AJJewsbury:
There's a formula relating the derating of a cable to its conductor temperature (I don't have it to hand but should be able to dig it out if needs be) - from memory it's similar to the one for adjusting voltage drop when a cable isn't fully loaded. I'm sure I've seen it used to justify the use of 1.5mm² MICC cable on ring circuits in one of the IET books - showing that the 70 degree terminal temperature isn't exceeded.
AJJewsbury:
There's a formula relating the derating of a cable to its conductor temperature (I don't have it to hand but should be able to dig it out if needs be) - from memory it's similar to the one for adjusting voltage drop when a cable isn't fully loaded. I'm sure I've seen it used to justify the use of 1.5mm² MICC cable on ring circuits in one of the IET books - showing that the 70 degree terminal temperature isn't exceeded.
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