Flue gas thermostat JUMO type STM-RW-2

Inspected to TÜV standards according to DIN 3440, Protection type IP 54
• For monitoring flue gas temperature in solid fuel boilers during bivalent operation with oil heating boilers
• Works according to the principle of rod expansion
• The immersion pipe and metal rod arranged in it have different expansion coefficients so that a length differential is set between them that is dependent on temperature
• Using a gear ration mechanism, they affect a micro switch that is operated above a set limit value temperature
• The micro switch is reset after the immersion pipe has cooled down to approx. 10-30 K
In the event of an immersion pipe break, the circuit remains open
• STM-RW-2 and STM-RW-2/OS
• STM: Rod thermostat with micro switch
• RW: Flue gas temperature monitor (ATW) with changeover contact
• with inset scale
• Immersion tube length: 150 mm
• Housing: Die-cast aluminium, with sealable screws
• Connection: DN 15 (G 1/2“), steel
• Target value setting: can be set on the target value spindle via the internal scale.
• Switching element model STM-RW-2: 1-pin micro switch with switch-over contact
• Switching element model STM-RW-2/OS: Micro switch with 2 separate circuits, 1 x NO contact, 1 x NC contact
• Position of use - can be used any way
• Protection type: IP 54
• Limit value range: +40°C to +120°C set at +100°C ex-factory
• Accuracy of switching point: 0 to- +10 K
• Max. switching capacity: AC 10 (2) A, 250 V, cos. = 1 (0.6) , DC 0.25 A, 250 V
• Switching differential: STM-RW-2: 10-18 K, STM-RW-2/OS: 10-30 K
• Time constant: Flue gas: approx. 45 sec. of intermediate influence on the ambient temperature
• Switching point offset based on the deviation: from + 22°C ~ 0.07 K/K
• Last ambient temperature on the sensor: + 700°C
• Last ambient temperature on the switching head: + 80°C
• Last storage temperature: max. +80°C, min. -50°C
OS: like STM-2/RW with micro switch with 2 separate circuits, 1 x NO contact, 1 x NC contact