V6R VRF 50Hz
40
Midea V
6
R
Series S
er
vice M
anual
6.7 Wet Compression Protection Control
This protection is used to prevent compressor from damaging for the long time wet compression so that it can’t be lubricated
well. This control is performed for each compressor.
Figure 3-6.10:
Wet compression protection control
Notes:
1.
DSH: Superheat of discharge temperature
6.8 High Pressure Ratio Protection Control
This high pressure ratio protection control is used to prevent the activation of protection devices due to abnormal increase
of high pressure ratio, and to protect compressors against the transient increase of high pressure ratio. It is performed for
entire system.
Figure 3-6.11:
High pressure ratio protection control
Notes:
1.
P
c
: Discharge pressure P
e
: Suction pressure
2.
Pressure Ratio = (Pc+0.10)/(Pe+0.10)
DSH < 6°C for more than 60minutes
DSH
≥
10°C for more than 10minutes
Normal operation
Wet compression protection, error code
PP is displayed
High pressure ratio
≥
8.5
High pressure ratio < 7.5
Normal operation
High pressure ratio protection,
compressor frequency is limited
