The maximum current a conductor can carry continuously without exceeding its temperature rating.
Ampacity is not a property of the conductor size alone. The same 2.5 mm² conductor carries 20 A with 60 °C insulation, 25 A with 75 °C and 30 A with 90 °C in a raceway — and different figures again in free air or bundled.
That is why a single ampacity number beside a cable size is meaningless without its basis: insulation rating, installation method, ambient temperature and how many conductors share the raceway.
Reading an ampacity table without its installation basis. The same cable has four or five legitimate ratings depending on how it is installed.
This site uses Google Analytics to count visits and see which pages are useful. It sets cookies only if you agree. See the privacy policy.