Protection Control; High Pressure Protection Control - Daikin FCQ18PVJU 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 > 505 psi
High pressure limited
Pc < 490 psi
INV. upper limit frequency:
1-step up from current
compressor frequency
[In heating operation]
High pressure not limited
Pc > 469 psi
High pressure
limited
29
High pressure not limited
or
INV. upper limit frequency :
1-step down from current
compressor frequency
Every 10 sec. Pc > 512 psi
Keeping the current step
490 psi≤Pc≤505 psi
Every 60 sec.
Pc>547 psi
High pressure
standby
High-pressure drop
Pc < 441 psi
57Hz
Pc > 527 psi
High pressure
standby
• INV. upper limit frequency
&
• Pc ≤ 483 psi
• During oil return operation
• After oil return operation
• Stopping operation
• Heating operation
Every
5 min.
INV. upper limit frequency:
1-step up from current
compressor frequency
When occurring 3 times within 30
minutes, HPS is activated without high
pressure standby, thus outputting the
E3
malfunction code "
Pc: HP pressure sensor detection value
When HPS is activated, the
E3
malfunction code " " is output.
Pc: HP pressure sensor detection value
Pc > 526 psi
10 sec.
".
SiUS28-902_a
57Hz
Function