Mitsubishi Heavy Industries SCM40ZF-S User Manual

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99
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Rotor lock
[Compressor defect, outdoor
unit circuit defect]
Outdoor fan motor error
[Defective fan motor, connector
poor connection, defective PCB]
Is connector connection good?
YES
NO
NO
Is the output of the outdoor unit’s
printed circuit board normal?
Normal
NO
YES
YES
Correct connector connection
Is DC fan motor resistance value good?
Replace outdoor PCB
Replace outdoor fan motor
* Disconnect the fan motor
connector, then investigate
the DC fan motor and out-
door unit circuit board sepa-
rately.
(4) Phenomenon observed after shortcircuit, wire breakage on sensor
(a) Indoor unit
Phenomenon
Sensor
Shortcircuit Broken wire
Cooling Release of continuous compressor operation command
Heating Continuous compressor operation command is not released.
Compressor stop.
Cooling
(Abnormality of outdoor unit)
Heating High pressure control mode
Operation
mode
Room temperature
sensor
Continuous compressor operation command is not released.
Release of continuous compressor operation command
Continuous compressor operation command is not released.
(Anti-frosting)
Hot keep (Indoor fan stop)
Heat exchanger
sensor
Drain abnormality (STM, SRRM only)
[Drain piping defective,
pump defect]
YES
Has an overflow developed?
Is the drain piping clogged or at
the wrong gradient?
Is the float switch operating?
Indoor printed circuit
board is defective.
Is there output for drain motor driver?
YES
YES
Drain motor is defective.
Inspect wiring.
Inspect float switch.
Repair and clean.
Indoor printed circuit board
is defective.
YES
NO
NO
NO
NO
NO
YES
● Check compressor wiring visually.
● Check insulation resistance. (1 MΩ or over)
● Check coil wire resistance. (Few Ω)
Is output voltage applied to all 3
phases of power transistor?
Inspect compressor.
Defective inverter
If check results are normal,
compressor is locked.

Mitsubishi Heavy Industries SCM40ZF-S Specifications

General

Brand	Mitsubishi Heavy Industries
Model	SCM40ZF-S
Category	Air Conditioner
Language	English