The KTRRB-117.128 climate controller was specially developed for controlling fan coil units, fan coil devices and other fan-assisted air conditioning systems in 2- or 4-pipe systems with normally closed valves. The KTRRB-117.128 is used as a single room temperature controller with an internal sensor or as an external control device with an optional remote sensor. The optional external flow sensor is used to automatically switch the controller to heating or cooling mode in 2-pipe operation depending on the flow temperature; alternatively, this input can be used as a H/K switchover contact. If the sensor breaks or there is a sensor short circuit, the heating is controlled with a duty cycle of 30% to prevent cooling or frost damage in the room. With an internal switch, the existing contact input can be configured as an ECO contact or standby contact. ECO function: If this function is selected, the temperature is regulated to a temperature 3K lower in heating mode and 3K higher in cooling mode. Standby function: If this function is selected, the controller is switched off (frost protection remains active). Surface / wall mounting or using an adapter plate on a flush-mounted box.
