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DIAGNOSIS AND SOLUTION (CONT)
Inverter compressor drive error diagnosis and solution (P4)
Error Code
P4
Malfunction decision conditions
An abnormal inverter compressor drive is detected by a special detection circuit, including
communication signal detection, voltage detection, compressor rotation speed signal detection, etc.
Supposed causes
S
Wiring mistake
S
IPM malfunction
S
Outdoor fan assembly faulty
S
Compressor malfunction
S
Outdoor PCB faulty
Troubleshooting
Check the wiring between main PCB
and compressor
Correct the connection or replace
the wires and connectors.
Yes
No
Check the IPM
No
Yes
Replace the IPM board or replace
the main PCB
Check the outdoor fan and the
outdoor unit ventilation
No
Please refer to the solution of
Ǐ
Fan
Speed Has Been Out Of Control
ǐ
malfunction
Yes
Check the compressor resistance
values
No
Replace the compressor.
Yes
Replace the outdoor main PCB
Summary of Contents for 38MHRB series
Page 7: ...7 DIMENSIONS OUTDOOR CONT Unit inch mm Fig 3 Size 24K...
Page 11: ...11 WIRING DIAGRAMS COOLING ONLY Fig 7 Wiring Diagram Size Cooling Only Size 12K 115V...
Page 12: ...12 WIRING DIAGRAMS COOLING ONLY CONTINUED Fig 8 Wiring Diagram Cooling Only Size 12K 230V...
Page 13: ...13 WIRING DIAGRAMS COOLING ONLY CONTINUED Fig 9 Wiring Diagram Cooling Only Sizes 18 24K...
Page 14: ...14 WIRING DIAGRAMS HEAT PUMP Fig 10 Wiring Diagram Heat Pump Size 12K 115V...
Page 15: ...15 WIRING DIAGRAMS HEAT PUMP CONTINUED Fig 11 Wiring Diagram Heat Pump Sizes 09 12 18 230V...
Page 16: ...16 WIRING DIAGRAMS HEAT PUMP CONTINUED Fig 12 Wiring Diagram Heat Pump Size 24 230V...
Page 37: ...37 DIAGNOSIS AND SOLUTION CONT Fig 36 P U Fig 37 P V...
Page 38: ...38 DIAGNOSIS AND SOLUTION CONT Fig 38 P W Fig 39 N U...
Page 39: ...39 DIAGNOSIS AND SOLUTION CONT Fig 40 N V Fig 41 N W...
