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#137940 08/07/03 05:32 AM
Joined: Aug 2001
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This does indeed seem to be a popular topic of conversation.

By the way, am I the only non-North American who likes the elegance of the NEMA configurations?

#137941 08/07/03 09:10 AM
Joined: Jul 2003
Posts: 36
J
Member
The main obstacle to eliminating the British style plug is the requirement for a fused plug to accomodate the ring circuit. Why does the plug have to be fused? Why not the socket? Why can't the British just have a fused/circuit breakered Schucko friendly type socket? This way a Schucko plug is protected when plugged into a British ring. If there is an instance where no ring is used, a non-fused type socket could be installed. This would be the most economical and sensable, no?

It would be a major cost savings for manufacturers who would only have to stock and supply one type of plug and for consumers who would not have to rely on adaptors or having a safety problem forcing a euro style plug into a British socket.

Also, I've seen the British style sockets in Singapore and Malaysia.

#137942 08/07/03 10:07 AM
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Posts: 1,498
Likes: 1
C
C-H Offline
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DJK,
Quote

The only problem I would have with that design is that it doesn't sit flush with the wall when in use like BS1363 and some italian plugs.

No, but the recess is only 12 mm, much less than the Schuko.

Quote

Could you make it flat?

[Linked Image] The whole point is that the plug body is assymetric, which means that the ungrounded plug is polarised. (Well, only in sockets designed for it of course.)

Quote

Why round pins? Don't they produce all kinds of spring/contact problems?

Because all sockets already have round pins?

The plug manufacturers already have the tooling for round pins of this size. And the socket manufacturers already have the tooling for sockets contact to accept them.

I wanted a standard which could be combined with the Shucko, French and Danish standard simply by adding a third hole the these sockets.

One shouldn't forget that 500 miljon of the 550 miljon Europeans live outside the UK.

Quote

Wouldn't blades or at least squared pins like UK plugs make the socket contacts easier to manufacture?

Don't know. I can't see how you could possibly make socket contact simpler than that found in Schuko sockets. You would probably get a better connection with squared pins, though.

[This message has been edited by C-H (edited 08-07-2003).]

#137943 08/07/03 10:17 AM
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C-H Offline
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Quote

The main obstacle to eliminating the British style plug is the requirement for a fused plug to accomodate the ring circuit. Why does the plug have to be fused?

I don't think it needs to be fused.

The requirements a socket/plug has to meet when used with a ring:

1.) Not overload the ring on either side. This problem exist even if you use fused plugs. If don't put a socket at the first and last 20% of the ring, there is no problem.

2.) The socket must handle the current passing through it and it must be impossible to overload it. The problem has obviously been solved for the double sockets used today. Just make the terminals for 20A @ 2.5 mm2) and the capacity between them the same.

3.) In case of a phase-neutral short, a protective device must break the current. A fuse in the plug or socket is one way. Another is to rely on the circuit breaker in the consumer unit. It would work with a 32A B MCB. Even if the you have 70m ring and attach a 30m 1.5mm2 extension cord.

#137944 08/07/03 03:08 PM
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C-H Offline
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I thought this would be easy. Now I have 13 pages and counting. [Linked Image]

Hutch,
how are you doing on your system? [Linked Image]

#137945 08/07/03 08:34 PM
Joined: Oct 2002
Posts: 134
D
Member
C-H,
I don't like to throw a spanner in the works as I can see you have put a great deal of thought into this, but for use on a UK ring main system either the plug or socket has to be fused. My reasoning for this would be:
1) Possible overloading of the socket, as I assume that multi-socket adapters & power strips would also be unfused & fed by a 30/32A fuse or breaker. Existing BS types have a 13A fuse to prevent this.
2) No sockets in the first & last 20% of the circuit would be very difficult to achieve in practice and almost impossible for retrofit applications, where sockets are just being replaced with the new standard.
3)You state that a 32A B type mcb will adequately protect a 1.5mm cord, what about the more common 0.75mm cords or even 0.5mm cords still found here?
There is also the problem that an enormous proportion of UK installations still have primitive rewirable fuses "protecting" the circuits, with no rcd protection at all. This situation will persist for some years to come. If a homeowner/diyer decided to change their sockets to the "Neoplug" type on one of these installations, it could be quite hazardous.

I would concede that all these problems disappear if we change to 16/20A radials, but is "Neoplug" better & safer than the existing BS 1363?


Paul,
I suspect you may be in a very small minority of non- North Americans with your preference for NEMA plugs, they always appear slightly flimsy to me (15A 125V type).

