Mitsubishi Electric MXZ-2E53VAHZ, Service Manual

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The other cases
• When the operation frequency does not go up from the lowest frequency.
Check of bus-bar voltage
•Check the voltage of power supply.
•Con fi rm outdoor unit failure mode
recall function. (Refer to 11-2.2.)
Blink 5 times
Con fi rm LED1 indication lamp on the
outdoor control P.C. board.
Replace the outdoor power
P.C. board.
Blink 9 times
Replace the outdoor control
P.C. board.
Turn OFF power supply before removing P.C. board.
Con fi rm LED1 indication lamp
on the outdoor control P.C.
board.
Turn ON power supply. Start
operation.
Lighting
Replace the outdoor control
P.C. board.
Blink 9 times
Replace the outdoor power
P.C. board.
Con fi rm LED1 indication lamp
on the outdoor control P.C.
board.
Turn ON power supply. Start
operation.
Normal
Lighting Lighting
Check of HPS
Infinity
Ÿ
No
Yes
1. Disconnect the connector CN63H in the outdoor control P.C. board.
2. Check the resistance of HPS after 1 minute has passed since the outdoor unit power supply was turned OFF.
Check the resistance between each terminal.
Reconnect CN63H.
Turn ON the power supply to the indoor and outdoor unit.
3 minutes later, start EMERGENCY OPERATION.
Is HPS protection displayed immediately
after compressor starts?
Replace HPS.
Replace the outdoor control P.C. board.
Normal
CN63H
Outdoor control
P.C. board
Indoor unit does not operate. (different operating models in multi system)
• When you try to run 2 indoor units simultaneously, one for cooling and the other for heating, the unit which transmits signal to
the outdoor units fi rst decides the operation mode.
• When the above situation occurs, set all the indoor units to the same mode, turn OFF the indoor units, and then turn them back
ON.
• Though the top of the indoor unit sometimes gets warm, this does not mean malfunction. The reason is that the refrigerant gas
continuously fl ows into the indoor unit even while it is not operating.
OBH723C