Tap Conductor rules in IEC standards

[PaulBr]

In USA per NEC (National Electric Code) definition:
Tap conductor is Conductor with an upstream overcurrent protection whose rating exceeds the maximum
ampacity of the conductor.
NEC has some rules that limit length and ampacity of tap conductors.
Are Tap Conductor rules unique to NEC or there are some similar rules in IEC standard?
If there is industrial electrical panel with main circuit breaker and several motor circuits with motor circuit protectors. How to determine minimum size of conductor between main circuit breaker and motor circuit protector?
NEC permits minimum ampacity of this conductor to be 0.1 of main circuit breaker. How it is done in IEC world.

Thank you,

PaulBr.

 

[JezNZ]

I am not sure exactly for IEC world, but our rules are derived from BS and IEC basis.

As long as a conductor is protected from short-circuit, there is an exception from overload protection where it is performed by the downstream device.