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Special Control
SiEN18-622
104
Function
3.3
Defrosting Operation
The defrost operation is performed to solve frost on the outdoor unit heat exchanger when
heating, and the heating capacity is recovered.
[Conditions to start]
The defrost operation is started referring following conditions.
Outdoor heat exchanger heat transfer co-efficiency
Temperature of heat-exchange (Tb)
Low pressure equivalent saturation temperature (Te)
Timer (2 hours at the minimum)
In addition, outdoor heat-exchange co-efficiency is derived from Tc, Te, and the compressor
load.
* From the preparing operation to the defrost operation, and from the defrost operation to the
operation after defrost, the compressor stops for 2 min. to reduce noise on changing of the four
way valve.
Outdoor unit actuator
Defrost preparation
operation
Defrost operation
Post Defrost operation
Compressor
Upper limit control
124 Hz Full load
2-step increase from
36 Hz Unload to
(Pc - Pe>0.4 MPa)
every 20 sec.
Outdoor unit fan
STEP8
OFF
STEP8
Four way valve
ON
OFF
ON
Main electronic expansion valve
(EV1)
SH control
480 pls
55 pls
Subcooling electronic expansion
valve (EV3)
0 pls
0 pls
0 pls
Hot gas bypass valve (SVP)
OFF
ON
ON
Ending conditions
2 min.
•
15 min.
•
Tb>11°C
•
Ts1 - Te<5°C
•
160 sec.
•
Pc - Pe>0.4MPa
or
&
{
or
Indoor actuator
During defrost
Indoor unit fan
Thermostat ON unit
OFF
Stopping unit
OFF
Thermostat OFF unit
OFF
BP unit electronic expansion
valve
Thermostat ON unit
SH control
Stopping unit
80 pls
Thermostat OFF unit
SH control
Summary of Contents for FTKS50BVMB
Page 1: ...SiEN18 622 E Series Service Manual Applied Models zSuper Multi Plus Cooling Only Heat Pump ...
Page 105: ...Refrigerant Flow for Each Operation Mode SiEN18 622 92 Refrigerant Circuit ...
Page 157: ...Indoor Unit SkyAir Models SiEN18 622 144 Function ...
Page 312: ...SiEN18 622 Ceiling Mounted Cassette Type System Configuration 300 ...
Page 424: ...Method of Replacing The Inverter s Power Transistors Modules SiEN18 622 412 Troubleshooting ...
Page 446: ...Wiring Diagrams SiEN18 622 434 Appendix ...
Page 452: ...SiEN18 622 vi Index ...