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

Usage

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

The RAB thermostat can be used in combination with zone valves, fans or thermal valves.

Functions

Heating - if the room temperature falls below the selected setpoint, the thermostat’s heating contact will close.

Cooling - if the room temperature exceeds the selected setpoint, the thermostat’s cooling contact will close. 

Switching between heating/cooling - if there is a requirement for automatic switching of heating/cooling modes, this can be done externally (eg. by an additional 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, it is necessary to change the position of the jumpers on the thermostat printed circuit board before commissioning.