Protection Control; High Pressure Protection Control - Daikin VRV III RXYQ5-54PY1 Service Manual

Protection Control

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>3.43MPa
INV upper limit frequency:
3-step down from current
compressor rps
(Slave unit: 3-step down as well)
Pc>3.43MPa
Pc>3.55MPa
STD compressor
standby
[In heating operation]
★
Pc>3.10 MPa
System load down 1 steps
Pc>3.10 MPa
Pc>3.49 MPa
EV1 opening adjustment
(Reducing low pressure to make
high pressure lower.)
118
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
After 10 sec.
Current step maintained
After 10 sec.
Pc>3.64MPa
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<2.9 MPa
After 10 sec.
Current step maintained
Pc<2.52MPa
Pc>3.64 MPa
High pressure standby
Pc: HP pressure sensor detection
value for each outdoor unit
= max
rps
INV upper limit
Pc<3.24MPa
1-step up from current
compressor frequency
(Slave unit: Same as above)
After 15 sec.
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
Pc<3.0MPa
INV upper limit
rps: 1-step up
After 60 sec.
When occurring 3 times within
30 min., HPS is activated without high
pressure standby, thus outputting the
malfunction code "E3" .
Si34-601A
:
frequency
Function