend, these ones are quite soft.

Bear in mind that these are the only version of the plug you can buy now, manufacturers are required to conform to the regulations.

I also have a problem with this plug (in it's current guise) having a specification of 10 Amperes, with the reduced cross-sectional area on the pins.

This idea came about a couple of years back, the concept being that if a child removes a plug from a socket-outlet, there will be a wide enough gap between the socket face and the plug-top front, for a child to be able to get thier fingers in that gap, causing either burns or electric shock or both.

One other work-around would be recessed socket-outlets, these are on the market here, but you need a good stiff drink before reading the unit price of them. eek

Your thoughts?



Posted By: aussie240 Re: In the name of safety - 11/19/09 12:41 AM
I suspect the insulated pins were introduced because the recessed sockets were a flop when they tried to introduce them, given the amount of plugs, double adaptors and plugpack transformers that wouldn't fit into them.
It's not just the flimsy pins on the plugs now, but the flex attached to most 2.4KW appliances in recent years is underrated and becomes too warm for my liking. Proper 1.5mm flex and a chunky old stock bakelite plug fixes the problem.
As for the new plugs I usually end up bending the pins just pushing the covers on they're so weak. Anyone from this part of world will know of the force required to push the cover over the part with the pins and terminals when connecting a plug.
The story I heard re the introduction was that someone with a chain around their neck leaned over a GPO and it went in the gap touching the live pin. Apparently this person was some big knob somewhere who had the necessary influential powers to get things changed. Could be an urban myth of course.


Posted By: Trumpy Re: In the name of safety - 11/19/09 01:06 AM
Thanks for that aussie. wink

Yeah, I bought up a heap of the older type plugs before the suppliers started stocking these new ones.
I refuse to expose myself and my wife to a ticking time- bomb.

Exactly, these plugs must carry 2.4kW of power running through them at maximum loading, sure most plugs won't be loaded that high, but I have seen the 15A version has the same thing on them (only difference is the bigger earth pin)

IMO, these plugs are a fire hazard.

I don't care if some idiot wears a neck chain and nearly electrocutes himself, you have to wonder about a person that wears a chain that long around a socket though.
Posted By: noderaser Re: In the name of safety - 11/19/09 08:00 AM
A pretty common occurrence with US grounded plugs... Don't think I've ever seen one with a completely solid ground pin. They are either circular & hollow, or U-shaped; the hollow ones break off all the time, which are generally found on molded plugs. The U-shaped pins are usually found only on the plugs you wire up yourself, and are thicker metal.
Posted By: Alan Belson Re: In the name of safety - 11/19/09 06:49 PM
Gents! Introducing: British Standard 1363! cool

http://en.wikipedia.org/wiki/BS_1363

Built like a brick outhouse, also suitable for braining rhinos! grin




Posted By: winston_1 Re: In the name of safety - 11/20/09 02:59 AM
Hey, this looks worrying. Do these pins ever break off and get left in the sockets? I'd rather risk a long neck chain than have bits of live pin sticking out over the kitchen worktop.

Surely time to reverse the insulated pins legislation.
Posted By: noderaser Re: In the name of safety - 11/20/09 05:31 AM
While I like the onboard fuse feature of BS1363, it seems a little oversized to me.

I get all sorts of interesting looks when I grab my needle-nose pliers to pull the broken ground pin out of an outlet...
Posted By: Alan Belson Re: In the name of safety - 11/20/09 06:27 PM
BS1363 does look oversized compared to other domestic plug designs, and it's not without its faults. Broken pins? Impossible! Most appliances and tools in the UK now come with a molded plug fitted, by law, to obviate miswiring by WWs or touching the pins on withdrawal or insertion. This should prevent wrong polarity, although that's rarely a problem with most domestic usage. The generous pin dimensions allow pin insulators without serious weakening of the pins. The faults are that it's possible to insert it upside down in some situations, thus opening and revealing the receptacle shutter & live parts, and it's possible to replace the fuse with a nail! Many variants exist, with different detail body shapes. They are still available as free units for DIY fixing to flex, with a myriad of cord grip designs, some good, some hopeless and in a variety of plastic types. I like the really solid bakelite versions and the ease with which they can be wired up with tools straight out of the kitchen cutlery box! blush The plug will naturally lie pins up, not a nice thing to tread on with bare feet! The fuse is absolutely necessary due to the UK Ringmain system. On the other hand, wallwarts which incorporate the plug pins are easy to design due to its generous dimensions. It is always easier to use, IMHO, than a Shuko once a bit of wear has occured in the plug or receptacle/socket, they slam in with a lovely CLUNK!
Posted By: Trumpy Re: In the name of safety - 11/21/09 04:42 AM
Originally Posted by winston_1
Hey, this looks worrying. Do these pins ever break off and get left in the sockets? I'd rather risk a long neck chain than have bits of live pin sticking out over the kitchen worktop.

