Danfoss EPS VLT, Quick Reference Manual

Page: 11 / 17

Using a digital input and 24V 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 Thermistor Trip [2]
Set 1-93 Thermistor Source to Digital Input 33 [6]
PTC / Thermistor
OFF
ON
+24V
12 13 18 37 32
A
27 19 29 33
B
20
GND
R <6.6 k Ω >10.8 k Ω
130BA151.11
Using a digital input and 10V 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
Thermistor Trip
[2]
Set
1-93 Thermistor Source
to
Digital Input 33
[6]
PTC / Thermistor
R
OFF
ON
<800 Ω
+10V
130BA152.10
>2.7 kΩ
12 13 18 37 32 27 19 29 33 20
55 50 39 42 53 54
Using an analog input and 10V 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 Thermistor Trip [2]
Set 1-93 Thermistor Source to Analog Input 54 [2]
Do not select a reference source.
55 50 39 42 53 54
R <3.0 k Ω
>3.0 k Ω
+10V
130BA153.11
PTC / Thermistor
OFF
ON
Input
Digital/analog Supply Voltage V
Cut-out Values Threshold
Cut-out Values
Digital 24 < 6.6k
Ω
- > 10.8k
Ω
Digital 10
< 800
Ω
- > 2.7k
Ω
Analog 10
< 3.0k
Ω
- > 3.0k
Ω
NOTE
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 in order to prevent over
heating. 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 .
VLT
®
HVAC Drive Quick Reference Guide