Midea V6 Series Service Manual page 122

2.22 P4, H6: Discharge temperature protection
2.22.1 Digital display output
2.22.2 Description
 Discharge temperature protection.
 All units stop running.
 Error code is only displayed on the unit with the error.
2.22.3 Trigger / recover condition
 Trigger condition:
For P4 protection: Discharge temperature (T7C1/2) ≥ 120
For H6 protection: P4 protection appears three times in 100 minutes.
 Recover condition: Discharge temperature (T7C1/2) ≤ 90
 Reset method:
For P4 protection: Resume automatically.
For H6 protection: Manually restart.
2.22.4 Possible causes
 Outdoor unit stop valves are closed.
 Temperature sensor/switch not connected
properly or has malfunctioned.
2.22.5 Procedure
ODU stop valves are closed
Compressor top temperature sensor,
discharge pipe temperature sensor
and/or discharge temperature switch
connections on main PCB are loose
Compressor top temperature sensor
and/or discharge pipe temperature
sensor have short circuited or failed
... flowchart continued from previous page
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P4 / H6
No
1
No
2
No
o
C.
o
C.
 Insufficient refrigerant.
 System blockage.
 Indoor load too large.
Yes
Open the stop valves
Ensure the sensors and switch are
Yes
connected properly
Yes
Replace the faulty sensor(s)
Flowchart continued on next page ...
V6 VRF 50Hz
 System contains air or nitrogen.
 Poor condenser heat exchange.
 Main PCB damaged.
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