Midea V4+R Series - Protection Control

V4+R VRF 50/60Hz
32 201702
Midea V4+R Series Service Manual
6 Protection Control
6.1 High Pressure Protection Control
This control protects the system from abnormally high pressure and protects the compressors from transient spikes in
pressure.
Figure 3-6.1: High pressure protection control
Notes:
1. P
c
: Discharge pressure
6.2 Low Pressure Protection Control
This control protects the system from abnormally low pressure and protects the compressors from transient drops in
pressure.
Figure 3-6.2: Low pressure protection control
Notes:
1. P
e
: Suction pressure
6.3 Discharge Temperature Protection Control
This control protects the compressors from abnormally high temperatures and transient spikes in temperature. It is
performed for each compressor.
Figure 3-6.3: Discharge temperature protection control
When the discharge temperature rises above 120°C the system displays P4 protection and all units stop running. When P4
protection occurs 3 times in 100 minutes, the H6 error is displayed. When an H6 error occurs, a manual system restart is
required before the system can resume operation.
P
c
> 4.4MPa
P
c
< 3.2MPa
Normal operation
High pressure protection, error code P1 is displayed
P
e
< 0.05MPa
P
e
> 0.15MPa
Normal operation
Low pressure protection, error code P2 is displayed
When P2 protection occurs 3 times
in 60 minutes, the H5 error is
displayed. When an H5 error occurs,
a manual system restart is required
before the system can resume
operation.
120
o
C
100
o
C
90
o
C
Discharge temperature
Compressor off
SV2 off
SV2 on
90
o
C