Low Pressure Protection Control - Daikin RXYQ72 Serivce Manual

Protection Control
4.2

Low Pressure Protection Control

This low pressure protection control is used to protect compressors against the transient decrease
of low pressure.
[In cooling operation]
Low pressure not limited
Pe<50 psi
Low pressure limited
All STD compressors
Pe<36 psi
Master unit:52 Hz + OFF
Slave unit:Stop
Pe<10 psi
[In heating operation]
Pe<23 psi
124 Hz + OFF
Pe<23 psi
Pe<19 psi
52 Hz + OFF
50
Pe>58 psi
stop.
Low pressure standby
Low pressure not limited
Low pressure limited
Low pressure standby
Pe: LP pressure sensor detection
When occurring 3 times within 30 min.,
the malfunction code " E4 " is output.
Pe >36 psi
&
INV upper limit frequency = 210 Hz
Pe>28 psi
Pe<10 psi
When occurring 3 times within 30 min.,
the malfunction code "E4" is output.
value for master unit
Pe: LP pressure sensor detection
value for each outdoor unit
INV upper limit frequency: 1-step /
20 sec up from current compressor
frequency
SiUS39-601
Function