Daikin VRV EMERION RXYQ-AATJA, Service Manual

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SiUS342303E Protection Control
Part 4 Functions and Control 112
6.2 Low Pressure Protection Control
This low pressure protection control is used to protect compressors against the transient decrease
of low pressure.
Cooling
Because of common low pressure, the following control is performed in the system.
Heating
The following control is performed in the system.
6.3 Discharge Pipe Protection Control
This discharge pipe protection control is used to protect the compressor internal temperature
against an error or transient increase of discharge pipe temperature.
HTdi: Value of compressor discharge pipe temperature (Tdi) compensated with outdoor air
temperature
Ti: Compressor body temperature
A: Maximum of HTdi and Ti
The following control is performed for each compressor of single unit as well as multi units.
Normal control
Low pressure standby
Reduce compressor capacity step
When occurring 3 times within 60
minutes, the error code
E4 is output.
Pe: Low pressure sensor detection
value for master unit.
Pe < 0.25 MPa
(36.3 psi)
Pe > 0.39 MPa
(56.6 psi)
Pe < 0.07 MPa
(10.2 psi)
Normal control
Low pressure standby
Reduce compressor capacity step
When occurring 3 times within 60
minutes, the error code
E4 is output.
Pe < 0.05 MPa
(7.3 psi)
Pe > 0.1 MPa
(14.5 psi)
Pe < 0.02 MPa
(2.9 psi)
Normal control
HTdi > 135°C
(275°F)
A > 108°C
(226°F)
Reduce compressor capacity step
Discharge pipe temperature standby
When occurring 3 times within 100
minutes, the error code
F3 is output.
(Sub code - 01, 02, 03)
A < 95°C
(203°F)