How to measue cable size

dreaddan

I'm just had a look at the cable in the back of the cooker socket to see if I'm going to need to get a spark in to replace the circuit or not.
Am I right in saying that to measure the cable is just to measure the width?
If so am I right in saying a 4mm cable is rated at 30A and is ok for a cooker circuit?

Cheers

brightontraveller

The outer pvc sheathing varies from manufacture, construction of outer sheath etc so measuring it would not be an accurate or recommended way to find the size, you would also need to take into account method of installation of cable temperature etc to be able to just say 4mm cable takes 30 amps without really taking these into account would not be considered good/safe practice

For example In 2 core multi-core p.v.c.-insulated cables

Conduit in thermal insulation would be 23.0
In conduit on wall would be 30.0
Clipped direct 36.0
As you can see there is a variation of nearly 30 % with method of installation using standard cable this site may make it a little clearer my opinion is if you are unable to identify the cable etc you should maybe think of calling a qualified person to do so

You would also need to take into account the fuse that feeds this circuit (the basic idea is fuse blows before cable burns etc) and the load of the cooker, (e.g is it 30 amp or 36 amp load when cooker is used) and the cooker outlet rating if you are unable to identify the cable etc you should maybe think of calling a qualified person to do so

http://www.tlc-direct.co.uk/Book/4.3.9.htm

ormus

these are a basic guide sizes for typical applications.

1.0mm 14a 3.25kw lighting.

1.5mm 18a 4.25kw lighting.

2.5mm 24a 5.75kw power circuit.

4.0mm 32a 7.75kw power circuit & shower.

6.0mm 40a 9.75kw shower & cooker.

10mm 53a 12.9kw cooker.

dreaddan

Sorry I should have said that's the core width.
I'll read that link.

edit: I should explain what I'm doing - were having a new electric cooker and a gas hob installed next month. I'm just doing some groundwork to see if I need to get a new ring so I can budget for that being done as well.
The oven is rated 5.3kW (max) so is 22Amps. I cannot find the manual for the hob but all the others have a 3a fuse.
I will get it checked when I get the quote for the other work.