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3-2. EXPANSION VALVE CONTROL (LEV CONTROL)
Linear expansion valve (LEV) is controlled by “Thermostat ON” commands given from each unit.
Indoor unit status LEV opening
Stop of all indoor unit Opening before stop → 500 pulse in 15 minutes
When outdoor unit is operating,
some indoor units stop and some
operate.
COOL : 5 pulse (full closed)
HEAT :(MXZ-2A / 3A30NA) : 140 pulse (slightly opened)
:(MXZ-3A30NA-
1
/ 4A ) : 100 → 59 pulse
Thermostat OFF in COOL or DRY
mode
When the outdoor unit operates (When the other indoor unit operates) : 5 pulse.
When outdoor unit stops. (When the other indoor unit stops or thermo off) :
Maintain LEV opening before stop → 500 pulse in 15 minutes
Thermostat ON in COOL or DRY
mode
• LEV opening for each indoor unit is determined by adding adjustment in accordance
with the number of operating unit and the capacity class to standard opening, based
on the operation frequency:
Ex.) Opening 130 pulse in standard opening 1 → Minimum 80 pulse, Maximum 205
pulse. (Capacity code 4 at 1 unit operation) (Capacity code 1 at 3 units operation)
• After starting operation, adjustment in accordance with intake super heat, discharge
temperature is included in standard opening.
1
NOTE: LEV opening in each frequency at DRY operation and COOL operation is the
same. However, velocity and compressor operation frequency controls are differ-
ent. See 3-3. OPERATIONAL FREQUENCY RANGE
(As far as the indoor unit velocity control goes, refer to DRY operation in MICRO-
PROCESSOR CONTROL in indoor unit.)
Thermostat OFF in HEAT mode
• When the outdoor unit operates. (When the other indoor unit operates) : 140 pulse.
• When the outdoor unit stops. (When the other indoor unit stops or thermo off) : Main-
tain LEV opening before stop → 500 pulse in 15 minutes. “
Thermostat ON in HEAT mode
• LEV opening for each indoor unit is determined by adding adjustment in accordance
with the number of operating unit and the capacity class to standard opening, based
on the operation frequency:
Ex.) Opening 120 pulse in standard opening 1 → Minimum 70 pulse, Maximum 165
pulse. (Capacity code 4 at 1 unit operation) (Capacity code 1 at 3 units operation)
• After starting operation, opening becomes the one that adjustment in accordance with
discharge temperature was added to basic opening.
1 “
1 LEV opening when the outdoor unit is operating: Upper limit 500 pulse, Lower limit 53pulse (MXZ-2A / 3A30NA), 59 pulse
(MXZ-3A30NA-
1
/ 4A).