Danfoss VLT AutomationDrive FC 301 Programming Manual page 55

Parameter Descriptions
1-90 Motor Thermal Protection
Option: Function:
[8] ETR trip 3
[9] ETR
warning 4
[10] ETR trip 4
NOTICE
If [20] ATEX ETR is selected, follow the instructions in the
dedicated chapter of the design guide and the
instructions provided by the motor manufacturer.
NOTICE
If [20] ATEX ETR is selected, set parameter 4-18 Current
Limit to 150%.
3.2.13 PTC Thermistor Connection
R
(Ω)
4000
3000
1330
550
250
-20 °C  nominal -5 °C
Illustration 3.12 PTC Profile
Using a digital input and 10 V as supply:
Example: The frequency converter trips when the motor
temperature is too high.
Parameter set-up:
•
Set parameter 1-90 Motor Thermal Protection to [2]
Thermistor Trip.
•
Set parameter 1-93 Thermistor Source to [6] Digital
Input.
MG33MO02
Programming Guide
 [°C]
 nominal +5 °C
 nominal
Danfoss A/S © 01/2018 All rights reserved.
39 42 50 53 54 55
12 13 18 19 27 29 32 33 20 37
PTC / Thermistor
Illustration 3.13 PTC Thermistor Connection - Digital Input
Using an analog input and 10 V as supply:
Example: The frequency converter trips when the motor
temperature is too high.
Parameter set-up:
•
Set parameter 1-90 Motor Thermal Protection to [2]
Thermistor Trip.
•
Set parameter 1-93 Thermistor Source to [2] Analog
Input 54.
39 42 50 53 54 55
PTC / Thermistor
Illustration 3.14 PTC Thermistor Connection - Analog Input
Input Supply voltage
digital/analog
Digital 10 V
Analog 10 V
Table 3.8 Threshold Cutout Values
NOTICE
Check that the selected supply voltage follows the
specification of the used thermistor element.
OFF
ON
R
<800 Ω >2.7 kΩ
OFF
ON
<3.0 k Ω
R
>3.0 k Ω
Threshold
cutout values
<800 Ω⇒2.7 kΩ
<3.0 kΩ⇒3.0 kΩ
53
3 3