Low Pressure Protection Control - Daikin SkyAir RZR-TA Series Service Manual

Protection Control
Heating operation
4.2

Low Pressure Protection Control

This low pressure protection control is used to protect compressors against the transient decrease
of low pressure.
Pe: Low pressure sensor detection value
Cooling
operation
118
Pc > 3.04 MPa (441 psi)
High pressure limited
After 10 sec.
Pc < 2.94 MPa (426 psi)
Low pressure not limited
Pe < 0.25 MPa
(36.3 psi)
Low pressure
limited
36 Hz Unload
Pe < 0.07 MPa
(10.2 psi)
Low pressure
standby
High pressure drop
High pressure not limited
Pc < 2.89 MPa (419 psi)
Compressor upper limit
frequency: 1-step down from
current compressor frequency
Pc > 3.04 MPa (441 psi)
Current step maintained
After 60 sec.
Compressor upper limit
frequency: 1-step up from
current compressor frequency
Pc > 3.64 MPa (528 psi)
High pressure
standby
Pe > 0.39 MPa
(56.6 psi)
Pe < 0.15 MPa
(21.8 psi)
When occurring 3 times within 30 minutes,
the error code E4 is output.
SiUS281811EA
When occurring 10 times within 60
minutes, high pressure switch is activated
without high pressure standby, thus
outputting the error code E3.
Hot gas bypass valve: OFF
Pe > 0.30 MPa
Hot gas bypass valve: ON
Part 4 Functions and Control
(43.5 psi)