Specifications

Set 1-93 Thermistor Source to [6] Digital Input 33
PTC / Thermistor
R
OFF
ON
<800 Ω
+10V
130BA152.10
>2.7 kΩ
12 13 18 37322719 29 33 20
5550
39 42 53 54
Illustration 2.43 Using a Digital Input and 10 V as Power
Supply
Using an analog input and 10 V as power supply:
Example: The frequency converter trips when the motor
temperature is too high.
Parameter set-up:
Set 1-90 Motor Thermal Protection to [2] Thermistor Trip
Set 1-93 Thermistor Source to [2] Analog Input 54
Do not select a reference source.
555039 42 53 54
R
<3.0 k Ω
>3.0 k Ω
+10V
130BA153.11
PTC / Thermistor
OFF
ON
Illustration 2.44 Using an Analog Input and 10 V as Power
Supply
Input
Digital/analog
Supply Voltage
V
Cut-out Values
Threshold
Cut-out Values
Digital 24
< 6.6 kΩ - > 10.8 kΩ
Digital 10
< 800 Ω - > 2.7 kΩ
Analog 10
< 3.0 kΩ - > 3.0 kΩ
Table 2.26 Threshold Cut-out Values
NOTICE
Check that the chosen supply voltage follows the specifi-
cation of the used thermistor element.
Summary
With the torque limit feature the motor is protected for
being overloaded independent of the speed. With the ETR,
the motor is protected for being over heated and there is
no need for any further motor protection. That means
when the motor is heated up, the ETR timer controls for
how long time the motor can be running at the high
temperature, before it is stopped to prevent overheating. If
the motor is overloaded without reaching the temperature
where the ETR shuts of the motor, the torque limit is
protecting the motor and application for being overloaded.
ETR is activated in 1-90 Motor Thermal Protection and is
controlled in 4-16 Torque Limit Motor Mode. The time
before the torque limit warning trips the frequency
converter is set in 14-25 Trip Delay at Torque Limit.
Introduction to VLT® HVAC D... Design Guide
MG11BC02 Danfoss A/S © Rev. 06/2014 All rights reserved. 51
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