Capacity Control; Capacity Of Compressor Operation; Target Low-Pressure And High-Pressure Control; 2 Outdoor Units - Fujitsu Airstage VR-II Series Service Manual

2-4-3 Capacity Control

(1) Capacity of compressor operation

The inverter compressor is able to control the amount of required refrigerant circulation in details.
[rps]
0.1 rps
on controlling steps1
115
20
By combining the operation of inverter compressors, the amount of required refrigerant circulation acceding to cooling and heating
load can be supplied from compressor efficiently.
Ex) Combnation of 65cc compressor / Heating (Heating main)
[rps]
Total capacity
115
20
INV
Stand-alone

(2) Target low-pressure and high-pressure control

<Cooling>
In order to make the evaporation pressure of the indoor unit at the proper pressure on a variety of operations,
capacity of the compressor will be controlled by low-pressure sensor.
<Heating>
In order to make the condensation pressure of the indoor unit at the proper pressure on a variety of operations,
capacity of the compressor will be controlled by high-pressure sensor.
<Cooling main / Heating main>
In order to keep evaporation pressure / condensation pressure of the indoor unit at the proper pressure on a
variety of operations, capacity of the compressor and the capacity Heat exchange(incl. fan controll) will be
controlled by both of pressure sensor at the sametime
Target low-pressure and high pressure temperature depends on system capacity, capacity of compressor operation,
pipe length, and capacity shift switch settings.
Operating Range
(20 to 115 rps*)
[rps]
2 times 115
48
20
[BTU]

2 Outdoor units

On operating range: 20 to 115 rps*
Capacity
3 times 115
Total capacity
INV
INV
[BTU]
02-05
*The maximum speed: 115 rps
Cooling (Cooling main) 100rps
Heating (Heating main) 115rps
[rps]
INV
68
INV
48
20
INV
3 Outdoor units
Total capacity
[BTU]