Surely time to reverse the insulated pins legislation.


This standard is young, as are the plugs that were required by it.
The plugs I have referred to are used in commercial/industrial situations.

Now the alternative is using something like a 56 Series PDL plug and socket arrangement for your welders and other electrical tools.
The price of these plugs and sockets are out of this world.
When you are required to work in most places doing maintenance, you are met with the standard plug, not the 56 Series, mainly because no-one wants to spend the money to install proper socket outlets, hence a 1.5mm² cord going into a plug that was never designed to take that size of cord.

Sure we could make up a whole set of wired adaptors, but why in reality should we have to?

This legislation will never be reversed, it is set in stone now, it is a mind-set within the folks that make our rules. mad
Posted By: RODALCO Re: In the name of safety - 11/21/09 10:25 AM
Mike, those plugs are rubbish. I have also replaced several of them too.
First one to go was on our vacuum cleaner, replaced it with one of the old rubber extension lead plugs.
Other one was on an oil heater which I didn't trust as it ran too hot for my feeling and chopped it off. put one of the older tap on plugs on and no more excessive heat in the lead.

Typical a bureaucratic designed plug with no thought about burning a house down because of reduced ampacity to fit some stupid plastic sleeves on it.

I often go for a walk about on inorganic rubbish days and cut plugs and good leads of dumped appliances, these often yield good tap on plugs and other older style properly designed plugs from before the PC safety days.
Posted By: NORCAL Re: In the name of safety - 11/21/09 04:06 PM
Originally Posted by noderaser
A pretty common occurrence with US grounded plugs... Don't think I've ever seen one with a completely solid ground pin. They are either circular & hollow, or U-shaped; the hollow ones break off all the time, which are generally found on molded plugs. The U-shaped pins are usually found only on the plugs you wire up yourself, and are thicker metal.


GE had a solid pin on their cord caps, I think they got out of the wiring device biz though.
Posted By: wa2ise Re: In the name of safety - 11/24/09 12:42 AM
Originally Posted by noderaser
A pretty common occurrence with US grounded plugs... the hollow ones break off all the time, which are generally found on molded plugs.


Many of those were probably people wanting to plug it into a non-ground outlet, and had no adapter handy... frown

Back in the late 70's at college, my dorm had the crowfoot configuration outlets (the Aussie style pattern) in the laundry room, and whoever installed new washing machines took pliers and crushed the ground pin and twisted the blades on the NEMA plugs to make it fit into the crowfoot outlet... frown
Posted By: Alan Belson Re: In the name of safety - 11/24/09 02:42 AM
BS 1363 has the advantage of being designed in 1946 after we had the best part of Britain's cities flattened by nazi bombers, V Bombs and crude Ballistic Missiles- [ yeah, I know, Boo Hoo ] - and before the bean-counters began to run manufacturing. I was a kid then, and we used to collect schrapnel, lumps of Heinkels and bits of bomb casings as a hobby- it beats collecting stamps for street cred! We had to rebuild with minimal use of copper, which led to the Ringmain. It's existance keeps the BS1363 plug alive- because all those existing Ringmains need fused plugs which need Ringmains which....
If we redesigned today, those same VP bean-counters would inevitably come up with a material-lite product prone to the very faults that Trumpy pointed out in his OP. Anyone remember the free plastic toys out of the Kelloggs Corn Flakes boxes? A direct descendent of Shuko!
Posted By: pdh Re: In the name of safety - 11/27/09 04:40 AM
How does a fused plug need a ringmain? On this side of the pond, no ringmains, but there have been some fused plugs (had some on older Christmas tree light strings, presumably to protect the thinner wires of the string).
Posted By: Retired_Helper Re: In the name of safety - 11/27/09 07:07 AM
Originally Posted by Alan Belson
...We had to rebuild with minimal use of copper, which led to the Ringmain...

