Mitsubishi Electronics MUZ-FDNA - U Manuel D’Utilisation

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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-

 / 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-

/ 4A).