Capacity Control Of Outdoor Fan And Heat Exchanger - Mitsubishi Electric PURY-P72 Service Handbook
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- Service handbook (403 pages) ,
- Service handbook (404 pages) ,
- Service handbook (387 pages)
Table of Contents
[ VII Control ]
-9- Capacity Control of Outdoor Fan and Heat Exchanger
(1) Control method
Depending on the capacity required, the rotation speed of the outdoor unit fan is controlled by the inverter to keep a constant
condensing temperature of (outside temperature +10°C [50°F]) during cooling operation and a constant evaporation temper-
ature of (0°C [32°F] =0.71
The OS in the multiple-outdoor-unit system operates at the actual outdoor unit fan control value that is calculated by the OS
based on the preliminary outdoor unit fan control value that the OC determines.
(2) Control
Outdoor unit fan stops while the compressor is stopped (except in the presence of input from snow sensor).
The fan operates at full speed for 5 seconds after start-up.(Only when TH7<0°C [32°F])
The outdoor unit fan stops during defrost operation.
On the P120 and P144 models of outdoor units, before the second fan goes into operation, the capacity of the first fan is
reduced to 50%.
(3) Outdoor unit heat exchanger capacity control patterns
Model
P72 model
P96 model
P120, P144 models
SV4c turns on when energized on the P96 model, and it turns on when de-energized on the P120 and P144 models.
(All other valves turn on when energized.)
HWE09130
Operation
Operation mode
patterns
Cooling-only
1
Cooling-main
2
3
4
5
Heating-only
1
Heating-main
1
2
Defrost
1
Cooling-only
1
Cooling-main
2
3
4
5
Heating-only
1
Heating-main
1
2
Defrost
1
Cooling-only
1
Cooling-main
2
3
4
5
Heating-only
1
Heating-main
1
2
Defrost
1
- 150 -
Solenoid valve
SV4a
SV4b
SV4c
OFF
OFF
-
OFF
OFF
-
OFF
ON
-
ON
OFF
-
ON
ON
-
ON
ON
-
ON
ON
-
ON
ON
-
ON
ON
-
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
OFF
ON
ON
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
SV4d
SV5c
ON
ON
OFF
ON
OFF
ON
OFF
ON
OFF
OFF
OFF
OFF
ON
OFF
OFF
OFF
OFF
OFF
ON
ON
OFF
ON
OFF
ON
OFF
ON
OFF
OFF
OFF
OFF
ON
OFF
OFF
OFF
OFF
OFF
ON
ON
OFF
ON
OFF
ON
OFF
ON
OFF
OFF
OFF
OFF
ON
OFF
OFF
OFF
OFF
ON
GB
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