The open cooling system turns on a refrigeration circuit where the external ambient air enters the machine Gates AX22 and passes through the hot parts, removing the heat that returns to the environment. In this system the machine is called open and due to this fact can only be used in environments not contaminated, that is, in environments whose atmosphere has no agents capable of attacking the insulation of the electric motor. In the open system we can also have fans mounted on the shaft, and then a self-ventilated machine, or with independent ventilation, when the fans are driven independently from the machine shaft.
When the environment at the machine is contaminated, the air in the machine can be drawn through a duct that draws air from another uncontaminated area. This cooling system is known as IC 33. According to the IEC standard, when the machine offers one or two internal fans and mounted on the shaft, the cooling system is called the IC-01. When the fan is activated independent of the axis of the machine, the cooling system is designated IC 06.