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

[MTMT]

Hi guys. We have a big problem here that need urgent attention if possible.

Correct me if i am wrong;

BS1363 plugs, for class 2 appliances, the earth pin is plastic due to unearthed or double insulated object.

Many standard uk plugs come with full metal earth pin, but why is half-insulated earth pin not allowed?

And i have been spending the whole afternoon looking for the official BS documents related to this "plastic" or "full metal" earth pin.

Please help

 

[JohnD]

Hi guys. We have a big problem here

What is your big problem?

 

[MTMT]

Hi guys. We have a big problem here

What is your big problem?

um...why is the earth pin cannot be half-insulated...

 

[MTMT]

Hi guys. We have a big problem here

What is your big problem?

um...why is the earth pin cannot be half-insulated...

under the newer standards, the live and the nuetral pins are half insulated for extra safety, but why the earth pin cannot be half-insulated too? These cables apparently are illegal...

 

[JohnD]

Hi guys. We have a big problem here

What is your big problem?

um...why is the earth pin cannot be half-insulated...

That's not a problem, it's a question.

Have you actually got a problem?

Or is it a question in your course homework?

 

[MTMT]

That's not a problem, it's a question.

Have you actually got a problem?

Or is it a question in your course homework?

It is a question my mate was asking me ...

 

[JohnD]

not a big problem then

 

[jpdw]

That's not a problem, it's a question.

Have you actually got a problem?

Or is it a question in your course homework?

It is a question my mate was asking me ...

You could always turn back to your mate and asking him what he thinks the reason might be! Might be interesting to hear his ideas!

 

[MTMT]

not a big problem then

So does that mean half-insulated earth pin conform with the British Standard?

 

[MTMT]

That's not a problem, it's a question.

Have you actually got a problem?

Or is it a question in your course homework?

It is a question my mate was asking me ...

You could always turn back to your mate and asking him what he thinks the reason might be! Might be interesting to hear his ideas!

Because we were searching articles on the net, and many did not state whether a earth-pin can be insulated or not. These articles states it should be either full plastic earth pin or full metal earth pin. I believe he sold a cable and this customer is pestering him about it...

 

[jpdw]

Till someone knowledgable comes along I'd guess plastic only if there is nothing else to connect the earth to. Any/All other plugs would then have full metal to ensure maximum possible conductive surface (for safety).

 

[Spark123]

What would be the point in half insulating it anyway? The phase and neutral (both live conductors) are half insulated so little fingers etc cannot come into contact with them when the plug is being plugged/unplugged. The earth on the other hand, is connected to the metalwork on class 1 appliances, if the socket is metal the metalwork will be earthed etc etc. Coming into contact with correctly earthed metalwork is not a problem.
There is absolutely no point in half insulating it, actually I would go as far to say it is dangerous to do that if the plug were to be used for a piece of class 1 equipment as the earth conductor needs to be made first and the connection is near the surface of the socket hence an insulated earth pin would break the CPC connection. With the live conductors, the connection is set back inside the socket.

 

[MTMT]

Till someone knowledgable comes along I'd guess plastic only if there is nothing else to connect the earth to. Any/All other plugs would then have full metal to ensure maximum possible conductive surface (for safety).

Thank you anyway.

The reason why the 2 live and neutral pins are half insulated is because of safety incase the plug is half plugged into the wall socket and somebody is touching it.

(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)...

 

[Spark123]

So what about all the class 1 equipment out there?
Should we ban all metal sockets too?

 

[salem2000]

Maybe if it were half insulated it could wear unevenly and cause the plug to catch on the conductor shield thingy, and cant be pulled out when needs must.