1056748 03/2023
1056748 03/2023
79
78
Protection from overheating
9.2.5 Servo actuators FLA
The motor windings of the FLA Series Actuators have an internal temperature sensor. This can be used to monitor and
protect against overheating.
Table 28
Symbol
[Unit]
11A
14A
17A
20A
Sensor
Thermistor
Input voltage
U
in
[V]
DC 5 ±5 %
Application area
T
Amb
[°C]
40 - 100
Characteristic of the measured temperature
Measured temperature [°C] = 132.9 - (Output voltage [V]) x 23.1
Fault tolerance
T
err
[K]
±6
Attention: As soon as the Hall sensors are supplied with voltage, voltage is also present at the thermistor output. When
the thermistor is not in use, the stranded wire end must be insulated.
The PTC temperature sensor used has a special characteristic curve as described in the table. It is recommended
to evaluate this sensor via an analogue input of a control unit. The assignment described above between measuring
voltage and PTC temperature is valid in the temperature measuring range from +40°C to +100°C.
Table 29
Parameter
Symbol
[Unit]
Temperature points (exemplary)
Temperature
T [°C]
40
45
50
55
60
65
70
75
80
85
90
95
100
U
[V]
4.02
3.81
3.59
3.37
3.16
2.94
2.72
2.51
2.29
2.07
1.86
1.64
1.42
The error tolerance of the PTC sensor is +/- 6 K. The tolerance of the measuring circuit must also be taken into account.
It is recommended to switch off the actuator from a winding temperature of 100°C.
Recommended switching thresholds
Table 30
Sensor type
Warning [°C]
Switch off [°C]
Thermistor
90
100
Sensor KTY in motor feedback connector
Table 26
Sensor type
Parameter
Symbol
[Unit]
Temperature points (exemplary)
KTY 84-130
Temperature
T [°C]
80
90
100
110
120
Resistance
R [Ω]
882
940
1000
1062
1127
Tolerance
[%]
+/-5%
+/-5%
+/-5%
+/-5%
+/-6%
The KTY sensor is used to measure the temperature and monitor the motor winding.
When using the KTY, it is possible to also protect the gear grease from impermissible temperatures.
The temperature sensors used in the LynxDrive Servo Actuators meet the requirements for safe isolation according to
EN 50178.
Illustration 9
0
200
400
600
800
1000
1200
1400
-30
-10
10
30
50
70
90
110
130
150
R [
Ω]
T [°C]
KKTTYY 8844--113300
The shut off temperature must be monitored in the servo controller. As with the DIN-PTC sensor, the switch off
temperature should not exceed 120 °C.
When selecting the shut off temperature, the measuring tolerance of the sensor KTY as well as the tolerance of the
measuring circuit of the servo controller must be taken into account.
Recommended switching thresholds
Table 27
Sensor type
Warning [°C]
Switch off [°C]
KTY 84-130
110
120
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Assembly Instructions Servo Actuators
