Defrosting Operation - Daikin R410As Service Manual

Si39-302
3.3

Defrosting Operation

Outdoor unit actuator
Compressor
Outdoor unit fan
Four way valve
Main motorized valve (EV1)
∗Value in ( ) are for RXYQ5M only.
Subcooling motorized valve (EV2)
Hot gas bypass valve (SVP)
Oil equalization valve (SVO)
Receiver gas charging valve (SVL)
Receiver gas discharging valve
(SVG)
Non-operating unit gas discharging
valve (SVSG)
Non-operating unit liquid pipe stop
valve (SVSL)
Ending conditions
* 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 Defrost operation.
(Non-operating unit stops during "Defrost preparation operation".)
* Actuators are based on RXYQ16M.
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
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 + ON
OFF
OFF
0 pls (1400pls)
0 pls
ON
ON
OFF
OFF
OFF
ON
• 12 min.
or
• Ts >11°C
During defrost
Special Control
Post Defrost operation
1-step increase from
(74 Hz + OFF + OFF) to
(Pc - Pe>0.4 MPa)
STEP9
ON
200 pls
0 pls
ON
ON
OFF
OFF
OFF
ON
• 160 sec.
or
• Pc - Pe>0.4MPa
OFF
OFF
OFF
512 pls
512 pls
512 pls
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