Special Conditions; Derating For Ambient Temperature And Switching Frequency; Derating For Low Air Pressure - Danfoss VLT Series Quick Manual

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Quick Guide VLT HVAC Basic Drive Cascade Controller Quick Guide
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Derating for high altitude, see 1.9 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
EN 61800-3, EN 61000-3-12, EN 61000-6-1/2, EN 61000-4-2, EN 61000-4-3, EN 61000-4-4, EN
EMC standards, Immunity 61000-4-5, EN 61000-4-6

1.9 Special Conditions

1.9.1 Derating for Ambient Temperature
and Switching Frequency
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
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decreased. For derating curve, see VLT HVAC Basic Design
Guide.

1.9.2 Derating for Low Air Pressure

The cooling capability of air is decreased at low air
pressure. For altitudes above 2000 m, 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° per 200
m.
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34 MG18F402 - VLT is a registered Danfoss trademark