intensity VRF V5 Series Service Manual page 82

V5 X VRF 460V 60Hz
4.14 P0, P4, H6 Troubleshooting
Digital display output
Description
 P0 indicates compressor temperature protection.
 P4 indicates discharge temperature protection. When the discharge temperature rises above 120°C the system
displays P4 protection and all units stop running.
 H6 indicates P4 protection has occurred 3 times in 100 minutes. When an H6 error occurs, a manual system restart is
required before the system can resume operation.
 Error code is only displayed on the unit with the error.
Possible causes
 Outdoor unit stop valves are closed.
 Temperature sensor/switch not connected
properly or has malfunctioned.
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
80
P0 / P4 / H6
No
1
No
2
No
 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 ...
 System contains air or nitrogen.
 Poor condenser heat exchange.
 Main PCB damaged.