(6) Electronic expansion valve (LEV)
1) Initial processing after power turned on
After the power is turned on, full close processing is performed as initial drive processing.
a) A 2200 pulses down is output from power on.
b) At the end of 2200 pulse down output, 60 pulses up is output.
c) Sixty pulses up output ends initial processing. At this point, the valves are fully closed.
2) Control contents
3) Normal LEV control
a) The operation frequency when the compressor is started (including after defrosting reset) determines the stan-
dard opening angle.
b) After a) above, sub cool (SC) shown below controls the LEV opening angle.
<Definition of SC>
Cooling: SC = TH3 (outdoor-side refrigerant circuit)-TH1 (outdoor-side refrigerant circuit)
Heating: SC = TH5 (indoor-side refrigerant circuit)-TH2 (indoor-side refrigerant circuit)
<LEV control>
LEV is controlled so that SC is equal to SCm.
SC < SCm:
LEV opening angle is made smaller
SC > SCm:
LEV opening angle is made larger
SC = SCm:
LEV opening angle remains unchanged
SCm = 5~15 (SCm is different with Indoor-side.)
4) Transient LEV control
a) When the outlet temperature (outdoor-side TH2) rises
When the outlet temperature (outdoor-side TH2) exceeds 115
°
C, the LEV opening angle is made larger.
(7) Service functions
1) Abnormality history clear
a) When DIP SW1-2 is turned ON while the compressor is operating or stopped, the abnormality history is cleared.
(5) Bypass solenoid valve control (SV1)
1) Control at cooling
a) While the compressor is stopped, the solenoid valve is OFF.
b) When the power is turned on, or when the compressor is restarted after it has been stopped for 30 minutes or
longer, if the liquid temperature (TH1) is 25˚C or higher then the solenoid valve turns ON for 2 minutes.
c) When the power is turned on, or when the compressor restarted after it has been stopped for 30 minutes or
longer, the solenoid valve turns ON for 5 minutes if the liquid temperature (TH1) is staying below 25˚C.
d) The item b) or c) is applied to the mode change from heating to cooling.
e) When the previous operation mode is cooling and the compressor restarted within 30 minutes after it’s stopping
by
the tripping of 63H2, the solenoid valve turns ON for 2 minutes.
2) Control at heating
a) While the compressor is stopped, the solenoid valve is OFF.
b) When the power is turned on, or when the compressor restarted after it has been stopped for 30 minutes or
longer, the solenoid valve turns ON for 2 minutes if the liquid temperature (TH1) is staying above 8˚C.
c) When the power is turned on, or when the compressor restarted after it has been stopped for 30 minutes or
longer, the solenoid valve turns ON for 5 minutes if the liquid temperature (TH1) is staying below 8˚C.
d) The item b) or c) is applied to the mode change from cooling to heating.
e) When the control pressure switch (63H2) trips, the solenoid valve turns ON.
f) If 63H2 resets 15 minutes after tripping, the solenoid valve turns OFF.
g) During defrosting, the solenoid valve turns ON.
h) When the previous operation mode is heating and the compressor restarted within 30 minutes after it’s stopping
by the tripping of
63H2, the solenoid valve turns ON for 2 minutes.
i) When the previous operation mode is heating, and the compressor restarted within 30 minutes after the tripping
of 63L, the solenoid valve turns ON for 2 minutes.
At compressor starting
At compressor stopping
At defrosting
Normal
LEV output opening angle
Initial opening angle
1000 pulses
2000 pulses (full close)
See next item
Opening angle control range
Approx. 1000 to 2000 pulses
–
–
1000 to 1500 pulses
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