Siemens QAH 11.1

Product detailed description

Temperature sensor Siemens QAH 11.1

The Siemens QAH 11.1 sensor is used in HVAC systems to capture temperature in fan coil units. Thanks to their insulation, these sensors are especially suitable for controllers whose sensor input signals are not galvanically isolated from the 230 V ~ mains.

• Return temperature sensors
• Sensor holder for mounting on pipework 

Technical parameters: 

• Measuring range: −20...+70 °C 1)
• Measuring element: NTC (3 kΩ at 25 °C)
• Time constant in still air: 1.5 min
• Measurement accuracy at 25 °C: ±0.3 K
• Measurement type and output: passive
• Protection class: II per EN 60 730
• Weight including packaging: approx. 0.07 kg

Frequently Asked Questions

• How exactly does a manual (simple) thermostat work? It measures the temperature at its installation location, and when it drops below the set value, it closes a contact that switches on the heat source (boiler, pump, radiator) – once the set temperature is reached, the contact opens again. Unlike programmable thermostats, it has no weekly or daily schedule – the temperature is set manually using a rotary or sliding control.
• Where should the thermostat be placed? In a location that best represents the typical room temperature – away from direct sunlight, drafts, radiators, or other heat/cold sources that could distort the reading.
• Must installation be done by an electrician? Connecting the thermostat to the heating source's electrical circuit should be carried out by a person with electrical qualifications, since it involves work on the wiring and load switching.