Danfoss VLT Refrigeration Drive FC 103 Programming Manual page 53

Parameter Description
3.3.12.1 PTC Thermistor Connection
R
(Ω)
4000
3000
1330
550
250
-20 °C  nominal -5 °C
Illustration 3.11 PTC Profile
Example using a digital input and 10 V as supply
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.
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PTC / Thermistor
Illustration 3.12 PTC Thermistor Connection - Digital Input
Example using an analog input and 10 V as supply
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.
MG16H202
Programming Guide
 [°C]
 nominal +5 °C
 nominal
OFF
ON
R
<800 Ω >2.7 kΩ
Danfoss A/S © 05/2016 All rights reserved.
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PTC / Thermistor
Illustration 3.13 PTC Thermistor Connection - Analog Input
Input Supply voltage
digital/analog [V]
Digital 10
Analog 10
Table 3.7 Threshold Cutout Values
NOTICE
Check that the selected supply voltage follows the
specification of the used thermistor element.
3.3.12.2 ETR
The calculations estimate the need for a lower load at
lower speed due to less cooling from the fan incorporated
in the motor.
t [s]
2000
1000
600
500
400
300
200
100
60
50
40
30
20
10
1.0 1.2 1.4 1.6 1.8
Illustration 3.14 ETR Profile
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
f OUT = 1 x f M,N (par. 1-23)
f OUT = 2 x f M,N
f OUT = 0. 2 x f M,N
I
M
I (par. 1-24)
2.0
MN
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