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[5-2 Outdoor Unit Control ]
5-2-9
Expansion valve control (LEV2a, LEV2b, LEV2c, and LEV2d)
The default opening levels of the expansion valves LEV2a, LEV2b, LEV2c, and LEV2d are shown in Section [5-2-8 Outdoor
Unit Fan Control]. When the following control (1) is performed during heating-only or heating-main operation, the valves open
or close.
(1) Evaporation temperature control
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.
5-2-10
Control of Controller Cooling Function (Electronic Expansion Valve <LEV9>)
Control of controller cooling function is performed individually for OC.
The opening of LEV9 is adjusted every three seconds to keep the controller heatsink temperature (THHS) below the threshold
value, which is determined by the setting of the outside temperature (TH7).
5-2-11
Injection Control (Linear Expansion Valve <LEV4>)
LEV4 opening is adjusted every 30 seconds to keep the discharge temperature (TH4) within the predetermined range.
5-2-12
Control at Initial Startup
When started up for the first time before 12 hours have elapsed after power on, the unit goes into the initial startup mode.
They will go into the normal control mode.
(1) Single-outdoor-unit system
BS_05_M
Initial startup mode starts.
Completed when one of the following three
conditions is met.
50 ≤ F ≤ 60Hz
Completed when the integrated operation time
reaches 35 minutes.
F < 50Hz
Completed when the integrated operation time
reaches 90 minutes.
Completed if the cumulative compressor
operation time exceeds 120 minutes within 5
minutes of startup, and the discharge superheat
(TH4-Tc) of approximately 25 degrees or above is
registered for one continuous minute.
Initial startup mode complete
19
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