A full desciption of the IEC cooling codes can be found in IEC document 60034-6 . IC 616 translates to what you will know as a TEAAC machine with a separate motor driven fan to circulate the external cooling air , whereas for code IC 611 the external cooling air is circulated by a shaft mounted fan.
Just to set the record straight rraqhunath, the IEC standards are all nominally based on a so called S1 , Continuously Maximum Rated duty cycle which has no provision for any continuous overload.
IEC also recognises other various intermittant/cyclic duty cycles designated S2 - S9, but none of...
