Defrosting Operation - Daikin VRV II RXYQ5MY1B Service Manual

Special Control
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 discharging valve
(SVG)
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.
88
Defrost preparation
operation
Upper limit control
STEP8
or
STEP9
ON
SH control
0 pls
OFF
ON
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
1400 pls
0 pls
ON
ON
OFF
ON
• 12 min.
or
• Ts >11°C
During defrost
SiE39-404
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
ON
• 160 sec.
or
• Pc - Pe>0.4MPa
OFF
OFF
OFF
512 pls
512 pls
512 pls
Function