Operation
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240634 / 8146662300
2019-05-27·BA00·III·en·04
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Safety temperature monitor and limiter
Series 8146/5041-STW, 8146/5041-STB,
8146/5051-STW+STB
9
Operation
Depending on the ambient conditions, the following situations can occur during operation
Unlocking the safety temperature limiter:
Once the set limiting value has been exceeded by approx. 10%, the safety temperature
limiter can be unlocked.
16649E00
Self-monitoring for the STW safety temperature monitor and
STB safety temperature limiter
If the measuring system is destroyed, i.e., if the expansion liquid escapes,
the pressure in the membrane will drop and permanently opens the circuit of the
STW and STB. Unlocking is no longer possible for the STB.
If the sensor is cooled down into the negative temperature range (-60 °C),
the circuit opens and then closes again automatically once the temperature rises.
10
Maintenance, Overhaul, Repair
10.1 Maintenance
• Consult the relevant national regulations to determine the type and extent of
inspections.
• Adapt inspection intervals to the operating conditions.
At a minimum, check the following points during maintenance work on the device:
• Whether the clamping screws holding the cables are securely seated
• Whether the device enclosure and/or protective enclosure have cracks or other visible
signs of damage
• Compliance with the permissible temperatures (according to IEC/EN 60079)
• Whether the device is used in accordance with its intended use
