Fujitsu AB* A12GATH, Service Manual

Page: 33 / 241

2-3-2 Compressor speed control
(1) Speed range and controlling
- On operation range: 20 - 115 rps*
- Changing interval: 60 sec.
- When the multi connection outdoor unit has the same type of compressor, all of compressors rotational speed are controlled
with the same speed at the normal operating condition.
- All of the outdoor unit compressors must start at the start-up process.
[rps]
[sec]
60
60
120
180
90
Hold 60 seconds
Normal control starts
- The lower limit speed at start-up changes depending on the outdoor temperature
[rps]
[ ]
- 10
24(20)
7 21
74(60)
37(30)
3.80MPa
Maximum speed: 80rps
Maximum speed: 90rps
Outdoor temperature
- Cold Start start process
Condition: Outdoor temperature below 21 and the system stopped for more than 1 hour]
[rps]
[sec]
1 min or Max.15 min.
70
Normal control starts
- The Normal start process (Except the condition of Cold start)
The first target speed is decided by indoor unit capacity demand.
The upper limit speed at starting is made 60 rps and is raised in 30 rps to 90 rps after 60 seconds.
(The upper speed limit depends on the operating high pressure value)
30 sec. 10 sec.
Hold Control HP*
Process 1
Process 2
Process 3
Control HP*: Change the rps so that high pressure does not reach to protection condition
65cc (79cc) type compressor
115
*The maximum speed: 115 rps
---> Cooling 100 rps
Heating 115 rps
3.25MPa
02-05