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SiEN18-622
BP Unit Control
Function
117
6.3
SH Control in Cooling Operation
Purpose of the
Function
This function ensures appropriate refrigerant distribution when many room units are operating in
the cooling mode.
Outline
The heat exchanger temperatures and gas pipe temperatures of operating room units are
detected by the gas pipe thermistors, and the electronic expansion valves' flow rates are
corrected so as to adjust the difference between heat exchanger temperature and gas pipe
temperature of each room unit (hereafter referred to as SH) close to the target values.
When SH is higher than target value
→
Opens the valve of that room unit
When SH is lower than target value
→
Closes the valve of that room unit
When the liquid pipe temperature is lower than the heat exchanger temperature, the electronic
expansion valve is opened more than normal opening.
(Protection function to prevent rotor dew condensation)
The gas pipe temperature and indoor heat exchanger temperature are detected at the time of
every sampling time of 40 sec for the cooling SH control.
In order to prevent dew condensation in connection pipe, gas pipe lower-limit temperature is set
as follows.
Outdoor Temperature Gas Pipe Lower-Limit Temperature
-5
-22
0
-17
5
-12
10
-6
15
-1
20
4
25
8
30
8
35
8
40
8
45
8
0
2
4
6
8
10
12
-20
0
20
40
60
O
u
tdoor
a
ir temper
a
t
u
re
G
as
pipe lo
w
er-limit temper
a
t
u
re
(Q0
3
7
8
)
G
as
pipe lower-limit temper
a
t
u
re = × DOA - 17 (however
8
ºC or lower)
DOA:O
u
tdoor
a
ir temper
a
t
u
re
240
256
Summary of Contents for FTKS50BVMB
Page 1: ...SiEN18 622 E Series Service Manual Applied Models zSuper Multi Plus Cooling Only Heat Pump ...
Page 105: ...Refrigerant Flow for Each Operation Mode SiEN18 622 92 Refrigerant Circuit ...
Page 157: ...Indoor Unit SkyAir Models SiEN18 622 144 Function ...
Page 312: ...SiEN18 622 Ceiling Mounted Cassette Type System Configuration 300 ...
Page 424: ...Method of Replacing The Inverter s Power Transistors Modules SiEN18 622 412 Troubleshooting ...
Page 446: ...Wiring Diagrams SiEN18 622 434 Appendix ...
Page 452: ...SiEN18 622 vi Index ...