Trane TVR Pro CO Series Service Manual page 96

2.18 P2, H5: Suction pipe low pressure protection
Digital display output
Description
 All units stop running.
 Error code is only displayed on the unit with the error.
Trigger / recover condition
 Trigger condition:
For P2 protection: Suction pressure ≤ 0.05MPa.
For H5 protection: P2 protection appears three times in 60 minutes.
 Recover condition: Suction pressure ≥ 0.15MPa.
 Reset method:
For P2 protection: Resume automatically.
For H5 protection: Manually restart.
Possible causes
 Outdoor unit stop valves are closed.
 Insufficient refrigerant.
 Low pressure side blockage.
 Poor evaporator heat exchange.
 Main PCB damaged.
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