Protection Control; High Pressure Protection Control - Daikin R410As Service Manual

Si39-302
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]
#
Pc>3.48MPa
INV upper limit frequency :
3-step / 10 sec down from
current compressor frequency
Pc>3.48MPa
Pc>3.53MPa
STD compressor
standby for 5 mins
[In heating operation]
#
Pc>3.38 MPa
Lower-priority compressor stops.
Pc>3.38 MPa
Pc>3.49 MPa
Master unit: 52 Hz + OFF + OFF
Slave unit: All units stop.
Function
In the case of multi-outdoor-unit system, each outdoor unit performs this control
individually in the following sequence.
High pressure not limited
INV upper limit frequency = 210 Hz
High pressure limited
Pc>3.58MPa
High pressure standby
In the case of multi-outdoor-unit system, the entire system performs this control in the
following sequence.
High pressure not limited
Pc<3.0 MPa
High pressure limited
Pc>3.58 MPa
High pressure standby
Pc: HP pressure sensor detection
value for each outdoor unit
Pc<3.2MPa
INV upper limit frequency:
1-step / 20 sec up from
current compressor frequency
When occurring 3 times within
30 min., HPS is activated without high
pressure standby, thus outputting the
malfunction code "E3" .
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" .

Protection Control

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