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Twin & earth identification

I have been given some T&E cable that are supposed to be 1.5 & 2.5 (1.5 for a basic lighting circuit and 2.5 for 6 sockets)...Seeing as they both look identical I have taken a cable out of each and measured them in a drill gauge...they BOTH come in at 1.7mm.......neither of this is 1.5 or 2.5??? (this size is measured with the insullation tripped back - so just the copper core)

I am NOT doing the installation, just running the cables of the circuit.....I dont want to waste time / money running the wrong cable

HOW can i identify the two sizes

2 Answers from MyBuilder Electricians

Best Answer

If you have a look on the PVC outer sheathing of the cable (The grey part) it will have stamped at intervals identifying markers such as its size, British standard code etc. For 2.5 mm T&E simply look for the imprinted stamp of 2.5, likewise for the 1.5 mm cable. In any event over sizing your cable is not a problem in its self it will just cost you more money, just be sure not to undersize it especially for your power circuit. Hope this helps!


Answered 21st Oct 2012

You are measuring the diameter of the conductor. 2.5/1.5 relates to the cross sectional area (CSA) of the conductor. 2.5 T+E and 1.5 T+E are visibly different so I would assume the cables you have been given if look identicle are identicle.
2.5mm T+E has a 1.5mm earth 1.5mm T+E has a 1.0mm earth.
If this is not enough information to tell the difference you will have to go on line to get calculations for working out cross sectional area.


Answered 21st Oct 2012

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