I've read explanations in the past of how the ringmains are wired, and I just can't picture how this saves copper. Would anyone want to explain? confused
Posted By: Texas_Ranger Re: In the name of safety - 11/27/09 02:16 PM
I always wanted to ask pretty much the same thing - what's the difference between one 32A ring mains and 2 16A radials using the same wire (but a few metres less because the ring needs to be completed) except 1 MCB or fuse? (not counting the arbitrarily maximum area served by radials in the UK). The possible load is exactly the same and you save some wire!

I've even seen fused contour plugs! (1000W movie light).
Posted By: uksparx Re: In the name of safety - 11/27/09 05:53 PM
Well...I think it worked like this... in the old days of BS546 (round pin plugs) you were only allowed one 15Amp socket per circuit. That meant for every socket you had to run a separate cable from the fuseboard, thus, wiring a whole house meant lots of cable runs unless you only had one or two sockets. After the war they wanted homes to be more modern and have more than a couple of sockets for the whole house. It was then they came up with the ring system - one big loop of cable around the house - and wonder of wonders - you could have one socket in each room!!! Which is about the maximum they ever fitted back then and indeed it seems until the 1970s. All this and if you planned the run right, you could use very little cable, or at least that was the theory. In these more modern times of many sockets and not so short supply of copper the ring system is a bit pointless. Also in my view as a contractor, it can become very dangerous too. I have often found cases of one side or more of the ring becoming "not a ring" for various reasons and then the whole load is being carried on one piece (in fact a radial) of 2.5mm cable and often protected by a 30Amp rewireable fuse of all things!!! I personally never install ring circuits any more for this and other reasons.
Posted By: Retired_Helper Re: In the name of safety - 11/27/09 06:45 PM
Uksparx, thanks much for your detailed explanation. Now I get the picture! laugh
Posted By: Texas_Ranger Re: In the name of safety - 11/29/09 05:41 PM
So basically it was all due to the arbitrarily chosen maximum number of one socket per radial?
Sounds pretty crazy from today's point of view...
Posted By: uksparx Re: In the name of safety - 11/29/09 11:25 PM
Indeed it appears that was the case - I agree, totally crazy! You have to remember this is Britain and we are very good at following rules, however mad they seem!!
Posted By: Texas_Ranger Re: In the name of safety - 12/01/09 10:43 PM
Following rules is quite right (in most cases I guess wink ) but rules have to be made by someone... however, common sense doesn't seem to be the strong side of lawyers and politicians in any country of the world (if they have it, they certainly don't like to apply it!).
Posted By: renosteinke Re: In the name of safety - 12/02/09 01:16 AM
TR, I think you've hot the nail on the head there.

No longer is the emphasis on 'making things work.' Rather, it is a desire to 'be beyond criticism,' or to have 'met requirements.' There's an overwhelming attitude that everything is interchangeable.

What fool would make, or buy, a $10 item when theres a $1 version available?

My answer? The same "fool" who buys a $50,000 BMW in preference to the $5000 Yugo.
Posted By: Yoopersup Re: In the name of safety - 12/02/09 07:29 PM
Buy Rags you get Rags I was told when Young & Theres a lotta Truth to that statment.
Posted By: djk Re: In the name of safety - 12/05/09 10:25 PM
The old, and indeed the current, British regulations are a bit fixated on the notion that appliances MUST be protected by quite low rated fuses to prevent fire due to spontaneous combustion of cables.

This led to a situation in the old BS546 system (the old round-pin British plugs) where small appliances, with thin cords e.g. radios, lamps etc had 2 or 5 amp plugs which were connected to socket outlets that were on 2 or 5 amp circuits and so on. Each plug was incompatible with every other socket, preventing someone from 'accidentally' plugging a 5amp appliance into a 15A circuit and so on.

The practice elsewhere was to assume that appliances could survive a 15 or 16Amp fault without major problems.

