30 Rockwell Automation Publication 1560F-UM001A-EN-P - June 2019
Chapter 1 Product Overview
Thermistor/PTC Protection
The optional 150-SM2 module lets the SMC-50 control module interface with
motor PTC sensors. It is common for motor manufacturers to embed PTC
thermistor sensors in motor stator windings to provide temperature monitoring
of the motor windings. Because PTC thermistor sensors react to the actual motor
winding temperature, enhanced motor protection can be provided to address
conditions like obstructed motor cooling and high ambient temperature. Table 1
defines the required PTC thermistor input and response ratings for operation
with the 150-SM2 module.
Table 1 - PTC Thermistor Input & Response Ratings
Figure 17 shows the required PTC sensor characteristics for operation with the
150-SM2 Option Module, per IEC-34-11-2.
Figure 17 - PTC Sensor Characteristics per IEC-34-11-2
Thermistor Input Response Ratings
Response Resistance: 3400 Ω ± 150 Ω
Reset Resistance: 1600 Ω ± 100 Ω
Short-circuit Trip Resistance: 25 Ω ± 10 Ω
Maximum Voltage at PTC Terminals: (RPTC = 4 K ohms): < 7.5V
Maximum Voltage at PTC Terminals: (RPTC = open): 30V
Maximum Number of Sensors Connected in Series: 6
Maximum Cold Resistance of PTC Sensor Chain: 1500 Ω
Response Time: 800 ms
1330
550
250
100
20
10
-20 °C
0 °C
TNF -20K
TNF -5K
TNF
TNF +20K
TNF +5K
4000
To Next Page
Loading...
