Wet Compression Protection Control; High Pressure Ratio Protection Control - Midea VRF Series Service Manual

V6R VRF 50/60Hz

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
DSH < 6°C for more than 60minutes
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.
40
Normal operation
Wet compression protection, error code
Figure 3-6.11: High pressure ratio protection control
Normal operation
High pressure ratio 8.5
≥
High pressure ratio protection,
compressor frequency is limited
Notes:
1. P : Discharge pressure P : Suction pressure
c e
2. Pressure Ratio = (Pc+0.10)/(Pe+0.10)
DSH 10°C for more than 10minutes
≥
PP is displayed
High pressure ratio < 7.5