Daikin VRV RXYQ72-384XAYCA, Service Manual

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SiUS342004EB Protection Control
Part 4 Functions and Control 96
6.2 Low Pressure Protection Control
This low pressure protection control is used to protect compressors against the transient decrease
of low pressure.
Cooling
Heating
N ormal control
All compressors step: 1
Pe < 0.15 MPa
(21. 8 psi)
Pe < 0.25 MPa
(36.3 psi)
Pe > 0.39 MPa
(56.6 psi)
Pe < 0.07 MPa (10.2 psi)
Pe: Lo w pressure sensor
detection value for master
unit
Master unit: Compressor step: 1
Slave unit: All stop
Abnormal stop
( E4 is displayed)
Lo w pressure standby
(3 times w ithin 60 minutes)
Lo w pressure standby
(4 times w ithin 60 minutes)
Normal control
9-step down 9-step u p
3-step u p 21-step down
After 10 seconds After 15 seconds
After 15 seconds After 10 seconds
Pe < 0.07 MPa
(10.2 psi)
Pe < 0.04 MPa
(5.8 psi)
Pe > 0.12 MPa
(17.4 psi)
Pe > 0.09 MPa
(13.1 psi)
Pe < 0.07 MPa
(10.2 psi)
Pe < 0.06 MPa
(8.7 psi)
Compressor step: 1
After 10 seconds
Upper limit compressor step: max (Max. Step)
Pe < 0.03 MPa
(4.35 psi)
Pe: Low press u re sensor
detection v al u e for each
o u tdoor u nit
C u rrent step
maintained
A b normal stop
( E4 is displayed)
Low press u re stand b y
(3 times within 60 min u tes)
Low press u re stand b y
(4 times within 60 min u tes)