Control Specification
SiUS071735EA
31
Functions and Control
Initial Frequency
When starting the compressor, the frequency is initialized according to the
∆
D value of the indoor
unit.
∆
D signal: Indoor frequency command
The difference between the room thermistor temperature and the target temperature is taken as the
∆
D value and is used for
∆
D signal of frequency command.
∆
D signal for cooling
∗
OFF = Thermostat OFF
∆
D signal for heating
∗
OFF = Thermostat OFF
PI Control
1. P control
The
∆
D value is calculated in each sampling time (20 seconds), and the frequency is adjusted
according to its difference from the frequency previously calculated.
2. I control
If the operating frequency does not change for more than a certain fixed time, the frequency is
adjusted according to the
∆
D value.
When
∆
D value is low, the frequency is lowered.
When
∆
D value is high, the frequency is increased.
3. Frequency control when other controls are functioning
When frequency is dropping:
Frequency control is carried out only when the frequency drops.
For limiting lower limit:
Frequency control is carried out only when the frequency rises.
4. Upper and lower limit of frequency by PI control
The frequency upper and lower limits are set according to the command of the indoor unit.
When the indoor or outdoor unit quiet operation command comes from the indoor unit, the upper
limit frequency is lower than the usual setting.
Temperature
difference
∆
D
signal
Temperature
difference
∆
D
signal
Temperature
difference
∆
D
signal
Temperature
difference
∆
D
signal
–2.0°C (–3.6°F)
∗
OFF
0°C (0°F)
4
2.0°C (3.6°F)
8
4.0°C (7.2°F)
12
–1.5°C (–2.7°F)
1
0.5°C (0.9°F)
5
2.5°C (4.5°F)
9
4.5°C (8.1°F)
13
–1.0°C (–1.8°F)
2
1.0°C (1.8°F)
6
3.0°C (5.4°F)
10
5.0°C (9.0°F)
14
–0.5°C (–0.9°F)
3
1.5°C (2.7°F)
7
3.5°C (6.3°F)
11
5.5°C (9.9°F)
15
Temperature
difference
∆
D
signal
Temperature
difference
∆
D
signal
Temperature
difference
∆
D
signal
Temperature
difference
∆
D
signal
–1.5°C (–2.7°F)
∗
OFF
0.5°C (0.9°F)
4
2.5°C (4.5°F)
8
4.5°C (8.1°F)
12
–1.0°C (–1.8°F)
1
1.0°C (1.8°F)
5
3.0°C (5.4°F)
9
5.0°C (9.0°F)
13
–0.5°C (–0.9°F)
2
1.5°C (2.7°F)
6
3.5°C (6.3°F)
10
5.5°C (9.9°F)
14
0°C (0°F)
3
2.0°C (3.6°F)
7
4.0°C (7.2°F)
11
6.0°C (10.8°F)
15
Summary of Contents for FDMQ-R Series
Page 12: ...SiUS071735EA 1 List of Functions Part 1 List of Functions 1 Functions 2...
Page 14: ...SiUS071735EA 3 Specifications Part 2 Specifications 1 Specifications 4...
Page 120: ...Check SiUS071735EA 109 Service Diagnosis 15 18 24 class R25105 1 2 3 4 Multimeter...
Page 122: ...Check SiUS071735EA 111 Service Diagnosis 15 18 24 class R20704 W V U DC_P1 DC_N1...
Page 140: ...Piping Diagrams SiUS071735EA 129 Appendix RX24RMVJU A 3D092249A...
