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SiBE18-821_C
Protection Control
Function
89
4.2
Low Pressure Protection Control
This low pressure protection control is used to protect compressors against the transient
decrease of low pressure.
[In cooling operation]
[In heating operation]
Pe
<
0.25 MPa
36Hz Unload
Pe
>
0.39 MPa
Pe
<
0.07 MPa
Low pressure not limited
Pe < 0.15 MPa
Pe > 0.30 MPa
Hot gas bypass valve = OFF
Hot gas bypass valve = ON
(R12928)
Low pressure
limited
Pe: Low pressure sensor detection value
Low pressure
standby
When occurring 3 times within 30 min.,
the error code "
E4
" is output.
&
Ts – Teg < 8 deg
Pe > 0.06 MPa
Pe > 0.09 MPa
or
After 10 sec.
Pe < 0.17 MPa
Pe < 0.17 MPa
Pe > 0.20 MPa
Pe
<
0.07 MPa
Current step limited
After 15 sec.
Low pressure not limited
Low pressure limited
Pe < 0.12 MPa
Pe > 0.17 MPa
Hot gas bypass valve = OFF
Hot gas bypass valve = ON
(R12929)
Upper limit frequency:
3-step down from current
compressor frequency
Upper limit frequency:
1-step up from current
compressor frequency
Low pressure
standby
When occurring 3 times within 30 min.,
the error code "
E4
" is output.
Pe: Low pressure sensor detection value