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#138371 - 09/03/03 04:22 PM Polarise schuko?
djk Offline
Member

Registered: 12/26/02
Posts: 1269
Loc: Ireland
I was just thinking, for safety reasons schuko isn't exactly the best design of outlet as it's unpolarised. However, there is a very simple sollution.

1) Drop CEE 7/IV (Schuko) and replace with the compatable CEE 7/V (French) which is polarised when used with grounded plugs and pretty much fully backwards compatable with normal CEE 7/VII plus which allow for both grounding options.

2) make non grounded europlugs include a small moulded protrusion on one side, big enough to not fit past the french grounding pin but still compatable with old schuko and italian/danish/swiss outlets.

Basically a europlug with oneside bulging out.

This would prevent it from being inserted the wrong way into a French style outlet.

(Recessed swiss outlets wouldn't be a problem as you could pretty much make the bulge the same shape as a grounded swiss plug, just without the 3rd prong)

[This message has been edited by djk (edited 09-03-2003).]

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#138372 - 09/04/03 01:47 AM Re: Polarise schuko?
C-H Offline

Member

Registered: 09/17/02
Posts: 1508
Loc: Stockholm, Sweden
More importantly the CEE 7/V socket is less prone to damage and offers better resistance to water. I'm with you.

And require that all grounded plugs are CEE 7/VII.
 Quote:

2) make non grounded europlugs include a small moulded protrusion on one side, big enough to not fit past the french grounding pin but still compatable with old schuko and italian/danish/swiss outlets.


My 'neoplug' - ungrounded version - meets this critireon.

A more important feature of the protrusion or assymetric body is that it prevents insertion into 2.5A sockets. This allows a 16A rating without risk of fire.


[This message has been edited by C-H (edited 09-04-2003).]

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#138373 - 09/04/03 07:32 AM Re: Polarise schuko?
djk Offline
Member

Registered: 12/26/02
Posts: 1269
Loc: Ireland
I just think it's a very simple and much less expensive sollution to the whole problem of polarisation in Europe. It would be as easy to implement as the US polarised plug was.

The exsisting sockets wouldn't have to change, the French & Belgian system would become fully polarised and eventually, over say 20-30 years the non-polarised plugs would simply slip out of use.

Denmark and Italy might even jump on board even although I can't see the swiss or british/irish systems changing for a LONG time.

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#138374 - 09/04/03 08:29 AM Re: Polarise schuko?
C-H Offline

Member

Registered: 09/17/02
Posts: 1508
Loc: Stockholm, Sweden
The question is why you would want a polarised plug. Exactly what is it good for?

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#138375 - 09/04/03 09:16 AM Re: Polarise schuko?
SvenNYC Offline
Member

Registered: 08/19/02
Posts: 1685
Loc: New York City
In the case of table lamps, a polarized plug is usefull because (assuming everything is wired properly), the switch will be on the "HOT" side, which leads to the center contact.

The metal screwshell is then the neutral and this part will not accidentally become "live" if the plug is reversed.

This way, if the lamp is without a bulb, but still plugged in, an idiot will not get a shock from sticking his or her finger in the lampholder.

Of course for my own use, I think these things are an annoyance and I always curse whoever came up with these damned things. Sometimes I've replaced the plugs with standard ones.

However when I rewire and replace the lampholder on an old table lamp or attach a new cord on an appliance for a relative or friend, I ALWAYS connect the conductors to the proper screw terminals on the lamp socket and screw on a polarized dead-front (totally enclosed) plug, or use a cordset with a moulded-on polarized plug and make sure the switch is on the live side.

It protects me from anyone yelling at me because they got bitten by doing something stupid.

[This message has been edited by SvenNYC (edited 09-04-2003).]

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#138376 - 09/04/03 09:28 AM Re: Polarise schuko?
C-H Offline

Member

Registered: 09/17/02
Posts: 1508
Loc: Stockholm, Sweden
I think that is a problem that should be adressed by redesigning the lampholder.

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#138377 - 09/04/03 10:26 AM Re: Polarise schuko?
djk Offline
Member

Registered: 12/26/02
Posts: 1269
Loc: Ireland
Polarised plugs make a lot of sence. Schuko was designed for supplies that used 127V to make up the 220V supplied to the applience. Both terminals were hot, same with the Italian system.

However, with the use of 230V + Neutral bonded to ground it makes no sense not to polarise the plugs!

Most appliences use single pole switching so when the plug has the blue wire on the hot side the applience parts remain live. Light sockets are an obvious danger. Fusing on the neutral side is also considered dangerous and may result in a non polarised system.

I just think it would be a general safety benefit and very easily achievable situation.

I also fail to see why we need to have CEE 7/IV and CEE 7/V. It's just unnecessary duplication and I think the CEE 7/IV (schuko system) is inferior in this instance. The French version is the obvious candidate for a replacement. Lots of advantages.. it's less complicated, more robust, polarisable, fits the same plugs, takes up the same space and can easily fit into a shucko box.

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#138378 - 09/04/03 01:06 PM Re: Polarise schuko?
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Polarization of plugs seems to be of far greater concern to the British/Irish committees than in Continental Europe. Even though the French receptacles are polarized, many electricians don't seem too worried about which way they wire them anyhow.

The ironic thing about the lampholder question is that the U.K. -- with its insistence on polarized plugs -- has the double-contact bayonet holders in most table-lamp applications.

There are cases where polarization of the plugs is desirable, but I think that in some instances the case is overstated. If the plug on, say, a portable drill or a kitchen blender is reversible, it doesn't really matter.

(OK, fellow Brits, go ahead and call me a traitor... ).

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#138379 - 09/04/03 01:19 PM Re: Polarise schuko?
SvenNYC Offline
Member

Registered: 08/19/02
Posts: 1685
Loc: New York City
The last blender (a Waring "Blendor") I changed the (crumbling) flex on didn't have a polarized plug on it.

I used a polarized cordset. Wired the thing so the switch was on the hot side. The casing was metal.

You're right. I don't understand what the purpose is.

I personally think it's the Chinese manufacturers' fault. They all seem to think that ALL UL-Listed cordsets MUST be polarized - and that's pretty much all you can find these days...so by default...guess what.

I once wrote UL asking why they insisted on polarization of double insulated and transformer-equipped devices like cassette players and clock radios.

The reason they said is because of fusing. Some of these devices actually have a safety fuse inside....so they want the fuse on the "hot" side, I guess. And it's true. One boombox I opened up had a miniature glass fuse snapped in a clip on the PC board that held the transformer and the rest of the power supply components.

[This message has been edited by SvenNYC (edited 09-04-2003).]

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#138380 - 09/04/03 02:04 PM Re: Polarise schuko?
djk Offline
Member

Registered: 12/26/02
Posts: 1269
Loc: Ireland
yeah most british lampholders will electrocute you no matter which way you stick your finger in!

The lesson being: don't stick your finger into a lamp holder!

I still fail to see why lamps can't have 2 pin connectors on the bottom.

Thermal expansion must have been an issue in the old days. Although edison screw fittings are terrible for that. if the bulb connector expands you're really jammed in!


[This message has been edited by djk (edited 09-04-2003).]

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