-57-
Item
At compressor is started
Compressor stopped during cool-
ing or heating mode
After operation has been stopped
During defrosting ((
❇
1) in Fig below)
During oil recovery operation
When low pressure (Ps) has
dropped during lower limit fre-
quency operation(15 minutes af-
ter start)
When the high pressure (Pd) is
risen up during lower limit fre-
quency operation (3 minutes after
starting)
When the discharge temperature
(Td) is risen up
Ps
Pd
after 30 seconds
Pd
❇
Example of operation of SV1
Compressor
Bypass
solenoid
valve (SV1)
(4-minute)
(2-minute)
(4-minute)
(3-minute)
Start
Thermo.
OFF
Thermo.
ON
Defrost
Stop
2) Bypass solenoid valves (SV1, SV4) [Both SV1 and SV4 are on (open)]
ON
OFF
SV1
ON for 4 minutes
ON
ON for 3 minutes
ON
ON during oil recovery operation af-
ter continuous low-frequency com-
pressor operation.
—
—
—
ON
Ps
Pd
ON when the high pres-
sure (Pd) exceeds the
control pressure limit.
OFF
SV4
—
—
—
Normally ON
—
3) Capacity control solenoid valve (SV22, SV32). (Model 500 only)
• Operation of solenoid valve
• SV22 and SV32 stand for SV2 and SV3 of the No. 2
compressor.
Solenoid valve
SV22
SV32
COMP
SV22
SV32
Coil
Valve
Coil
Valve
OFF
Open
OFF Closed
ON
Closed
ON
Open
Status
Full-load
(Operating at 100 %
capacity)
Un-load
(Capacity control
operation)
Pd
Pd
130˚C
(No. 1 compressor)
115˚C
(No. 2 compressor)
2 compressor)
• Td
and
• Pd
or
Ps
115˚C
(No. 1 compressor)
100˚C
(No.
Td
0.196 MPa
0.098 MPa
2.65 MPa
2.35 MPa and
2.70 MPa
2.35 MPa
and after 30
seconds.
1.96 MPa
1.96 MPa
0.34 MPa
