Using lugs for termination

[jim dungar]

More or less midway between a 12 and 10 gauge

But the question is; Are the lugs of a breaker, designed to IEC standards, capable of directly accepting this type of conductor, or is a ferrule required?

 

[tortuga]

Is it mandatory to use lugs for termination of building wires in circuit breakers or can directly connect wire to the circuit breaker

What type of breaker is it? UL-489, IEC 60898-1, 60947-2 or ?

Then may I suggest a forum which deals with more international engineering questions rather than one dedicated to the NEC and North American systems?
You could try eng-tips.com

IEC 60898-1 DIN rail breakers are used here they are often dual listed under UL-489, you can find them generally from manufacturers such as Siemens, ABB, Schneider, Eaton etc.
They typically allow stranded wire as mentioned above.
IEC 60898-1 breakers show nominal current is combined with the curve (for example 20 A breaker of C curve is marked C20).
Fault current breaking capacity is marked in Amperes in a rectangle e.g. 6000

IEC 60947-2 breakers are application specific so if the breakers is identified as on the side as a IEC 60947-2 or has the fault current capacity marked in kA, you need to consult the manufacturers documentation included in the self certification (CE) for the types and sizes of stranded wire allowed.

 

[Joethemechanic]

But the question is; Are the lugs of a breaker, designed to IEC standards, capable of directly accepting this type of conductor, or is a ferrule required?

Personally I'd read the manufacturer's documentation