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

Application

Regulation of room temperature in heating or cooling systems. Examples include use in commercial and residential buildings or in light industrial operations.

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

Function

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

Cooling - when the temperature exceeds the set limit, the cooling output contact is activated.

Switching heating/cooling - if there is a requirement for automatic mode switching between heating and cooling, this can be done externally (e.g., with an auxiliary thermostat).

Speed Control

Manually - one of the three speeds is set via the switch. In this case, the fan runs continuously.
Automatically - the fan starts when the thermostat is activated. In this case, it is necessary to change the jumper position on the thermostat's circuit board before commissioning.