Defrosting Operation - Daikin RXYQ72 Serivce Manual

SiUS39-601
3.3

Defrosting Operation

Outdoor unit actuator
Compressor
Outdoor unit fan
Four way valve
Main motorized valve (EV1)
Subcooling motorized valve (EV2)
Hot gas bypass valve (SVP)
Oil equalization valve (SVO)
Receiver gas charging valve (SVL)
Receiver gas discharging valve (SVG) OFF
Non-operating unit gas discharging
valve (SVSG)
Non-operating unit liquid pipe stop
valve (SVSL)
Ending conditions
Fan
Electronic expansion valve
<Defrost starting condition>
Defrost operation is started when the outdoor heat exchanger temperature becomes lower than deicer temperature.
Defrost operation is conducted once in max. 2 hours.
Function
Defrost preparation
operation
Upper limit control
STEP8
or
STEP9
ON
SH control
0 pls
OFF
ON
OFF
OFF
ON
2 min.
Indoor unit actuator
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Defrost operation
143 Hz + ON
OFF
OFF
0 pls
0 pls
ON
ON
OFF
OFF
OFF
ON
• 12 min.
or
• Ts >52°F
Special Control
Post Defrost operation
1-step increase from
(74 Hz + OFF) to
(Pc - Pe>58 psi)
STEP9
ON
200 pls
0 pls
ON
ON
OFF
OFF
OFF
ON
• 160 sec.
or
• Pc - Pe>58 psi
During defrost
OFF
OFF
OFF
512 pls
512 pls
512 pls
43