Mitsubishi Heavy Industries SRK20MA-S User Manual

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Error of outdoor unit (Damage of power transistor, wiring break of compressor)
Compressor over heat (Insufficient refrigerant, failure of discharge pipe sensor)
Power cut (Open-phase of output terminal of compressor, compressor lock)
Has all three-phase output voltage
been applied to the power transistor?
No
Failure of inverter
No
Yes
Yes
Has the wiring for the compressor
been properly connected?
Connect it properly.
Check the compressor.
No
No
No
Yes
Yes
Is the resistance value of the
discharge pipe sensor normal?
Check that the connection of the connector is
correct; check the resistance value; replace
the discharge pipe sensor.
Yes
Is the refrigerant circulating load
normal?
Is the situation the same after
refrigerant is charged?
Insufficient
refrigerant
Failure of inverter
Blockage of hush pipe, etc.
No
No
No
Yes
Yes
Yes
Disconnect the wiring of the compressor and
operate the inverter to check whether the
power cut function does not work.
Failure of inverter
Failure of inverter
Has all three-phase output voltage been
applied to the power transistor?
Whether there is no short circuit?
Check the compressor.
Ensure the space of air suction and air blowing.
Visually inspect wiring of compressor
Check insulating resistor (above 1MΩ)
Check winding coil resistor (about several Ω)
In normal cases, the
compressor is locked.

Mitsubishi Heavy Industries SRK20MA-S Specifications

General

Brand	Mitsubishi Heavy Industries
Model	SRK20MA-S
Category	Air Conditioner
Language	English