Danfoss VLT Micro FC 51 - Special Conditions; Derating for Ambient Temperature

Minimum ambient temperature during full-scale operation 0 °C
Minimum ambient temperature at reduced performance - 10 °C
Temperature during storage/transport -25 - +65/70 °C
Maximum altitude above sea level without derating 1000 m
Maximum altitude above sea level with derating 3000 m
Derating for high altitude, see section on special conditions
Safety standards EN/IEC 61800-5-1, UL 508C
EMC standards, Emission EN 61800-3, EN 61000-6-3/4, EN 55011, IEC 61800-3
EMC standards, Immunity
EN 61800-3, EN 61000-6-1/2, EN 61000-4-2, EN 61000-4-3,
EN 61000-4-4, EN 61000-4-5, EN 61000-4-6
See section on special conditions
1.8 Special Conditions
1.8.1 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.
1.8.2 Derating for Low Air Pressure
The cooling capability of air is decreased at low air pressure.
For altitudes above 2000 m, please contact Danfoss regarding PELV.
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
1.8.3 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).
Quick Guide for VLT Micro FC 51 1 Quick Guide
MG.02.B5.02 - VLT
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