Siemens 3RS2

A1/A2
init
K1
ϑ1
hyst.
11C/14NO
1 1
A1/A2
ϑ1
hyst .
K1
11C/14NO
init
1 1
DEV.MODE = TW
MON.MODE = Over
DEV.MODE = TW
MON.MODE = Under
Figure 5-1 Safety function temperature monitor
11C/14NO
11C/14NO
A1/A2
init
K1
ϑ1
hyst
A1/A2
ϑ1
hyst.
init
K1
DEV.MODE = TB/ATEX
MON.MODE = Over
DEV.MODE = TB/ATEX
MON.MODE = Under
reset
reset
1 1 1 1
Figure 5-2 Temperature limiter safety function
5.4.2 Temperature limiter TB
The temperature limiter (TB) is a device function that locks the device continuously after
tripping. If the sensor temperature overshoots or undershoots the limit by the amount of the
hysteresis, a reset is possible.
This function is only available if at least two sensors are activated and the expansion module is
therefore active. In this case the inputs for the TC sensors and the analog input 4 ... 20 mA are
deactivated.
The following settings can be speci󹪝ed:
• Monitoring for overshoot
• Monitoring for undershoot
• Hysteresis
If the relay output (K1) between the terminals 11C and 14NO is switched o󹪜 (quiescent current
principle), the device is in the safe state. This status is maintained in the valid range of the device
until manually unlocked.
A parameter change is prevented by a 3-digit code.
Digital devices
5.4 Special functions
3RS2 temperature monitoring relay
28 Equipment Manual, 02/2022, A5E42462552002A/RS-AB/002