BS 1363 UK 3 pin plug-why Earth pin cannot be half insulated

[bernardgreen]

The thread is three years old.

Do you have a photo of an MK plug with a half insulated earth pin ?

Is it genuine MK or is it **** Kong Electrics.

You are right about some items made in the far east being poor quality.

 

[alanheathrobinson]

No, MK made the socket, not the plug.

 

[bernardgreen]

Sorry, I mis-interpreted your posting.

The sockets are designed to ensure the earth connection is made first before the live and neutral pins reach the contacts inside the socket. Hence the sockets earth contacts are as close to the front of the socket as possible.

So half insulated earth pins on plugs are not acceptable if the equipment requires an earth.

 

[alanheathrobinson]

Exactly!

 

[ban-all-sheds]

The thread is three years old.

Yes, but resurrecting it gave us all a fresh opportunity to marvel at the ideas put forward by the OP.

(1) If the plug is half plugged into the wall, and there's a power surge etc causing current flowing through the earth, half insulated earth pin in this case is useful (the person wont get full blown shock if he/she is touching it).

(2) But, contradictingly, if there's a high current flowing through the earth and the pin is half-insulated with plastic, then the plastic will potentially melt and cause hazzard. May be that' why the earth should be full metal?

I believe (2) is likely to happen more than (1)...

Class.

 

[alanheathrobinson]

WRONG !!

If there's a connection or partial connection between live and appliance earth, the earth connection ensures the current flows safely to ground, and that the user isn't at risk of getting a shock.

If the connection is a short circuit a fuse will blow or breaker trip. If RCDs are in use, the imbalance between live and neutral currents will cause the RCD to trip.

There is absolutely nothing about sleeved earth pins that makes them safer.

Regards, Alan Robinson.

 

[tonyelectric]

When I worked at a cable manufacturers years back one of the things we did was moulded plugs, the plastic earth pin the OP refers to has naff all to do with double insulation or safety and a lot to do with cost, we offered 3 options for DI leads

1/. C**ppy plug with plastic earth, v cheap but not reccomended for frequent plugging in, pulling out, OK for TVs & VCRs that get left in.

2/. Plug with rolled sheet brass pins (hollow so cheaper)

3/. Plug with all pins solid brass most expensive

as it is DI the metal earth pin is not connected
obviously the L & N were half sheathed, I have half a die (the top half) for a hotpoint branded plug that I use as a doorstop

 

[MalcofArabia]

WRONG !!

If there's a connection or partial connection between live and appliance earth, the earth connection ensures the current flows safely to ground, and that the user isn't at risk of getting a shock.

If the connection is a short circuit a fuse will blow or breaker trip. If RCDs are in use, the imbalance between live and neutral currents will cause the RCD to trip.

There is absolutely nothing about sleeved earth pins that makes them safer.

Regards, Alan Robinson.

Alan are you saying that you have half sleeved earth pined plug tops that are used with class 1 equipment?

 

[alanheathrobinson]

What I have (or to be more accurate had - the offending article is in the hands of Trading Standards at the moment) is a BS1363 to IEC C13 'kettle lead' that could be used with ANY class of equipment.

There are loads being flogged on eBay right now. For example, see ....

http://cgi.ebay.co.uk/13A-250V-UK-P...uting_CablesConnectors_RL&hash=item3a615e27e8

.... and there are plenty more.

Regards, Alan Robinson.

 

[tonyelectric]

Could it be as this is from Hong Kong that other countries have modified BS designs for use in their own territory like South africa have done with the 15A plug and India the 5A plug.

 

[alanheathrobinson]

I'd be surprised. Other countries do have their own standards, but AFAIK they are based on BS1363.

And some of the sellers I found are UK based.

Not being one for conspiracy theories, I reckon design cock-up is the most likely explanation, coupled with bad regulation. Trading Standards tell me he licence number on the one I found was false.

Regards, Alan Robinson.

 

[Monkeh]

Also note how it's advertised as 13A. C13s are only rated for 10A.

 

[tonyelectric]

There is a 13A version of this pin configuration, I have two of them in use on stage lighting dimmerboards, purchased them from RS not all that long ago, but most as you say are rated for 10A

 

[Monkeh]

Not a standard one. There's always C19..

 

[tonyelectric]

No these are c13 type, no notch in long side, 1.5mm flex with 230V 13A moulded into the plastic of the IEC end, they are used to feed W.J.Furse Delta Dimmers which were designed to take them as a feed cable and clearly states max load 3000W on the dimmer next to the IEC socket.

Rapid electronics have a coiled one specified as 13A, although in 1.0mm flex that might run a little warm!!