Manual for Induction Motors and Generators
88 -
Maintenance
3BFP 000 050 R0101 REV E
Figure 7-10 Cooling air flow (typical asymmetric construction)
The machine can be equipped with temperature detector(s) for monitoring the internal cooling
air. If the temperature detectors show normal temperature, no additional maintenance to the
supervision inspection is usually required for the cooling system.
If the temperature detectors show abnormal temperature or close to the alarm level in winding
or in cooling air, the cooling system has to be checked. If the coolers have to be cleaned, see the
instructions below.
7.8.3.2 Cleaning
Some fouling of the cooling surface and the tube wall will eventually occur. This fouling
reduces the cooling capacity. The heat exchanger should therefore be cleaned at regular
intervals, to be determined from case to case, depending of the properties of the cooling air.
During the initial period of operation, the heat exchanger should be inspected frequently.
Blow the heat exchanger clean with compressed air or clean it with a suitable brush. Do not use
a steel brush in aluminium tubes as it can damage the tubes; a soft round brass wire brush can be
used instead.
7.8.4 Maintenance of external blower motors
The external blower motors are maintenance free units, e.g. the bearings of external blower
motors are greased for life. A spare external blower motor is recommended. The maintenance of
the blower motor is performed according to the motor's manual.
