Daikin RZQ Series FCQ20EVA Service Manual page 31

SiME281501E
Outdoor Unit
(A) Compressor
Inverter drive unit varies compressor operating frequency to control capacity and other factors.
(B) Electronic Expansion Valve
Provides control to maintain optimum operating condition for high efficiency.
(C) Four Way Valve (Y1S)
Changes operation of cooling / heating.
Outdoor Air Thermistor (R1T)
Used for startup condition control and defrost control.
Discharge Pipe Thermistor (R2T)
Used for discharge pipe temperature protection during compression operation.
Suction Pipe Thermistor (R3T)
Used for suction super heat control by electronic expansion valve.
Heat Exchanger Distributor Pipe Thermistor (R4T)
•
•
Intermediate Heat Exchanger Thermistor (R5T)
Used for calculation of high pressure during cooling operation, and low pressure during heating
operation.
Liquid Pipe Thermistor (R6T)
Used for calculation of indoor unit heat exchanger subcooling during heating operation.
Radiation Fin Thermistor (R10T)
•
•
•
Indoor Unit
Indoor Suction Air Thermistor
Cooling:
Heating:
Indoor Heat Exchanger Thermistor
Cooling:
Heating:
Discharge Air Thermistor
Used for discharge air control.
NTC Thermistor
Used for current limiting.
Function and Control
Coil energized: heating
Coil not energized: cooling
Used for calculation of outdoor unit heat exchanger subcooling during cooling operation.
Used for judgement of the defrost IN and OUT condition.
Used for outdoor unit fan speed control.
Used for inverter radiation fin temperature control.
Used for pressure difference control.
FCQ FBQ
R1T R1T
R2T R2T
— R3T
— R5T
Thermostat control
•
PMV control
•
General frequency control
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Thermostat control
•
PMV control
•
General frequency control
•
Compressor frequency control (target Te)
•
Inverter current protection control
•
Freeze-up control
•
Compressor frequency control (target Tc)
•
Inverter current protection control
•
Hot start control
•
Peak cut-off
•
Functions of Main Components and Thermistors
Suction air thermistor
Heat exchanger thermistor
Discharge air thermistor
NTC thermistor
Thermistor
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