Earth wire too short

adm

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Hi all,
Any help on the following would be most appreciative.

Just finished decorating a bedroom at my daughters and the last job is i want to change the plastic socket face plates for new plastic ones the trouble is that the earth wires connected to the face plate are very short and fitting a new one would be rather awkward,is there any way i can extend the earth wires to give me more access when fitting the new faceplate, these will be conceled within the back box.
Could i use in line connectors or fitting existing earth wire into earth connection that is fitted to the plastic back box and then a fly wire connecting this to the socket itself.
Cheers.
 
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Extend the CPC's using insulated terminal block and connect to the sockets earth terminal . The plastic box doesn't require earthing.
 

SFK

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Yes, if the wires reach put your earth wires into the earth connection that is fitted to the plastic back box and then a fly wire(with a yellow sleeve on) connecting this to the socket itself.

The terminal that is in the back box will work the same as using a insulated terminal block.

If the wires do not reach the connection in the back box use a insulated terminal block and a short length of earth wire to the socket.

The yellow green sleeve earth can be bought in massive lengths from DIY shops or short lengths from eBay.

Sfk
 

adm

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Thanks all for your replys managed using 15a choc blocks that i had.
 
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Other than under (rare) fault conditions, no current at all will flow through the 'earth' connection!

And when there is a fault the Earth connection has to carry the fault current for as long as it takes for the protective device to detect the fault current and operate.

If the protective device is an RCD then it will operate very quickly, if the only protective device is a fuse or an MCB then the fault current could be flowing for several seconds.
 
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Would you use a 16A junction box? You also have the risk of what happens if one of the wires in the ring falls out.

 
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And when there is a fault the Earth connection has to carry the fault current for as long as it takes for the protective device to detect the fault current and operate.
Indeed - but do you seriously believe that joining the 'earth wire' in a "!5A" connector block would have any relevance to that situation?

When conductors are joined in a connector block, most of the current travels between the contact between the two conductors, not through the material of the block. The 'current rating' of the block is really pretty irrelevant- what matters is the physical ability of the terminal to 'comfortably' accommodate the conductors.

In fact, if we are scraping barrels, I would go further, and would suggest that it is theoretically undesirable (in terms of quality/reliability of the electrical connection) to join conductors in a screwed terminal which is appreciably larger than that which can comfortable accommodate the conduction - in context, I would feel it less desirable to join two 1.5 mm² conductors in a terminal designed for, say 3 x 2.5 mm² conductors than in smaller one which was not much larger than the minimum which would comfortably accommodate the 2 x 1.5 mm² conductors.

Kind Regards, John
 
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What is it about a connector block that would limit the CCC to 15A?

The metal is considerably larger than a 1.5mm² 20A conductor and the screw typical of all such terminals.
 
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When conductors are joined in a connector block, most of the current travels between the contact between the two conductors, not through the material of the block.
I would assume that would depend on how exactly the block was used.
 
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I would assume that would depend on how exactly the block was used.
It would, but if one connected the conductors only to 'one side' of the connector block, so that current was flowing through through the material of the block, then i imagine that the material of even a "5A", let alone "15A" connector block would probably have a greater CSA than the 1.5mm² conductors being connected.

I stick to my belief that, in this context, the 'current rating' of the connector block is essentially irrelevant, and that what matters is the ability of the terminals to accommodate (without too much 'spare space') the conductors.

I therefore also stick to my belief that it is actually undesirable to use a (physically) 'over-sized' connector block, and that becomes even greater a consideration if one adopts the method of using the block that you imply ... to put just 1 x 1.5 mm² conductor into a terminal large enough to accommodate, say, 3 x 2.5 mm² ones is, in my opinion, pretty undesirable.

Kind Regards, John
 
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