Thermistor; Ambient Conditions; Humidity; Temperature - Danfoss VLT DriveMotor FCP 106 Design Manual

System Integration

3.5.6.2 Thermistor

The thermistor is positioned between motor windings. The
connection for the thermistor is placed in the motor plug
at terminal positions T1 and T2. For terminal positions and
3 3
wiring details, refer to the section Motor Connection in VLT
DriveMotor FCP 106 Operating Guide.
To monitor the thermistor, set parameter 1-90 Motor
Thermal Protection to [1] Thermistor Warning or [2]
Thermistor Trip.
R
(Ω)
4000
3000
1330
550
250
-20 °C
Illustration 3.10 Typical Thermistor Behavior
When the motor temperature increases the thermistor
value above 2.9 kΩ, the drive trips. When the thermistor
value decreases below 0.8 kΩ, the drive restarts.
OFF
ON
Illustration 3.11 Drive Operation with Thermistor
NOTICE
Select the thermistor according to the specification in
Illustration 3.10 and Illustration 3.11.
34
VLT
 nominal -5 °C  nominal +5 °C
 nominal
<800 Ω >2.9 kΩ
Danfoss A/S © 12/2018 All rights reserved.
®
DriveMotor FCP 106
NOTICE
If the thermistor is not galvanically isolated,
interchanging the thermistor wires with the motor wires
may permanently damage the drive.
®
A mechanical thermal switch (Klixon type) can be used
instead of a thermistor.

3.6 Ambient Conditions

3.6.1 Humidity

Although the 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 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. Install a cabinet heater when condensation is
possible due to ambient conditions.
Operating the drive in stand-by mode (with the unit
connected to the mains) reduces the risk of condensation.
However, ensure that the power dissipation is sufficient to
keep the drive circuitry free of moisture.
The drive complies with the following standards:
 [°C]
•
IEC/EN 60068-2-3, EN 50178 9.4.2.2 at 50 °C
(122 °F).
•
IEC 600721 class 3K4.

3.6.2 Temperature

Minimum and maximum ambient temperature limits are
specified for all drives. Avoiding extreme ambient temper-
atures 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 -10 °C (14 °F), proper operation at rated
load is only guaranteed at 0 °C (32 °F) or higher.
•
Do not exceed the maximum temperature limit.
•
The lifetime of electronic components decreases
by 50% for every 10 °C (50 °F) when operated
R
above its design temperature.
•
Even devices with IP54, IP55, or IP66 protection
ratings must adhere to the specified ambient
temperature ranges.
•
Extra air conditioning of the cabinet or instal-
lation site may be required.
MG03M302