Toyotomi MTN-MTG 256DV Service Manual page 36

10.2.8 P1(over voltage or too low voltage protection) diagnosis and solution.
Is the power supply good?
YES
10.2.9 P2(temperature protection of compressor top) diagnosis and solution.
Does compressor
operate?
YES
Is refrigerant
circulation
volume normal?
NO
Charge refrigerant
Is abnormality
the same after
gas charging?
NO
10.2.10 P4(inverter compressor drive error) diagnosis and solution.
Is the connection of
compressor good? Is the
wiring sequence right? The
voltage range proper?
YES
Replace the outdoor E-box.
If the problem comes to
again, check coil resistance
of inverter compressor, is it
right?
NO
Is the connection
good?
YES
Is protector
normal?
YES
Check the outdoor
main PCB. Is there
some problem?
YES
NO
Be sure the power supply is
normal when using the units
Replace the outdoor e-box.
NO
NO
NO
NO
Reconnect and retest.
Replace the protector.
Replace the outdoor PCB.
Check refrigerant system (such as
clogging of capillary, etc)
Reconnect and retry
Replace inverter compressor
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