8-9. LEV control
LEV (Expansion valve) is controlled by “Thermostat ON” commands given from the unit.
Controlled range
Basic specification
Minimum : 54 pulse, Maximum : 500 pulse
Drive speed
30 ~ 90 pulse / second
Opening set
Stop of indoor unit
Opening in stop : 150 pulse
➔
LEV opening is set to becomes 500 pulse
after 3 minutes passed.
Remote controller ON
LEV positioning (LEV is closed completely at once)
Power ON (Breaker ON)
LEV is positioned. However, afterwards, LEV is not positioned at the first
remote controller ON.
Approximate for 2 minutes since
compressor has started.
Opening is set by the initial opening.
(Initial opening is set according to each operation modes and
outer temperature conditions.)
From approximate 2 minutes to
approximate 13 minutes
(for 11 minutes) since compressor
has started.
Opening is set by standard opening.
(Standard opening is set according to each operation modes and
outer temperature conditions.)
After 13 minutes passed since
compressor has started.
LEV opening is corrected to be once every 2 minutes so that discharge
temperature becomes the target discharge temperature.
(When the discharge temperature is lower than target one : LEV is corrected in
closed direction, when the discharge temperature is higher than target one :
LEV is corrected in opening direction.)
At thermostat OFF
Opening in stop : 150 pulse
➔
LEV is set to the initial opening after about
3 minutes passed.
At thermostat ON
Same as the starting of compressor operation
At remote controller OFF
Opening in stop : 150 pulse
➔
LEV is set so that the opening is opened
completely at the speed of 4 pulse every 5 seconds in opening after about
3 minutes passed.
General operation
The setting is always in opening direction.
(To close the LEV, it is closed to the pulse smaller than the one which is
set finally. Then the LEV is opened to the final setting pulse.)
(1) LEV opening correction by discharge temperature
The LEV opening is corrected according to the temperature difference between target discharge temperature (Tb) and
actual discharge temperature (Ta).
1
The LEV correction is used properly for two kinds according to the LEV opening status at operation off.
Rank
Ta (F
-
)
more than Tb+18
Tb+9 to Tb+18
Tb+4 to Tb+9
Tb-4 to Tb+4
Tb-9 to Tb-4
Tb-18 to Tb-9
less than Tb-18
100 pulse or less
(Pulse)
Cooling
5
2
1
0
-1
-2
-5
NOTE : Discharge temperature : Ta, Target discharge temperature : Tb
100 pulse or more
(Pulse)
Cooling
20
10
2
0
-2
-5
-10
Opening immediately before having stopped last time
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