Specifications

SiBE341027 Detailed Control Functions
Function 59
2.6.2 Defrost Operation
To defrost the outdoor unit heat exchanger while in heating operation, the defrost operation is conducted to
recover the heating capacity.
[Start conditions]
Referring to the set conditions for the following items, start the defrosting operation.
• A lapse of every 1 hour during high-load operation
• A lapse of every 2 hours during low-load operation
* In the case of multi-outdoor-unit system,
Master unit: Performs the operations listed in the table above.
Slave units: Operating units perform the operations listed in the table above.
Non-operating units perform the operations listed in the table above from the oil return operation.
(Non-operating unit stops during “oil return preparation operation”.)
Part Name
Electric Symbol
Defrost operation
RQYQ8P PQYQ10·12P PQYQ14·16P
Compressor
M1C M1C M1C 143Hz
–M2CM2CON
––M3CON
Outdoor unit fan M1F M1F M1F, M2F OFF
Four way valve Y3S Y3S Y3S OFF
Electronic expansion valve (Main) Y1E Y1E Y1E 480 pls
Electronic expansion valve (Main 2) – – Y2E
Electronic expansion valve
(Subcooling)
Y2E Y2E Y3E 0 pls
Solenoid valve (Hot gas) Y1S Y1S Y1S ON
Solenoid valve (Receiver gas vent) Y8S Y8S Y8S ON
Solenoid valve (Circuit of oil return) Y5S Y5S Y5S OFF
Solenoid valve (Close liquid pipe for
stopped outdoor unit)
Y6S Y6S Y6S ON
Solenoid valve (Main electronic
expansion valve bypass)
Y10S Y10S – ON
Solenoid valve (Refrigerant
regulator gas vent pipe)
Y11S Y11S Y10S OFF
Solenoid valve (Refrigerant
regulator liquid pipe)
Y12S Y12S Y11S OFF
Solenoid valve (Refrigerant
regulator gas pipe)
Y13S Y13S Y12S OFF
Solenoid valve (Refrigerant
regulator liquid outlet)
Y14S Y14S Y13S OFF
Solenoid valve (Receiver liquid level) Y7S Y7S Y7S OFF
Solenoid valve (Mixing unit inlet) Y4S Y4S Y4S OFF
Solenoid valve (Bypass) Y2S Y2S Y2S OFF
Solenoid valve (Oil regulator outlet) Y9S Y9S Y9S ON
Indoor unit actuator During defrost
Fan
Thermostat ON unit OFF
Stopping unit OFF
Thermostat OFF unit OFF
Electronic expansion valve
Thermostat ON unit 512 pls
Stopping unit 512 pls
Thermostat OFF unit 512 pls