JUMO 701150 14597 safetyM STB/STW - Safety Temperature Limiter and Safety Temperature Monitor Operating Manual - Manual (Page 46)

6 Safety Manual 2014-05-01 46
6.9.2 Safety-relevant system properties
Device versions differ in the following architectures:
The evaluation unit from 701150 in STW, STB versions is implemented as 1oo2D architecture.
The types with an individual sensor are executed in one-channel sensor systems (1oo1).
The variants with two sensors are consistently structured with two channels.
The two subsystems have to be galvanically isolated from each other.
Systems have a lifetime of ten years.
The proof check for SIL2 and SIL3 certified systems is also ten years.
If the temperature is above/below the permissible limits, the system switches to the safe state without delay. Premature switch-
ing is admissible if a malfunction is detected.
These are monitored:
-
Probe break in the sensor system subsystem
- Probe short circuit in the sensor system subsystem
- Random hardware failure in one channel
These are monitored:
-
Probe break sensor system subsystem
- Probe short circuit in the sensor system subsystem
- Reverse polarity of the probes
- Random hardware failure in one channel