Low Pressure Protection Control - Daikin VRV-WIII RWEYQ72PTJU Service Manual

Protection Control
6.2

Low Pressure Protection Control

This low pressure protection control protects compressors against the transient decrease of low pressure.
[In cooling]
Pe: Value detected by low pressure sensor for master unit
Pe < 49.3 psi
Pe < 34.8 psi
Less than 3 times
within 60 minutes
1 This frequency control is carried out in whole system.
Note:
[In heating or simultaneous cooling/heating]
(When the condensing unit heat exchanger is used as evaporator.)
Pe: Value detected by low pressure sensor for each condensing unit
Pe < 91.3 psi
Pe < 79.7 psi
Less than 3 times
within 60 minutes
1 This frequency control is carried out in each condensing unit.
Note:
56
Normal operation
Pe > 56.5 psi
Compressor 52 Hz
Hot gas solenoid valve (Y1S)
ON
Pe < 10.1 psi
Low pressure standby
Normal control
Pe > 102.9 psi
Compressor upper limit down
1 step/10 seconds
Compressor 52 Hz
Pe < 10.1 psi
Low pressure standby
Pe > 49.3 psi
Hot gas solenoid valve (Y1S)
Pe < 34.8 psi
When occurring 4 times within 60 minutes,
E4
the error code " " is displayed.
Pe > 98.6 psi
Compressor upper limit up
1 step/20 seconds
Pe < 91.3 psi
When occurring 4 times within 60 minutes,
E4
the error code " " is displayed.
SiUS30-1301
OFF
Function and Control