Mitsubishi Electric PUHY-P200 Service Handbook page 75

(3) Patterns of outdoor unit heat exchanger capacity control
[P200-P350types]
Operation Heat exchanger
mode capacity
50%
Cooling
100%
Heating 100%
Defrost 100%
Note 1 : 21S4b and 21S4c are not energized during cooling cycle and energized during heating cycle.
Note 2 : SV5b and SV5c are not energized when it is open and energized when it is closed.
Note 3 : While the unit is stopped, 21S4b and 21S4c are not energized and in cooling cycle, and SV5b and SV5c are opened.
8. Subcool coil control (Linear expansion valve <LEV1>)
• The amount of super heat is controlled and kept constant based on the bypass outlet temperature (TH8) of
subcool coil every 30 seconds.
• The degree of opening is controlled based on the subcool coil outlet/inlet temperature (TH5, TH7), high pres-
sure (Pd), and discharge temperature.
However, the LEV will be closed (0) during heating operation and when the compressor is stopped, and it will
be open during cooling operation with thermo off.
• It stays open at 480 during defrost operation.
9. Control at initial startup
• If the unit is started within 2 hours of power on when the outdoor temperature is below a certain degree
(below 5˚C for cooling operation and below -5˚C for heating operation), the unit will be on the stand-by mode
and will not start for 30 minutes after power on. (P200 type only)
• When the unit is started for the first time, it will run the following course of operation.
Flow chart of initial operation mode
Step 1
• Operation of only No.1 compressor
P200
P250~P400
P450~P650
Exception : completed if discharge super heat reaches above
Step 3
• Forced operation of only No.2 compressor
• Completed in the integrated operation time of 5 minutes
[P400-P650types]
Inverter Operation
Remarks
control mode
21S4b ON
5~100%
SV5b ON
21S4b OFF
10~100%
Cooling
SV5b OFF
21S4b ON
10~100%
SV5b OFF
21S4b OFF
0%
Heating
SV5b OFF
Defrost
Start of initial operation mode
: f 50Hz and completed in the continuous integrated operation time
of 20 minutes or the integrated time of 90 minutes.
: f 60Hz and completed in the continuous integrated operation time
of 20 minutes or the integrated time of 90 minutes.
: For the first 30minutes f
No.2 compressor not in operation.
Completed in the integrated operation time of 40 minutes.
5 minutes of start up.
P450~P650 types
Completion of initial operation
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Heat exchanger Number Inverter
capacity of fans control
25% 1 5~100%
50% 1 10~100%
100% 2 15~100%
100% 2 10~100%
100% 0 0%
60Hz, 30minutes and on f
25˚C
P200~P400 type
Remarks
21S4b, 21S4c ON
SV5b, SV5c ON
21S4b ON, 21S4c OFF
SV5b ON, SV5c OFF
21S4b, 21S4c OFF
SV5b, SV5c OFF
21S4b, 21S4c ON
SV5b, SV5c OFF
21S4b, 21S4c OFF
SV5b, SV5c OFF
85Hz.
within