Mitsubishi Electric City Multi PQHY-P72 Service Handbook page 145

[ VII Control ]
-9- Subcool Coil Control (Linear Expansion Valve <LEV1>) <PQHY>
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 pressure (Pd), and
discharge temperature. 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.
-10- Control at Initial Startup <PQHY/PQRY>
When the unit is started for the first time, it will run the following course of operation.
(1) Flow chart of initial operation mode
The unit does not go into the initial operation mode when twelve hours have elapsed after power on.
(2) Restrictions during initial heating startup mode
When the compressor discharge SH is small or the discharge pressure is low in heating only, heating main, or cooling
main mode, the total capacity of operable outdoor unit will be restricted. (Only when there are four or more indoor units
in heating operation)
[Total capacity of operable indoor units]
The number of connected indoor units is 5 or more: P34 model or below
The number of connected indoor units is 4 or less: P53 model or below
Before twelve hours have elapsed after power on
Start of initial operation mode
f 50 Hz.
Completed in the continuous integrated operation time of 20
minutes and integrated operation time of 30 minutes, or in the
integrated operation time of 90 minutes
Exception: completed if discharge super heat reaches above
45 C[113 F] during the initial start-up mode
Completion of initial operation
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