IC Rating

The cooling methods are designated by the letters IC (International Cooling) and two characteristic numerals.
The first numeral signifies the cooling circuit arrangement and the second the method of supplying power to circulate the coolant.
All machines covered by this simplified code are air cooled. Refer IEC 60034-6 (Rotating Electric Machines, Part 6: Methods of Cooling) for details.

First digit	Description
0	Free circulation
1	Inlet duct ventilated One inlet duct
2	Outlet duct ventilated One outlet duct
3	Inlet and outlet duct ventilated
4	Frame surface-cooled Machine (coolant is airflow)
5	Integral heat exchanger (coolant is airflow)
6	Machine mounted heat exchanger (coolant is airflow)
7	Integral mounted heat exchanger (coolant is not airflow)
8	Machine mounted heat exchanger (coolant is not airflow)
9	Machine with separate mounted heat exchanger

Second Digit	Description
0	Free convection
1	Self-circulation
2	Integral component Mounted on seperate shaft
3	Dependent component Mounted on the machine
5	Integral independent component
6	Independent component Mounted on the machine
7	Independent and separate device or cooling system
8	Relative displacement e. g. through airflow

Example IC 41

4.:
Frame surface-cooled Machine (coolant is airflow)

.1:
Self-circulation