Control Specification
SiUS12-928_A
45
Function and Control
3.2
Frequency Control
Outline
Frequency that corresponds to each room’s capacity is determined according to the difference
between the target temperature and the thermistor temperature of each room.
The function is explained as follows.
1. How to determine frequency
2. Frequency command from an indoor unit (Difference between a room thermistor temperature
and the target temperature)
3. Frequency command from an indoor unit (The ranked capacity of the operating room)
4. Frequency initial setting
5. PI control
Details
How to Determine Frequency
The compressor’s frequency is determined by taking the following steps.
1. Determine command frequency
Command frequency is determined in the following order of priority.
1. Limiting defrost control time
2. Forced cooling / heating
3. Indoor frequency command
2. Determine upper limit frequency
The minimum value is set as the upper limit frequency among the frequency upper limits of the
following functions:
Compressor protection, input current, discharge pipe temperature, low Hz high pressure limit,
heating peak-cut, freeze-up protection, defrost.
3. Determine lower limit frequency
The maximum value is set as the lower limit frequency among the frequency lower limits of the
following functions:
Four-way valve operation compensation, draft prevention, pressure difference upkeep.
4. Determine prohibited frequency
There is a certain prohibited frequency such as a power supply frequency.
Command fre
qu
ency
Limit fre
q
uency
Skip control
Upper limit f
u
nction
Compressor protection f
u
nction
Lo
w
er limit f
u
nction
Fo
u
r
w
ay
v
al
v
e operating compensation, etc.
Initial fre
qu
ency
PI control
Defrost control
Dropping f
u
nction
Inp
u
t c
u
rrent control, etc.
Upper limit fre
q
uency
FMAX
Lower limit fre
q
uency
FMIN
Tar
g
et fre
q
uency
(R2
8
31)
W
hen the shift of the fre
qu
ency is less than zero (
D
F<0)
b
y PI control,
the target fre
qu
ency is
u
sed as the command fre
qu
ency.
Summary of Contents for SUPER MULTI NX G Series
Page 1: ...SiUS12 928_A Applied Models Inverter Multi Heat Pump G Series J Series...
Page 7: ...SiUS12 928_A Table of Contents vi...
Page 10: ...SiUS12 928_A 1 List of Functions Part 1 List of Functions 1 Functions 3...
Page 11: ...SiUS12 928_A List of Functions 2...
Page 17: ...SiUS12 928_A Specifications 8...
Page 23: ...SiUS12 928_A Specifications Specifications 14...
Page 25: ...SiUS12 928_A Printed Circuit Board Connector Wiring Diagram 16...
Page 37: ...SiUS12 928_A Function and Control 28...
Page 69: ...SiUS12 928_A Control Specification Function and Control 60...
Page 71: ...SiUS12 928_A Operation Manual 62...
Page 73: ...SiUS12 928_A Duct Free System Operation Manual 64 2 Duct Free System 2 1 Remote Controller...
Page 84: ...Duct Free System SiUS12 928_A 75 Operation Manual...
Page 85: ...SiUS12 928_A Duct Free System Operation Manual 76 2 8 TIMER Operation...
Page 86: ...Duct Free System SiUS12 928_A 77 Operation Manual...
Page 87: ...SiUS12 928_A Duct Free System Operation Manual 78 2 9 Note for Multi System...
Page 88: ...Duct Free System SiUS12 928_A 79 Operation Manual...
Page 97: ...SiUS12 928_A Slim Duct Built In System Operation Manual 88...
Page 99: ...SiUS12 928_A Service Diagnosis 90...
Page 169: ...SiUS12 928_A Removal Procedure 160...
Page 225: ...SiUS12 928_A Trial Operation and Field Settings 216...
Page 235: ...SiUS12 928_A Appendix 226...