2.20 P2, H5: Suction pipe low pressure protection
Description
ï‚§ All units stop running.
ï‚§ Error code is displayed on the unit with the error.
Trigger / recover condition
ï‚§ Trigger condition:
For P2 protection: Suction pressure < 0.07MPa.
For H5 protection: P2 protection appears three times in 60 minutes.
ï‚§ Recover condition:
 Cooling Only/Main Cooling Discharge pressure ≥ 0.23MPa and Restart permission=ON.
 Heating Only/Main Heating Discharge pressure ≥ 0.18MPa and Restart permission=ON.
ï‚§ Reset method:
For P2 protection: Resume automatically.
For H5 protection: Manually restart.
Possible causes
ï‚§ Outdoor unit stop valves are closed.
ï‚§ Insufficient refrigerant.
ï‚§ Low pressure side blockage.
ï‚§ Poor evaporator heat exchange.
ï‚§ Outdoor main PCB damaged.