SiBE37-701_B
Special Control
Function
126
3.4
Defrost Operation
[Start conditions]
Referring to the following conditions, start defrost operation.
• When there is a decrease in the coefficient of heat transfer of outdoor unit heat exchanger
• When there is a drop in the temperature of outdoor unit heat exchanger outlet (Tb)
• When the low pressure stays low for a certain amount of time (2 hours minimum)
Furthermore, the thermal continuity of outdoor unit heat exchanger is calculated by Tc, Te, and compressor loads.
Defrosting outdoor unit actuator
Symbol
Elect.
symbol
Defrost operation
Operation after defrost
REYQ
REMQ
Compressor 1
—
M1C M1C REYQ8•10•12P: 232Hz+ON
REYQ14•16P: 232Hz+232Hz
REMQ8P: 210Hz
REMQ10•12P: 210Hz+ON
REMQ14•16P: 202Hz+ON+ON
REYQ8•10•12P: upper limit
124Hz(STD Holds)
REYQ14•16P: 232Hz+232Hz
REMQ8P: 210Hz
REMQ10•12P: 210Hz+ON
REMQ14•16P: 210Hz+ON+ON
Compressor 2
M2C M2C
Compressor 3
—
M3C
Outdoor unit fan 1
—
M1F M1F
Outdoor unit fan 2
M2F M2F
Four way valve (Heat exchanger
switch)
20SA
Y2S
Y9S
Y3S OFF
OFF
Four way valve (Dual pressure gas
pipe switch)
20SB Y8S Y2S Holds
Holds
Electronic expansion valve (Main)
EVM
Y1E
Y3E
Y1E 1375pls
0pls
Electronic expansion valve
(Subcooling)
EVT
Y2E
Y5E
Y3E SH control
0pls
Electronic expansion valve
(Refrigerant charge)
EVJ
Y4E Y2E 80pls
80pls
Solenoid valve (Main bypass)
SVE
Y5S
Y10S
Y6S ON
OFF
Solenoid valve (Hot gas)
SVP
Y4S Y5S OFF
OFF
Solenoid valve (Refrigerant
regulator liquid pipe)
SVL
Y3S Y4S 0pls
0pls
Solenoid valve (Refrigerant
regulator gas vent pipe)
SVG
Y1S Y1S 0pls
0pls
Solenoid valve (Refrigerant
regulator discharge pipe)
SVO
Y7S Y7S 0pls
0pls
Solenoid valve (Refrigerant
regulator discharge pipe)
SVT
Y6S Y8S 0pls
0pls
End conditions
REYQ8 to 16P (by unit)
•
6 min. and 30 sec.
•
Tb > 11°C continues for a
period of 90 consecutive sec.
•
Pc_max > 3.04MPa
REMQ8 to 12P (by unit)
•
5 min. and 30 sec.
•
Tb > 11°C for a period of
10 consecutive sec.
•
Pc_max > 3.04MPa
REMQ14 and16P (by unit)
•
5 min. and 30 sec.
•
Tb > 11°C for a period of 30
consecutive sec.
•
Pc_max > 3.04MPa
•
30 sec.
•
Pc_max>3.04MPa
&
Pcmax>2.45MPa
Pcmax<2.36MPa
Pcmax>3.04MPa
Pcmax<2.95MPa
OFF
FAN STEP 4
FAN STEP 6
Pcmax>2.45MPa
Pcmax<2.36MPa
Pcmax>3.04MPa
Pcmax<2.95MPa
OFF
FAN STEP 4
FAN STEP 6
or
or
or
or
Summary of Contents for REYQ8-48PY1B
Page 1: ...Service Manual REYQ8 48PY1B R 410A Heat Recovery 50Hz SiBE37 701_B ...
Page 456: ...Piping Installation Point SiBE37 701_B 445 Appendix ...
Page 460: ...Example of connection SiBE37 701_B 449 Appendix ...
Page 476: ...Revision History Date News No Contents 2010 9 10 M 10011 Correction of service manual ...