Rating of Flexible cable

[SUNRAY]

I've just received this reply to an enquiry with a well known electronic/electrical supplier:


Further to your error report for the IEC Male C20 to Female C19 Extension Lead.

After checking, the lead is certified at 16A with 1.0mm2 cable. This range of cables has 1.0mm2 cable for lengths of 2m or less, with 1.5mm2 cable for lengths above 2m.

Should I be feeling concerned about using them to supply power to a 3.6KW load?

 

[blup]

If it's an extension lead I would personally use 1.5mm minimum, although the current would decrease with cable length.

Blup

 

[SUNRAY]

If it's an extension lead I would personally use 1.5mm minimum, although the current would decrease with cable length.

Blup

Yeah
These are extention leads with moulded 16A connectors.

 

[plugwash]

I'm pretty sure there is a rule in some IEC standard that says 0.75mm² is nominally rated at 6A, but this can be increased to 10A for short leads. I would not be surprised if there was a similar rule for 1.0mm².

I presume the thinking is that a short lead is less likely to be subject to grouping/coiling/enclosure, so they can use a rating methodology closer to what BS7671 would desribe as "free air".

 

[JohnD]

Should I be feeling concerned about using them to supply power to a 3.6KW load?

What sort of machine is it?

 

[SUNRAY]

What sort of machine is it?

flood lighting...

3 channels of 2x 600W

 

[mattylad]

It's gonna get warm.....

 

[JohnD]

flood lighting...

3 channels of 2x 600W

That's a vast number of LEDs.

 

[blup]

Yeah
These are extention leads with moulded 16A connectors.

It would be sensible to use the leads that come in 1.5mm, those on Amazon quote 10A for 1.0mm cable, 16A for 1.5mm, so maybe an error on your suppliers part

Blup

 

[securespark]

I had issues with appliance flexes of 0.75 being fitted with 13A fuses, but it seems to be the norm now.

I thought the ''kettle'' connectors were rated at 10A?

 

[Robin0577]

C19/20 aren't kettle connectors, they're significantly bigger and the pins are at 90 degrees to those on the smaller version.

 

[Risteard]

I had issues with appliance flexes of 0.75 being fitted with 13A fuses, but it seems to be the norm now.

It's perfectly acceptable under BS 1363 so long as the length is not greater than 2m and it is fitted with a moulded plug.

 

[SUNRAY]

It's perfectly acceptable under BS 1363 so long as the length is not greater than 2m and it is fitted with a moulded plug.

I believed it to be 700mm from PAT days.

 

[SUNRAY]

It would be sensible to use the leads that come in 1.5mm, those on Amazon quote 10A for 1.0mm cable, 16A for 1.5mm, so maybe an error on your suppliers part

Blup

That's why I enquired, as the paper catalogue states 1.5mm² for the whole range of lengths and manufacturers docs in the site state 1.5mm². However the on line catalogue lists variously as 1.0 or 1.5mm².
From their reply it looks fairly explicit.

 

[JohnW2]

It's gonna get warm.....

It's not too easy to understand (at least, not for me!) what the CCC tables in BS7671 are implying in relation to the 'operating temp' of flexible cables.

For everything other than 'flexible cables' they give CCCs for cables of a given 'temperature rating' (usually 70°C or 90°C) and people seem to assume that this means that this is the temperature that will be approached when (with the installation method concerned) a current equal to the CCC flows continuously.

However, for 'flexible cables', Table 4F3A gives just a single CCC for each cable CSA, but the footnotes relating to 'rating factors' for various ambient temperatures seem to imply that the table relates to 60°-, 90°-, 110°- and 150°-rated cables.

Kind Regards, John