User's Manual

Technical specifications
8.6 Thermistor motor protection
M200D AS-Interface Basic
Manual, 03/2009, A5E01668085-01
93
8.6 Thermistor motor protection
Temperature sensor PTC Thermoclick
Evaluation characteristic to IEC 60947-8 Type A —
Summation cold resistance sensor circuit < 1.5 kΩ
No-load voltage of sensor circuit < 30 V
Short-circuit current sensor circuit < 1.2 mA
Trip level 3.4 … 3.8 kΩ
Reset level 1.5 … 1.65 kΩ
Short-circuit detection < 30 Ω No
Electrical isolation vis-à-vis Main circuit
U
AS-i
U
PWR
Yes (U
i
= 400 V)
Yes (U
i
= 400 V)
Yes (U
i
= 400 V)
8.7 Switching frequency
If motors are switched too often, this causes the thermal motor model to respond.
The maximum permissible switching frequency depends on the following operating data:
Direct and reversing starters, electronic (sDSte / sRSte) up to 4 kW
3RK1315-5KS71-.AA. (0.15 A to 2 A)
Class 10
Device setup Vertical Horizontal
Rated current I
e
2 A 2 A 2 A 2 A 2 A 2 A
Ambient temperature 40 °C 50 °C 55 °C 40 °C 50 °C 55 °C
Degree of protection
1) 2) 1) 2) 1) 2) 1) 2) 1) 2) 1) 2)
Direct start ED=30 %
(8xI
e
) / 0.4 s
150 1000 150 1000 150 1000 150 1000 150 1000 150 1000
ED=70 % (8xI
e
) / 0.4 s 90 500 90 500 90 500 90 500 90 500 90 500
ED=30 % (8xI
e
) / 0.8 s 75 490 75 490 75 490 75 490 75 490 75 490
ED=70 % (8xI
e
) / 0.8 s 45 250 45 250 45 250 45 250 45 250 45 250
1) Duty cycle current rms value = 1.15 x I
e
→ motor protection
2) Duty cycle limit for motor starter. The motor should be protected against overload here by means of a thermistor.