System Integration; Ambient Operating Conditions; Humidity; Temperature - Danfoss VLT AutomationDrive FC 301 Series Design Manual

System Integration

5 System Integration

5.1 Ambient Operating Conditions

5.1.1 Humidity

Although the adjustable frequency drive can operate
properly at high humidity (up to 95% relative humidity),
condensation must always be avoided. There is a specific
risk of condensation when the adjustable frequency drive
is colder than moist ambient air. Moisture in the air can
also condense on the electronic components and cause
short circuits. Condensation occurs to units without power.
It is advisable to install a cabinet heater when conden-
sation is possible due to ambient conditions. Avoid
installation in areas subject to frost.
Alternatively, operating the adjustable frequency drive in
stand-by mode (with the unit connected to line power)
reduces the risk of condensation. However, ensure the
power dissipation is sufficient to keep the adjustable
frequency drive circuitry free of moisture.

5.1.2 Temperature

Minimum and maximum ambient temperature limits are
specified for all adjustable frequency drives. Avoiding
extreme ambient temperatures prolongs the life of the
equipment and maximizes overall system reliability. Follow
the recommendations listed for maximum performance
and equipment longevity.
•
Although drives can operate at temperatures
down to 14°F [-10°C], proper operation at rated
load is only guaranteed at 32°F [0°C] or higher.
•
Do not exceed the maximum temperature limit.
•
The lifetime of electronic components decreases
by 50% for every 17°F [10°C] when operated
above its design temperature.
•
Even devices with IP54, IP55, or IP66 protection
ratings must adhere to the specified ambient
temperature ranges.
•
Additional air conditioning of the cabinet or
installation site may be required.
MG33BF22
Design Guide

5.1.3 Temperature and Cooling

The adjustable frequency drives have built-in fans to
ensure optimum cooling. The main fan forces the air flow
along the cooling fins on the heatsink, ensuring a cooling
of the internal air. Some power sizes have a small
secondary fan close to the control card, ensuring that the
internal air is circulated to avoid hot spots. The main fan is
controlled by the internal temperature in the adjustable
frequency drive and the speed gradually increases along
with temperature, reducing noise and energy consumption
when the need is low, and ensuring maximum cooling
when the need is there. The fan control can be adapted
via 14-52 Fan Control to accommodate any application, also
to protect against negative effects of cooling in very cold
climates. In case of overtemperature inside the adjustable
frequency drive, it derates the switching frequency and
pattern, see chapter 5.1.4 Manual Derating for more info.
Minimum and maximum ambient temperature limits are
specified for all adjustable frequency drives. Avoiding
extreme ambient temperatures prolongs the life of the
equipment and maximizes overall system reliability. Follow
the recommendations listed for maximum performance
and equipment longevity.
•
•
•
•
•
Rev. 2014-04-04 All rights reserved.
Although adjustable frequency drives can operate
at temperatures down to 14°F [-10°C], proper
operation at rated load is only guaranteed at 32°F
[0°C] or higher.
Do not exceed the maximum temperature limit.
Do not exceed the maximum 24-hour average
temperature.
(The 24-hour average temperature is the max.
ambient temperature minus 9°F [5°C].
Example: Max. temperature is 122°F [50°C],
maximum 24-hour avg. temperature is 113°F
[45°C]).
Observe the minimum top and bottom clearance
requirements (chapter 8.2.1.1 Clearance).
As a rule of thumb, the lifetime of electronic
components decreases by 50% for every 17°F
[10°C] when operated above its design
temperature.
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