Can anybody guide me how to calculate the feeder, branch circuits(final circuits) sizes and respective protective devices as per BS or IEC standards. I am familiar with NEC/Canadian standards only. But I know the current carrying capacity tables from IEE 16th edition and european standard fuse/circuit breaker ratings etc. I do not know how they calculate feeders/branch circuits based on continuous/non continuous mor operations. If you need I can give a problem as follows.

10hp -2 motors(continuous operation)-direct online start
60 hp-1 motor(non continuos operation-less than 3 hrs) and star delta start.

Guide me how to calculate the feeder/branch circuit cables/protective devices(fuses or circuit breakers). How do you take the Service factor into account? Where do you find the locked rotor currents etc. etc. Appreciate your detailed response.