10
NOTE
: Opening increases and decreases to be in the target discharge temperature during operation.
Opening
completely
Positioning
Power ON
Initial opening
Standard opening
Remote
controller
ON
Operation
Thermostat
OFF
Standard opening
Thermostat
ON
Opening in stop
Operation
Opening in stop
Remote
controller
OFF
Opening
completely
Remote
controller
ON
Positioning
Standard opening
Operation
Time
LEV opening
Initial opening
Initial opening
Open
Close
(2) LEV time chart
1-6. EXPANSION VALVE CONTROL (LEV CONTROL) (MU-GD80VB, MUH-GD80VB)
LEV (Expansion valve) is controlled by “Thermostat ON” commands given from the unit.
Standard
specification
Control range
Minimum: 54 pulse, Maximum: 500 pulse
Drive speed
30 ~ 90 pulse/second
Opening set
The setting is always in opening direction.
(To close LEV, it is closed to the pulse smaller than the one set finally.
Then LEV is opened to the final setting pulse.)
General operation
Stop of indoor unit
Opening in stop: 150 pulse
→
LEV opening is set to become 500 pulse after 3 min-
utes.
Remote controller ON
LEV positioning (LEV is closed completely at once)
Power ON (Breaker ON)
LEV is positioned. However, afterwards, LEV is not positioned when the remote
controller is turned ON for the first time after the power ON.
Approximately for 2 minutes after
compressor has started.
Opening is set by the initial opening.
(Initial opening is set according to each operation mode and outer temperature con-
ditions.)
Approximately 2 to 13 minutes (for
11 minutes) after compressor has
started.
Opening is set by standard opening.
(Standard opening is set according to each operation mode and outer temperature
conditions.)
13 minutes after compressor has
started.
LEV opening is corrected once every 2 minutes so that discharge temperature
becomes the target discharge temperature.
(When the discharge temperature is lower than the target temperature: LEV is cor-
rected in closed direction, when the discharge temperature is higher than the target
temperature: LEV is corrected in opening direction.)
Thermostat OFF
Opening in stop: 150 pulse
→
LEV is set to the initial opening after about 3 minutes.
Thermostat ON
Same as the starting of compressor operation
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.
Operation mode
Target discharge temperature (°C)
HEAT (
MUH-GD80VB
)
85
COOL (Normal)
80
COOL (
∆
RT is less than 2°C, or
∆
RT is 2°C or more and less than 3°C.)
70
COOL (
∆
RT is 3°C or more.)
65
NOTE:
When the discharge temperature is 50°C or less on the cool operation, or is 49°C or less on heat operation
(
MUH-GD80VB
), LEV opening is set in 54 pulse.
When this state continues for 20 minutes, the compressor is stopped and restarts in 3 minutes.
When the compressor is stopped, the indoor unit indicates the abnormality of refrigerant system and stops.
(OPERATION INDICATOR lamp is 10-time flashing ON and OFF.)
(1) Control data
Reference value of target discharge temperature
