Daikin VRV II RXYQ5MATL, Service Manual, Page: 97 / 331

Protection Control Si39-504
86 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 the case of multi-outdoor-unit system, each outdoor unit performs this control
individually in the following sequence.
[In heating operation]
In the case of multi-outdoor-unit system, the entire system performs this control in the
following sequence.
High pressure not limited
Pc>3.47MPa
High pressure standby
INV upper limit frequency = 210 Hz
High pressure limited
Pc>3.47MPa
Pc>3.64MPa
Pc<3.24MPa
Pc>3.55MPa
STD compressor
standby for 5 mins
Pc: HP pressure sensor detection
value for each outdoor unit
When occurring 3 times within
30 min., HPS is activated without high
pressure standby, thus outputting the
malfunction code “E3”.
INV upper limit frequency :
3-step / 10 sec down from
current compressor frequency
INV upper limit frequency:
1-step / 15 sec up from
current compressor frequency
High pressure not limited
Pc>3.32MPa
System load down 7 steps
High pressure limited
Pc>3.32MPa
Master unit: 52 Hz + OFF + OFF
Slave unit: All units stop.
Pc>3.42MPa
High pressure standby
Pc>3.64MPa
Pc<2.9MPa
Pc: HP pressure sensor detection
value for master unit
When occurring 3 times within
30 min., HPS is activated without high
pressure standby, thus outputting the
malfunction code “E3” .