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Special Control
SiUS281811EA
114
Part 4 Functions and Control
3.3 Defrost
Control
Pc: High pressure sensor detection value
Pe: Low pressure sensor detection value
Tb: Heat exchanger deicer temperature
Tc: High pressure equivalent saturation temperature
Te: Low pressure equivalent saturation temperature
Ts1: Suction pipe temperature detected by thermistor R3T
Defrost control is performed to melt frost on the outdoor heat exchanger when heating, and thus
recover heating capacity.
Starting conditions
Defrost operation is not conducted before 40 minutes have elapsed from the start of heating
operation.
After 40 minutes have elapsed, defrost operation starts when the following items meet the
reference values.
Heat transfer coefficient of the outdoor heat exchanger (The heat transfer coefficient of the
outdoor heat exchanger is computed from Tc, Te, and compressor loads.)
Outdoor heat exchanger deicer temperature (Tb)
Defrost operation starts every 2 hours, even if the reference values are not met.
∗
Between (A) defrost preparation control and (B) defrost control, and between (B) defrost control
and (C) control after defrost, the compressor stops for 1 minute to reduce noise on changing of the
four way valve.
Outdoor unit
actuator
Electric Symbol
(A) Defrost preparation
control
(B) Defrost control
(C) Control after defrost
18/24
class
30/36/42/48
class
Compressor
M1C
M1C
Upper limit control
140 Hz Full load
Increases 2 steps every 20
seconds from minimum
frequency until Pc – Pe >
0.4 MPa (58 psi) is
achieved.
Outdoor fan
M1F
M1F
M2F
STEP 8
OFF
STEP 8
Main electronic
expansion valve
Y1E
Y1E
SH control
480 pulse (Fully open)
55 pulse
Subcooling
electronic
expansion valve
—
Y3E
0 pulse
0 pulse
0 pulse
Four way valve
Y1S
Y1S
ON
OFF
ON
Hot gas bypass
valve
Y2S
—
OFF
ON
ON
Ending conditions
2 minutes
x
12 minutes
x
Tb > 11°C (51.8°F)
x
Ts1 – Te < 5°C (9°F)
OR
&
x
160 seconds
x
Pc – Pe > 0.4 MPa
(58 psi)
OR
Indoor unit actuator
Defrost control
Fan
Thermostat ON unit
OFF
Non-operating unit
OFF
Thermostat OFF unit
OFF
Electronic expansion valve
Thermostat ON unit
416 pulse
Non-operating unit
256 pulse
Thermostat OFF unit
416 pulse
Содержание SkyAir RZR-TA Series
Страница 1: ...Service Manual Cooling Only 60 Hz Heat Pump 60 Hz RZR TA RZQ TA Series SiUS281811EA...
Страница 202: ...SiUS281811EA 196 Part 6 Service Diagnosis 5 15 Fan Motor Connector Check for FTQ TA 311...
Страница 321: ...SiUS281811EA 315 Part 7 Appendix 1 Wiring Diagrams 316 1 1 Outdoor Unit 316 1 2 Indoor Unit 320 Part 7 Appendix...
Страница 322: ...Wiring Diagrams SiUS281811EA 316 Part 7 Appendix 1 Wiring Diagrams 1 1 Outdoor Unit RZR18 24TAVJU RZQ18 24TAVJU 3D115455...
Страница 323: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 317 RZR18 24TAVJUA RZQ18 24TAVJUA 3D124495...
Страница 324: ...Wiring Diagrams SiUS281811EA 318 Part 7 Appendix RZR30 36 42 48TAVJU RZQ30 36 42 48TAVJU 3D115456...
Страница 325: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 319 RZR30 36 42 48TAVJUA RZQ30 36 42 48TAVJUA 3D124500...
Страница 326: ...Wiring Diagrams SiUS281811EA 320 Part 7 Appendix 1 2 Indoor Unit FCQ18 24 30 36 42 48TAVJU 3D115647A...
Страница 327: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 321 FHQ18 24 30PVJU FHQ36 42MVJU 3D048116C...
Страница 328: ...Wiring Diagrams SiUS281811EA 322 Part 7 Appendix FAQ18 24TAVJU 3D114844B...
Страница 329: ...SiUS281811EA Wiring Diagrams Part 7 Appendix 323 FBQ18 24 30 36 42 48PVJU 3D065984J...