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 in cooling operation
Notes:
1. P
c
: Discharge pressure
Figure 3-6.2: High pressure protection control in heating operation
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 3-6.3: Low pressure protection control in cooling operation
Notes:
1. P
e
: Suction pressure
High pressure protection, error code P1 is displayed
High pressure protection, error code P1 is displayed
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.