Service manual

SiUS28-902_a Basic Control
Function 18
2.2 Compressor PI Control
Compressor PI Control
Carries out the compressor capacity PI control to maintain Te at constant during cooling
operation and Tc at constant during heating operation to ensure stable unit performance.
[Cooling operation]
[Heating operation]
RZQ18 · 24 · 30P
∗ Compressors may operate in a pattern other than those listed
in above tables subject to the operating conditions.
Controls compressor capacity to adjust Te to
achieve target value (TeS).
Te : Low pressure equivalent saturation temperature
(°F)
Te setting (Set in Set-up mode 2) TeS : Target Te value
(Varies depending on Te setting, operating
frequency, etc.)
LM (Normal)
(factory
setting)
H
37.5 43 48
Controls compressor capacity to adjust Tc to
achieve target value (TcS).
Tc : High pressure equivalent saturation temperature
(°F)
Tc setting TcS : Target Tc value
(Varies depending on Tc setting, operating
frequency, etc.)
LM (Normal)
(factory
setting)
H
109.5 115 120
STEP INV.
1 52Hz
2 57Hz
3 62Hz
4 68Hz
5 74Hz
6 81Hz
7 88Hz
8 96Hz
9 104Hz
10 110Hz
11 116Hz
12 124Hz
13 133Hz
14 143Hz
15 158Hz
16 165Hz
17 177Hz