Processes and Functions
6
TD831077
VI - 6
5. Solenoid Valve Control
¶
In solenoid valve control, in addition to the conditions shown below, multiple valves may be controlled at the
same time. This is performed according to the respective control items.
(1) Liquid valve control (LIVP, LIVA, LIVS)
To properly control the discharge temperature, control is performed on a small amount of liquid refrigerant bypass-
ing to the suction pipe.
1
High discharge temperature
(2) Save valve control (PC unit only) (SAVE)
1
Save valve control is turned on according to the compressor control items.
2
Save valve control is turned on for five minutes after stopping the outdoor unit.
3
Save valve control may be turned on due to other control mechanisms (4-way valve adjustment control, hot
gas defrosting control).
(3) Hot gas valve (DEF)
1
Hot gas valve control is on during hot gas defrosting control. Also, hot gas valve control remains on for 10
seconds after hot gas defrosting control is finished.
2
Hot gas valve control remains off in situations besides (1) above.
Hot gas defrosting is performed simultaneously with hot gas valve control, but they end separately.
(4) Refrigerant adjustment valve control (REV)
1
Valve control is off when operation is stopped.
2
Valve control is turned on or off according to whether a shortage of refrigerant or overcharge is detected.
(5) Oil recovery valve control (ORVR)
1
See the oil recovery control and refrigerant movement control items.
2
Valve control of PC unit may be turned on when the compressor is operating during heating. This helps to
even out any low pressure in the operating units by passing through the balance pipes. (The balance pipes are
low pressure.) Priority is given to oil control.
(6) Bypass valve control (BPV)
1
See the oil recovery control and refrigerant movement control items.
2
The AD unit may be turned on when the compressor is operating during cooling. Some of the refrigerant
passes through the balance pipe and bypasses to the PC unit. (The balance pipe is high pressure.) Priority is
given to oil control.
(7) Balance valve control (BRV)
1
See the oil recovery control and refrigerant movement control items.
PC unit (PC compressor, AC compressor)
PC unit (SC compressor), AD unit
Rotary compressor
Scroll compressor
90
Discharge temperature
°
C
ON
70
OFF
1815_M_I
* The discharge temperature of the scroll compressor changes the line diagram for after
five minutes and less than five minutes after compressor startup.
1816_M_I
100
118
Discharge temperature
°
C
ON
ON
80
95
OFF
OFF
Less than five minutes
After five
minutes
Table 13
NOTE