Natural cooling.
a. Air natural cooling (Dry type).
b. Oil immersed natural cooling.
c. Oil immersed, forced oil circulation with natural cooling.
Artificial cooling.
a. Oil immersed forced air circulation with air blast cooling.
b. Oil immersed blast cooling.
c. Air blast cooling.
Artificial cooling (water).
a. Oil immersed water cooling.
b. Oil immersed forced oil circulation with water cooling.
Mixed cooling (water).
This is the method of cooling combining oil natural, water, air natural, air blast and forced oil.
