SERVICE MANUAL - BVT Partners OÜ

(3) Operation control function by the indoor controller(a) Auto operation(b)(c)'11 • SCM-SM-110If “Auto” mode is selected by the remote controller, the heating and the cooling are automatically switched according to thedifference between outdoor air temperature and setting temperature and the difference between setting temperature and returnair temperature. (When the switching of cooling mode ↔ heating mode takes place within 3 minutes, the compressor doesnot operate for 3 minutes by the control of 3-minute timer.) This will facilitate the cooling/heating switching operation inintermediate seasons and the adaptation to unmanned operation at stores, etc (ATM corner of bank).Cooling operationHeating operation-3+3Room temperature setting temperatureRoom temperature (detected with ThI-A) [deg]Note (1) Room temperature control during auto cooling/auto heating is performed according to the room temperature setting temperature. (DIFF: ±1 deg)(2) If the indoor heat exchanger temperature rises to 59°C or higher duringHeating operation stopped (cooling)heating operation, it is switched automatically to cooling operation. InHeating OKaddition, for 1 hour after this switching, the heating operation is notperformed, regardless of the temperature shown at right.5659Indoor heat exchanger temperature (°C)Operations of functional items during cooling/heatingOperation CoolingHeatingThermostat Thermostat Fan Thermostat Thermostat Hot start DehumidifyFunctional item ON OFFON OFF (Defrost)Compressor /4-way valve () Outdoor unit fan () /Indoor unit fan / / / /Louver motor// /× / /Drain pump (3) (2) (2)/ (2)Thermostat ON: Thermostat OFF: (2)Note (1) : Operation : Stop /: Turned ON/OFF by the control other than the room temperature control.(2) ON during the drain motor delay control.(3) Drain pump ON setting may be selected with the indoor unit function setting of the wired remote controller.Dehumidifying operationReturn air temperature thermistor [ThI-A (by the remote controller when the remote controller thermistor is enabled)]controls the indoor temperature environment simultaneously.1) Operation is started in the cooling mode. When the difference between the return air temperature and the settingtemperature is 2°C or less, the indoor unit fan tap is brought down by one tap. That tap is retained for 3 minutesafter changing the indoor unit fan tap.2) If the return air temperature exceeds the setting temperature by 3°C during defrosting operation, the indoor unit fantap is raised. That tap is retained for 3 minutes after changing the indoor unit fan tap.3) If the thermostat OFF is established during the above control, the indoor unit fan tap at the thermostat ON is retainedso far as the thermostat is turned OFF.4) After stopping the cooling operation, the indoor unit continues to run at Lo for 15 seconds.