Mitsubishi Electric PURY-M200YNW-A1 Service Handbook page 149

[5-2 Outdoor Unit Control ]
5-2-8 Outdoor Unit Fan Control
(1) Control method
Depending on the capacity required, the rotation speed of the outdoor fan is controlled by the inverter to keep a constant con-
densing temperature (outside temperature + 10°C [50°F]) during cooling operation and a constant evaporation temperature
(0°C [32°F] = 0.71 MPa [103 psi]) during heating operation.
(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.
Both fans operate on the (E)M350, (E)M400, (E)M450, and (E)M500 models of outdoor units.
(3) Outdoor heat exchanger capacity control pattern
Outdoor fan rotation control is supported.
As the operation pattern number increases, the refrigerant bypassing the outdoor heat exchanger increases. As the operation
pattern number increases, the capacity difference becomes smaller between cooling operation and heating operation.
In each mode, the four-way valve and the expansion valve operate as shown in the table below. The expansion valve may
open or close during the refrigerant equalization control or the evaporation temperature control. See [5-2-9 Expansion valve
control (LEV2a, LEV2b, LEV2c, and LEV2d)]
Operation
Model
mode
(E)M200, Cooling-only
(E)M250, Cooling-main
(E)M300
models
Heating-only
Heating-main
Defrost
(E)M350, Cooling-only
(E)M400, Cooling-main
(E)M450
models
Heating-only
Heating-main
Defrost
(E)M500 Cooling-only
models Cooling-main
Heating-only
Heating-main
Defrost
(4) Evaporation temperature control (Expansion valves LEV2a, LEV2b, LEV2c, and LEV2d)
LEV is controlled every 30 seconds so that the minimum temperature of the liquid refrigerant (TH12) of the Cooling-main heat
exchanger and of the bypass inlet (TH15) of the HBC are in a constant range during Heating-only or Heating-main operation.
18
- chapter 5
Four-way valve
Operation
patterns
21S4a 21S4b
1 OFF OFF
2 OFF ON
3 OFF ON
4 OFF ON
1 ON ON
1 ON ON
2 ON ON
1 OFF OFF
1 OFF OFF
2 OFF ON
3 OFF ON
4 OFF ON
1 ON ON
1 ON ON
2 ON ON
1 OFF OFF
1 OFF OFF
2 OFF ON
3 OFF ON
4 OFF ON
1 ON ON
1 ON ON
2 ON ON
1 OFF OFF
21S4c LEV2a LEV2b
- 3000 3000
- 3000 41
- 500 41
- 300 41
- 3000 3000
- 3000 3000
- 3000 3000
- 3000 3000
- 3000 3000
- 3000 41
- 3000 41
- 1000 41
- 3000 3000
- 3000 3000
- 3000 3000
- 3000 3000
OFF 3000 3000
ON 3000 41
ON 3000 41
ON 1000 41
ON 3000 3000
ON 3000 3000
ON 3000 3000
OFF 3000 3000
LEV
LEV2c LEV2d LEV4
- 41 *Injection
controlled
- 1000
- 3000
- 3000
- 41
- 41
- 1250
- 41
- 20
- 800
- 6000
- 6000
- 20
- 20
- 1000
- 20
3000 20
41 800
41 6000
41 6000
3000 20
3000 20
3000 1000
3000 20
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