Flex Sizes for Extension Lead

[imroberts]

I've made up a fair few extension leads in the past and have always understood the following capacities for 3 core PVC flex:

0.50mm - 3A
0.75mm - 6A
1.00mm - 10A
1.25mm - 13A
1.50mm - 16A

So for any 13A extension I've used 1.25mm or sometimes 1.50mm where the extension is particularly long.

I was looking for a couple of 4-way extensions in B&Q today and noticed that some of them, rated at 13A, come with only 1.0mm flex. I was looking at two in particular from the same brand, one of which was fitted with 1.25mm and the other with 1.0mm.

How is this the case and what is actually required?

 

[SUNRAY]

The manufacturers have discovered some loophole where undersize cable can be used, it gets worse... I purchased some 16A IEC cable fitted with 1.0mm² and despite me complaining and asking for compliant leads, supplier sent me the manufacturers documents and refused to supply anything different.

So i used them and asked for replacements when they overheated.after several such replacements they eventually supplied something different, which happened to be 2.5mm²

 

[flameport]

How is this the case and what is actually required?

They are cheap junk, designed to only be used when fully unwound and for short periods of time.

What should be used is 2.5mm² flex, but that's more expensive and doesn't fit in with the cheapomatic items that places like B&Q insist on selling.

 

[winston1]

They are cheap junk, designed to only be used when fully unwound and for short periods of time.

What should be used is 2.5mm² flex, but that's more expensive and doesn't fit in with the cheapomatic items that places like B&Q insist on selling.

Why 2.5. They are 13 amp leads not 27 amp.

 

[flameport]

2.5mm² means you can use the extension lead at full load when it's not fully unrolled.

 

[JohnW2]

2.5mm² means you can use the extension lead at full load when it's not fully unrolled.

Who said that we're talking about leads that can (sensibly) be 'rolled' or 'unrolled'. I have to say that when the OP talked of "4-way extensions in B&Q", what came into my mind were leads 1m - 4m long, occasionally longer.

Kind Regards, John