BS1363 basically allowed the rigid British over-current protection methodology to continue in an era where people needed more than one socket outlet per circuit.

i.e. each appliance is individually fused by the plug, and the fuse is rated appropriately for each situation i.e. 1 to 13amps

The reality however is that people tend to fit a 13amp fuse regardless. So, it's not a heck of a lot safer than a 16A radial system.

Posted By: Texas_Ranger Re: In the name of safety - 12/11/09 12:09 AM
I do remember an ancient UK reel tape recorder with an insanely small flex, maybe something equivalent to 0.35mm2 or maybe even smaller. It looked like the wire commonly found inside radios connecting 9V batteries to the board.

The general idea is that the appliance limits the load, so overload doesn't need to be taken into consideration for appliance flex sizing, and short circuit protection can be much higher than overload protection. That's why most regs. allow you to run 0.75mm2 flex off a 16A circuit.

I'd really love to know what the wiring world might look like in 50 years.
Posted By: LongRunner Re: In the name of safety - 06/07/15 05:32 AM
If I recall correctly, it's the 2000 revision of AS/NZS 3112 that enforced the transition to insulated pins by 2005. It was followed by the 2004 revision which upgraded the strength requirements for the pins, and I'll admit that most of the newer plugs aren't too bad (although it's obviously still impossible to match the full strength of solid uninsulated pins). Still, it was a typical case of politicians acting before they think. rolleyes

Originally Posted by aussie240
It's not just the flimsy pins on the plugs now, but the flex attached to most 2.4KW appliances in recent years is underrated and becomes too warm for my liking. Proper 1.5mm flex and a chunky old stock bakelite plug fixes the problem.

I have to admit, I find it funny that you say that when you say on your personal website, in the page on building replacement resistance cords:

Quote
This is also the first time I've used a line cord resistor, and from all the stories I've read I was curious about the amount of heat given off. It certainly isn't excessive, and I don't see it being a fire hazard.

You acknowledge that its dissipation is 32.4W (0.3A through 360R;) over 1.8m, which gives 18W per metre of cord. While the worst-case resistance of 0.02R; per metre of 1.0mm² (32/0.2) flexible wire (with tinned conductors; with bare copper, as is usually the case, it's a little lower), counting both active and neutral, and accounting for a 16% resistance rise from 20°C to 60°C, gives a dissipation of 4.64W/m at an accurate 10A, or 5.6144W/m at most if you allow for 10% above the nominal current (11A actual).

But for what it's worth, I don't think it's under-rated per se. It's just the result of a typical bureaucratic compromise regarding the designated room temperature, which the previews of IEC 60320-1 and 60320-2-2 state as "not normally exceeding 25 °C, but occasionally reaching 35 °C" (whatever we're supposed to make of that), and presumably the same applies to the official cord ampacities. But I expect that upsizing the cord conductors to 1.5mm² (10A) and 2.5mm² (16A) would be enough to reliably operate those connectors at 40°C ambient (especially given that the copper wires act as a heatsink-of-sorts for the contacts). Still, I wouldn't suggest officially adopting such an upgrade until they stop bundling yet another cord with each new PC/TV/etc., or it would result in even more valuable copper ending up in landfill.

Originally Posted by noderaser
A pretty common occurrence with US grounded plugs... Don't think I've ever seen one with a completely solid ground pin. They are either circular & hollow, or U-shaped; the hollow ones break off all the time, which are generally found on molded plugs.

It seems to depend on who made the particular plug, whether it will break or not. The one NEMA 5-15 to IEC (60)320 C13 cord that made its way into my stash, made by I-Sheng (who, judging by the sheer quantity of cords I have from them, are one of the largest manufacturers), has quite a solid ground/earth pin. Incidentally, I also have a batch of cords they made in (seemingly) the early insulated-pin days, so I got one out to compare – it's just as strong as any of the post-2004 models. So it looks like they, at least, are more competent than the politicians.
Posted By: electure Re: In the name of safety - 06/08/15 03:14 AM
LongRunner,

Aussie240 hasn't logged into ECN for 10 months.
The post was made in Nov 09.

You revived and posted in a 6 year old thread.
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