Low Pressure Protection Control - Daikin D-Series Service Manual

Protection Control
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
<
Pe 0.25MPa
Low pressure
limited
In heating operation
• Pe>0.25MPa
& • INV upper limit
frequency
Low pressure limited
Pe>0.19MPa(every 20 sec.)
SVP = OFF
122
Low pressure not limited
>
Pe 0.4MPa
52Hz
Pe < 0.07MPa
Low pressure
standby
Low pressure not limited
Upper limit:
124Hz
Pe<0.13MPa
Upper limit:
52Hz
Pe>0.19MPa
Upper limit: 1-step up from
current compressor frequency
Pe>0.17MPa
Pe<0.10MPa
Low pressure
standby
Pe: LP pressure sensor detection
value
SVP=OFF
< >
Pe 0.15MPa Pe
SVP=ON
When occurring 3 times within 60 min.,
the malfunction code "E4"
Pe<0.16MPa
More than 124Hz
&
Pe<0.16MPa
Pe<0.13MPa
SVP = ON
Pe < 0.07MPa
When occurring 3 times within 60 min.,
the malfunction code "E4"
0.30MPa
is output.
Pe: LP pressure sensor detection
value
is output.
Si18-525B
(Q0376)
(V3176)
Function