Daikin VRV III REYQ8PY1B, Service Manual

Page: 154 / 472

SiBE37-701 Outline of Control (Indoor Unit)
Function 143
6.2.2 Thermostat Control while in Normal Operation
VRV multi systems are set at factory to thermostat control mode using the remote controller.
While in normal thermostat differential control mode (i.e., factory set mode), the thermostat
turns OFF when the system reaches a temperature of -1°C from the set temperature while in
cooling operation or of +1°C from that while in heating operation.
While in a single remote controller group control, the body thermostat is only used for this
control.
Furthermore, while in heating operation, cassette-mounted indoor units conduct the thermostat
control by a value compensated by -2°C for the value detected with the body thermostat.
(Through field settings, the thermostat differential setting can be changed from 1°C to 0.5°C.
For details on the changing procedure, refer to information on page onward.)
6.2.3 Thermostat Control in Dry Operation
While in dry operation, the thermostat control is conducted according to a suction temperature
at the time of starting the dry operation.
Assuming that the suction air temperature at the time of starting the dry operation is Tro and the
suction air temperature in operation is Tr,
Furthermore, while in dry operation mode, fans operate at L flow rate, stops for a period of six
minutes while the thermostat is OFF, and then return to operation at L flow rate. (This control is
used to prevent a rise in indoor temperature while in thermostat OFF mode.)
Cooling operation:
Heating operation:
Normal
operation
Thermostat OFF
Tr < Set temperature -1 ºC
Normal
operation
Thermostat OFF
Tr > Set tempe1 º C
Tr: Temperature detected with the suction
air thermistor (R1T)
when Tro
≤
24.5 º C:
when Tro > 24.5 º C:
In dry operation
In dry operation
Tr < Tro - 1 º C
Tr < Tro - 1.5 º C
Thermostat OFF
Thermostat OFF
Tro: Suction air temperature at the
time of starting the dry operation
Tr: Temperature detected with the
suction air thermistor (R1T)