Fujitsu Airstage UTP-RU01AH, Service Manual

Page: 42 / 246

02 - 07
Under The heat exchanger capacity is controlled using the 4WV, fan, and EEV according to the target high and low pressures.
The method for changing the capacity of the heat exchanger differs depending on the operation mode.
2-5-1 Operation mode selection and controlling
2-5 HEAT EXCHANGER CAPACITY CONTROL
System demand Heat-Ex conditions Controling device Control target
Cooling Condensor Fan Motor + 4WV (ON/OFF) +EEV Target High pressure
Heating Evaporator Fan Motor (Max rpm) + 4WV (ON) +EEV Maximum control
Cooling main Condensor Fan Motor + 4WV (ON/OFF) + EEV Target High / Low pressure
Heating main Evaporator Fan Motor + 4WV (ON) + EEV Target High / Low pressure
(1) Cooling (In case of 3 outdoor units connection)
Heat Exchanger condition: Condensor
- 4WV ON / OFF (Dpending on HEX capacity shift)
Fan speed Controlling range
- 0 to 500 rpm Only one HEX in use
- 300 to 500 rpm During HEX capacity shift
- Over 500 rpm Full of Heat-Ex capacity
Heat Exchanger capacity shift controlling
- Increas: Upper HEX has a priority in usage condition.
(No available Upper HEX, Lower HEX use)
- Decrease: Lower HEX has a priority in stop condition.
880
500
300
0
Number of Condensor
1 2 3 4 5 6
Fan Speed
(rpm)
Target High pressure > Operating High Pressure
Target High pressure < Operating High Pressure
(2) Heating
Heat Exchanger condition: Evaporator
- 4WV ON state
Fan speed Controlling range
- Maximum speed
Heat Exchanger capacity shift controlling
- Use all of available HEXs (Maximum capacity)
880 (920)
0
Number of Evaporator
Maximum number of HEX available in use
Fan Speed
(rpm)
2-5-2 Capacity control
(3) Cooling Main / Heating Main (In case of 3 outdoor units connection)
Heat Exchanger condition: Depending on the difference between operating pressure and the Target High pressure and the Target Low pressure.
Fan speed controlling: Depending on the condition of HEX (Condensor / Evaporator)
Heat Exchanger capacity shift controlling:
- Increas: Upper HEX has a priority in usage condition.
(No available Upper HEX, Lower HEX use)
- Decrease: Lower HEX has a priority in stop condition.
880
500
300
0
Number of Evaporator
6 5 4 3 2 1 1 2 3 4 5 6
Fan Speed
(rpm)
Number of Condensor
Master r
HEX1
HEX2
Slave1 r Slave2 r
The heat exchanger is operated at maximum efficiency by using each outdoor unit. (Max. 6 Heat exchanger can be used)
HEX1
HEX2
HEX1
HEX2
Heating Main
Cooling Main
(920)
(500)
(300)
(920)
(500)
(300)
( ) :L-Chassis
( ) :L-Chassis
( ) :L-Chassis