GE Industrial Solutions AF-60 LP Micro Drive Operating Instructions - Manual (Page 66)

8.3 Special Conditions
8.3.1 The Purpose of Derating
Derating must be taken into account when using the frequency converter at low air pressure (heights), at low speeds or at high ambient temperature. The required
action is described in this section.
8.3.2 Derating for Ambient Temperature
The ambient temperature measured over 24 hours should be at least 5 °C lower than the max. ambient temperature.
If the frequency converter is operated at high ambient temperature, the continuous output current should be decreased.
The frequency converter has been designed for operation at max 50 °C ambient temperature with one motor size smaller than nominal. Continuous operation
at full load at 50 °C ambient temperature will reduce the lifetime of the frequency converter.
8.3.3 Derating for Low Air Pressure
The cooling capability of air is decreased at low air pressure.
For altitudes above 2000 m, please contact GE .
Below 1000 m altitude no de-rating is necessary but above 1000 m the ambient temperature or the maximum output current should be decreased.
Decrease the output by 1% per 100 m altitude above 1000 m or reduce the max. ambient temperature by 1 degree per 200 m
8.3.4 Derating for Running at Low Speeds
When a motor is connected to at frequency converter, it is necessary to check that the cooling of the motor is adequate.
A problem may occur at low speeds in constant torque applications. Running continuously at low speeds – below half the nominal motor speed – may require
additional air cooling. Alternatively, choose a larger motor (one size up).
AF-60 LP™ Micro Drive Operating Instructions
DET-579A
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