Mitsubishi Electric PU-P71VHA Service Manual page 58

<Display function of inspection for outdoor unit>
• The blinking patterns of two LEDs—LED1(Green) and LED2(Red)—show the diagnoses of troubles in case of malfunction.
• By 7SEG indicator board indicates the operation mode and inspection types.
Indication (O.B)
LED1 LED2
(Green) (Red)
1 blink •Negative Phase detection
1 blink
•The wires of power supply and connecting
wires of indoor / outdoor units are crossed
with one another.
2 blinks
•51CM connector open
•63L connector open
2 blinks 1 blink •Indoor / outdoor unit connector mis-wiring
•Excessive numbers of indoor units per an
outdoor unit (five or more)
•Mis-wiring of indoor / outdoor unit connection
wires (crossed wiring or disconnection)
•Start-up time is up
2 blinks •Indoor / outdoor unit transmission error
(Signal receiving error: Indoor controller side)
•Indoor / outdoor unit transmission error
(Transmitting error: Indoor controller side)
•Indoor / outdoor unit transmission error
(Signal receiving error :Outdoor controller side)
•Indoor / outdoor unit transmission error
(Transmitting error: Outdoor controller side)
3 blinks •Remote controller transmission error
(Signal receiving error: Remote controller side)
•Remote controller transmission error
(Transmitting error: Remote controller side)
•Remote controller transmission error
(Signal receiving error: Indoor controller side)
•Remote controller transmission error
(Transmitting error: Indoor controller side)
4 blinks •Undefined error code
Error Name
LED1 (Green)
LED2 (Red)
Inspection method
1 Check if the wires of power supply are connected to their
corresponding terminals on TB1.
2 Check if the wirings are correct on power supply (TB1) and
outdoor power supply board (TB2).
1 Check if the connectors of 51CM (51C) on
outdoor controller board are disconnected.
2 Check the continuity of connector 51CM (51C) by using a
tester.
1 Check connection of 63L(63L) connector on outdoor
controller board.
2 Check the 63L side of connecting wire.
3 Check refrigerant pressure.
Charge additional refrigerant.
Check continuity by tester.
Replace outdoor controller board.
4 Replace outdoor controller board.
1 Check if the wirings are correct on the connecting wires of
indoor / outdoor units.
2 Check if a single outdoor unit connects five or more indoor
units.
1 Check if the wirings are correct on the connecting wires of
indoor / outdoor units.
2 Check if there is noise on the wires of power supply and
connecting wires of indoor / outdoor units.
3 Check if there is noise on both indoor and outdoor
controller board.
4 Turn the power off and let the units operate again to confirm.
1 Check if the wirings are correct on indoor units or remote
controllers.
2 Check if there is noise on the transmission lines of remote
controllers.
3 Turn the power off and let the units operate again to confirm.
1 Check if there is noise on the transmission lines of remote
controllers.
2 Check if there is noise on the connecting wires of
indoor/outdoor units.
3 Turn the power off and let the units operate again to confirm.
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To be continued on the next page.