#137946 08/08/03 06:14 AM
Joined: Aug 2001
Posts: 7,520
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I agree with David on the fusing. If we are going to keep a 30/32A ring, then there must be fusing either in the wall socket or the plug. Those 0.5mm lamp flexes (and their pre-metric equivalents) are still pretty common.

I think you all know by now that I'd like to see ring circuits abandoned [Linked Image], but even if they were removed from our "regs" today, they would still be in use for many, many years.

Selling a fused version of the "Neoplug" outlet for the U.K. market would be a possibility, although each socket would have to be fused at 13A so you'd lose the closer protection of lower-rated fuses for the smaller cords.

You can also bet that the average DIY bodger would be quite likely to go around the house and fit unfused versions to an existing ring (the fused versions being peculiar to the U.K. and produced in smaller quantities would inevitably be more expensive). That's down to his ignorance, of course, and I'm not suggesting that as a reason not to go ahead with the plan -- I'm just looking at the possibilities.

In some homes it might be possible to split a ring into two 16/20A radial circuits which might be an option for conversion to a new system, but it's not always going to be easy. Right from the beginning, the domestic ring circuit has been allowed to feed a floor area of up to 1000 sq. ft. (later 100 sq. meters), and there are still plenty of houses where just one ring feeds every socket.

On the NEMA plugs, I agree that there are some which are a bit flimsy, but then I've seen some poor quality BS1363 stuff too. Good quality NEMA connectors are fine.

What I like is the way that the pin configurations permit suitable connections and restrict others, i.e. a 5-15 receptacle (standard 120V 15A) will accept a non-polarized two-pin plug, a polarized two-pin plug, or a 3-pin grounding plug. All three 15A plugs will also fit a 20A receptacle, but not vice versa.

Twist the pins around and the same applies to 240V outlets.


[This message has been edited by pauluk (edited 08-08-2003).]

#137947 08/08/03 01:07 PM
Joined: Sep 2002
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C
C-H Offline
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Quote

I don't like to throw a spanner in the works

You're welcome. Rather you today than someone else tomorrow. [Linked Image]

The thing is that Britain doesn't have to be included in the system. I'm more interested in countries like India.

There is no need to replace the BS 1363 plug today in Britain, but you could introduce a new plug for heavy appliances only, 13A-16A. In thirty years one might reconsider this. Even suggesting replacement to a wider audience will probably get you a Sun-burn... [Linked Image]

Quote

1) Possible overloading of the socket, as I assume that multi-socket adapters & power strips would also be unfused & fed by a 30/32A fuse or breaker.

If the Americans and Australians can get by without having a overcurrent device that corresponds to the socket rating, why would it not work in the rest of the world? There is no problem with designing the socket so that the terminals can handle the load. If it works with the current sockets, why wouldn't it with the new?

No, I'm going to propose the introduction of overload/overheat protection and primitive short-circuit protection on power strips and cable reels. It hasn't anything to do with a new plug, it should be on the current unfused systems.

Quote

2) No sockets in the first & last 20% of the circuit would be very difficult to achieve in practice and almost impossible for retrofit applications, where sockets are just being replaced with the new standard.

Yes, but the same requirement effectively applies to BS1363 sockets today. One single socket can be placed closer to the ends.

Quote

3)You state that a 32A B type mcb will adequately protect a 1.5mm cord, what about the more common 0.75mm cords or even 0.5mm cords still found here?

It will if the cord is corresponding shorter. (About 10 m for the 0.5 mm2 cord)

The risk is in fact greater with an ordinary 16A type C circuit. [Linked Image] [Linked Image]

Quote

There is also the problem that an enormous proportion of UK installations still have primitive rewirable fuses "protecting" the circuits, with no rcd protection at all. This situation will persist for some years to come. If a homeowner/diyer decided to change their sockets to the "Neoplug" type on one of these installations, it could be quite hazardous.

Include an instruction sheet informing that you may not do this and the reasons. I doubt there will be a rush to replace sockets. If people do, it will be to hook up the new washing machine, which has a short and heavy cord.

#137948 08/08/03 05:51 PM
Joined: Aug 2003
Posts: 15
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Plugman Offline OP
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Just to put a slight tangent on this thread ~ If BS1363 hadn't been developed in the 1940's, would we (UK/Ireland) still be on BS 546 ?
I would have kept it, but uprated the '5amp' plug to 10amps, and the '15amp' to 16amps.
As pauluk has previously mentioned, the old 5amp is a handy size physically, and at 10amps, would have covered most domestic uses, leaving the 16amp for heavy domestic uses only.

#137949 08/08/03 07:38 PM
Joined: Jul 2002
Posts: 8,443
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Plugman,
Welcome to ECN. [Linked Image]
Great to have you on board!.

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