Low Pressure Protection Control - Daikin RMXS-L Series Service Manual

Protection Control
4.2

Low Pressure Protection Control

Outline
Low pressure protection control is used to protect compressors against the temporary decrease of
low pressure.
<Cooling Operation>
Pe < 0.25 MPa (84 ftAq)
Low pressure
limited
Pe < 0.07 MPa (23 ftAq)
<Heating Operation>
Pe < 0.17 MPa (57 ftAq)
Low pressure limited
Pe < 0.17 MPa (57 ftAq)
Pe > 0.20 MPa (67 ftAq)
51
Low pressure not limited
Pe > 0.39 MPa (130 ftAq)
36 Hz Unload
Low pressure
standby
Low pressure not limited
Upper limit frequency: 3-step down
After 10 sec.
Current step limited
After 15 sec.
Upper limit frequency: 1-step up
Pe < 0.07 MPa (23 ftAq)
Low pressure
standby
Pe: Low pressure sensor detection value
Hot gas bypass valve = OFF
Pe < 0.15 MPa
(50 ftAq)
Hot gas bypass valve = ON
When occurring 3 times within 30 minutes,
the error code E4 is output.
Pe: Low pressure sensor detection value
Pe > 0.09 MPa (30 ftAq)
Ts1 – Te < 8˚C (14.4˚F)
or
&
Pe > 0.06 MPa (20 ftAq)
When occurring 3 times within 30 minutes,
the error code E4 is output.
SiUS181305E
Pe > 0.30 MPa
(100 ftAq)
(R19081)
Hot gas bypass valve = OFF
Pe < 0.12 MPa Pe > 0.17 MPa
(40 ftAq)
Hot gas bypass valve = ON
(57 ftAq)
(R19082)
Function