Gree Dettson LOMO 19 Installation Manual page 75

2. IPM protection H5 , over-phase current of compressor P5
(AP1 hereinafter refers to the control board of the outdoor unit)
Main detection points:
(1) compressor COMP terminal (2) power supply voltage (3) compressor (4) charging amount of refrigerant (5) air inlet and air outlet
of indoor/outdoor unit
Malfunction diagnosis process:
Turn on the unit
after energization
Whether IPM
protection occurs after the unit has
operated for a while?
Y
Whether
the voltage between
terminal L and terminal N
of XT is within 210AVC~
250VAC?
Whether IPM
protection occurs after the unit has
operated for a while?
Y
1. Whether the heat exchangers of indoor unit and outdoor unit are
dirty? Whether the radiation is affected because the unit is
covered by the objects?
2. When indoor fan and outdoor unit are operate normally?
3. Whether the system pressure is too high?
4. Whether the pressure is because there's too much refrigerant?
Whether there's
abnormal phenomenons
described as above?
N
Whether the unit
can operate normally?
N
Y
Replace control
board
End
72
N
Correctly connect the wires of
compressor according to the
electric wiring diagram, and
then turn on the unit
Check the power
supply voltage and
N make the power voltage
resume to the range
of 210VAC~250VAC
Correct it one by one
according to the Service
Y
Manual, and then turn on
the unit.
Check the connection
between the control board
and the compressor by
referring to the electric
wiring diagram
Check whether wires
Y
of compressor (UVW) are connected
correctly
N
Measure the resistance value
among three terminals (UVW)
of compressor with a resistance
measuring meter.
Whether the
resistance value of three terminals
are almost the same.
Y
Measure the resistance
between three terminals (UVW)
of compressor and the copper pipe
with resistance measuring meter
Whether the
resistance value is more than
500ohm?
N
N
Replace the
compressor
Y
Y
Service Manual
Installation and Maintenance