Daikin VRVIII-S, Service Manual

Page: 63 / 266

Protection Control SiENBE34-703
52 Function
4. Protection Control
4.1 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.
[In cooling operation]
[In heating operation]
Keeping the current step
When occurring 10 times within 60
minutes, HPS is activated without high
pressure standby, thus outputting the
malfunction code "E3".
INV upper limit frequency=Max
High pressure
standby
Pc>3.64MPa
INV upper limit frequency :
1-step up from current
compressor frequency
After 15 sec.
Pc<3.23MPa
Pc>3.47MPa After 10 sec.
INV upper limit frequency :
3-step down from current
compressor frequency
High pressure limited
Pc: HP pressure sensor detection value
High pressure not limited
Pc>3.47MPa
High-pressure drop
Pc>3.04MPa
Pc>3.64MPa
INV upper limit frequency :
1-step down from current
compressor frequency
When occurring 10 times within 60
minutes, HPS is activated without high
pressure standby, thus outputting the
malfunction code "E3".
Pc<2.89MPa
Pc: HP pressure sensor detection value
High pressure not limited
High pressure limited
Keeping the current step
INV upper limit frequency :
1-step up from current
compressor frequency
High pressure
standby
After 60 sec.
Pc<2.94MPa
Pc>3.04MPa
After 10 sec.