Siemens 3RS2

• INPUT: Temperature measuring input (active)
– T1 (default setting)
– EX.UNIT → on/o󹪜 → ON = 1T. → 2T. → 3T. → 1T. + 2T. → 1T. + 3T. → 2T. + 3T. → 1T. + 2T.
+ 3T. → 4 ... 20 mA
– T1 is the sensor input of the 󹪝rst temperature sensor on the 3RS26/28 with the terminal
markings "T1/T-", "T2/T+" and "T3".
– T2 is the sensor input of the second temperature sensor on the 3RS26/28 with the
terminal markings "2T1", "2T2" and "2T3".
– T3 is the sensor input of the second temperature sensor on the 3RS26/28 with the
terminal markings "3T1", "3T2" und "3T3".
– The active temperature measuring inputs T1, T2 and T3 can be activated/deactivated in
any combination if the 4 mA ... 20 mA input is deactivated. If the 4 mA ... 20 mA input is
activated, you cannot activate any other inputs. The ATEX mode supports only the
4 mA ... 20 mA temperature measuring input.
– Ex.Unit: Activation/deactivation of the sensor expansion module
• SENSOR:
Sensor type selection: Only sensors of the same type can be selected; for the sensor
expansion module, these are resistance sensors.
– Resistance sensors: Pt100 (default setting), Pt1000, NTC, KTY83, KTY84, each 2-wire / 3-
wire
– Thermocouples: Types J, K, T, R, S, E, B, N
– Temperature measuring input 4 mA ... 20 mA
• MON.MODE: Monitoring mode
– Over: Temperature overshoot (default setting)
– Under: Temperature undershoot
– Window: Temperature range monitoring / window monitoring ("Standard" operating
mode only)
• MEMORY: The memory function saves the device status before the supply voltage fails. If the
memory function is selected ("on"), the device returns to the state that is was in before the
supply voltage was lost after the power is restored. With activated memory function, the
setting option Autoreset (AutoRST) is deactivated. With deactivated memory function, the
setting option Autoreset (AutoRST) is activated.
– on (default setting)
– o󹪜
• AUTO RST: The automatic reset function activates or deactivates automatic reset of the
device when the selected temperature limit is overshot/undershot.
– on
– o󹪜 (default setting)
Digital devices
5.10 Operator control
3RS2 temperature monitoring relay
Equipment Manual, 02/2022, A5E42462552002A/RS-AB/002 41