Protection Control; High Pressure Protection Control - Daikin REYQ-XA Service Manual

Protection Control

6. Protection Control
6.1

High Pressure Protection Control

This high pressure protection control is used to prevent the activation of protection devices due to
abnormal increase of high pressure and to protect compressors against the transient increase of
high pressure.
Cooling
21-step down
Pc > 3.67 MPa
(532 psi) After 10
seconds
9-step down
Pc > 3.62 MPa
(525 psi)
Pc > 3.57 MPa
(518 psi)
2-step down
Pc > 3.70 MPa
(537 psi)
117
Upper limit compressor step: max (Max. Step)
Normal control
Pc > 3.57 MPa
(518 psi)
2-step down
After 10 seconds After 15 seconds
Pc < 3.33 MPa (483 psi)
Current
step
maintained
After 15 seconds
After 10 seconds After 15 seconds
After 10 seconds
Compressor step: 1
Pc > 3.72 MPa
(540 psi)
High pressure standby
(2 times within 40 minutes)
9-step up
Pc < 3.14 MPa
(455 psi)
3-step up
Pc < 3.45 MPa
(500 psi)
1-step up
High pressure switch (4.0 MPa
(580 psi)) is activated
Abnormal stop
(E3 is displayed)
SiUS371901E
Pc: High pressure sensor
detection value for each
outdoor unit
Functions and Control