Daikin REYQ-AATJA, Service Manual

Page: 146 / 495

Protection Control SiUS372201EA
139 Part 4 Functions and 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
Normal control
21-step down 9-step up
9-step down 3-step up
2-step down
1-step up
2-step down
After 10 seconds After 15 seconds
After 15 seconds After 10 seconds
Pc > 3.57 MPa
(518 psi)
Pc > 3.70 MPa
(537 psi)
Pc < 3.14 MPa
(455 psi)
Pc < 3.43 MPa
(498 psi)
Pc > 3.67 MPa
(532 psi)
Pc > 3.62 MPa
(525 psi)
Pc > 3.57 MPa
(518 psi)
Compressor step: 1
After 15 seconds
Pc < 3.32 MPa (481 psi)
After 10 seconds
Upper limit compressor step: max (Max. Step)
Pc > 3.72 MPa
(540 psi)
Pc: High pressure sensor
detection value for each
outdoor unit
Current
step
maintained
Abnormal stop
( E3 is displayed)
High pressure standby
(2 times within 40 minutes)
After 10
seconds
High pressure switch (4.0 MPa
(580 psi)) is activated