Room thermostat for controlling two-pipe fan-coil units. The RAB 21 thermostat is equipped with a manual heating / cooling switch and a 3-stage fan speed switch.

Use

Room temperature control in heating or cooling systems. An example is use in commercial and residential buildings or in light industrial plants.

The RAB thermostat is suitable for use in combination with zone valves , fans or with valves with thermoelectric actuators .

Function

Heating - when the temperature drops below the set value, the heating output contact closes.

Cooling - when the set value is exceeded above the set limit, the cooling output contact closes.

Heating / cooling switching - if there is a requirement for automatic switching of heating / cooling modes, this can be done externally (eg by an attached thermostat).

Speed control

Manual - one of three speeds is set via the switch. In this case, the fan runs continuously.
Automatic - the fan starts when the thermostat is switched on. In this case of control, it is necessary to change the position of the jumper on the thermostat PCB before commissioning.