Thermostat Control While In Normal Operation; Thermostat Control In Dry Operation - Daikin RXYQ96PYDN Service Manual

SiUS34-801A_b
4.1

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 -1.8°F from the set temperature while in cooling
operation or of +1.8°F from that while in heating operation.
Cooling operation:
Heating operation:
While in a single remote controller group control, the return air sensor is only used from this
control. While in heating operation, cassette-mounted indoor units conduct the thermostat control
by a value compensated by -3.6°F for the value detected with the body thermostat. Through field
settings, the thermostat differential setting can be changed from 1.8°F to 0.9°F.
4.2

Thermostat Control in Dry Operation

While in dry operation, the thermostat control is conducted according to a return air temperature at
the time of starting the dry operation.
Assuming that the return air temperature at the time of starting the dry operation is Tro and the
return air temperature in operation is Tr:
when Tro ≤ 76.1ºF:
when Tro > 76.1ºF:
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.
Indoor Unit
Tr < Set temperature -1.8ºF
Normal
Thermostat OFF
operation
Tr > Set temperature +1.8ºF
Normal
Thermostat OFF
operation
In dry operation
In dry operation
Thermostat Sensor in Remote Controller
Tr: Temperature detected with the suction
air thermistor (R1T)
Tr < Tro -1.8ºF
Thermostat OFF
Tr < Tro -2.7ºF
Thermostat OFF
Tro: Suction air temperature at the
time of starting the dry operation
Tr: Temperature detected with the
suction air thermistor (R1T)
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