Service Manual
(2) IPM Protection, Out-of-step Fault, Compressor Phase Overcurrent (AP1 below refers to the outdoor control
panel)
Main check points:
●Is the connection between control panel AP1 and compressor COMP secure? Loose? Is the connection in correct order?
●Is the voltage input of the machine within normal range? (Use AC voltmeter to measure the voltage between terminal L and N on the
wiring board XT)
●Is the compressor coil resistance normal? Is the insulation of compressor coil against the copper tube in good condition?
●Is the working load of the machine too high? Is the radiation good?
I●s the charge volume of refrigerant correct?
Fault diagnosis process:
Refer to the
Electrical Wiring
Diagram and check
if the connection
between AP1 and
COMP is loose and if
the connection order
is correct.
compressor resistance on
Installation and Maintenance
Energize and
switch on
IPM protection
occurs after the
Y
machine has run for
a period of time?
the two ends of celectrolytic
Y
Please confirm:
1. If the indoor and
outdoor heat
exchangers are
dirty? If they are
obstructed by other
objects which affect
the heat exchange
capacitor C2
of indoor and
according to Electrical
outdoor unit.
Wiring Diagram.
2. If the indoor and
outdoor fans are
working normally?
3. If the environment
temperature is too
high, resulting in
capacitor C2. Then,
that the system
use capacitance
pressure is too high
meter to measure
and exceeds the
the capacitor C2.
permissible range?
Verify as per the
Parameters Sheet.
4. If the charge
volume of
refrigerant is too
much, resulting in
that the system
pressure is too
high?
5. Other conditions
resulting in that the
system pressure
becomes too high.
If the connection
between AP1 and
COMP is unsecure
Y
or the connection
order is wrong?
Use ohmmeter to
measure the resistance
between the three
terminals on compressor
COMP, and compare the
measurements with the
Service Manual.
Use ohmmeter to
measure the resistance
between the two
terminals of compressor
COMP and copper tube.
Use AC voltmeter
If the voltage
to measure the
between terminal L
voltage between
and N on wiring
terminal L and N
board XT is within
on the wiring
210VAC~250VAC?
board XT)
Restart the unit. Before
protection occurs,
Voltage between
use DC voltmeter to
measure the voltage
capacitor is
between the two
ends of electrolytic
higher than
capacitor on control
250V
panel AP1
N
Stop the unit and
disconnect the power
supply. Then, check
The connection
the connection of
of capacitor C2
Stop the unit and
Remove the wires
disconnect the power
on the two ends of
supply. Wait 20 minutes,
or use DC voltmeter to
measure the voltage
between the two ends of
capacitor C2, until the
voltage is lower than 20V
Replace the capacitor
If capacitor
C2. Then, energize
Y
C2 is failed?
and start the unit.
Replace the
N
control panel AP1
Take corrective actions
If there is any
according to Technical
abnormality
Y
Service Manual, and
described above?
then energize and start
the unit.
N
control panel AP1
Connect the control panel
AP1 and compressor
COMP correctly according
to the Electrical Wiring
Diagram. Then, energize
and start the unit.
If the
Replace the
resistance is
compressor
N
normal?
Resistance higher
than 500M ?
Y
Replace the
control panel
AP1
END
Check the supply
voltage and
N
restore it to
210VAC~250VAC
Y
If the unit can
N
work
normally?
Reconnect the
capacitor C2 according
to Electrical Wiring
Y
Diagram. Then,
Restart the
is loose.
unit.
N
If the unit can
N
work normallv?
If the unit can
work normally?
N
If the unit can
work normally?
Replace the
N
If the unit can
work
normally?
COMP
N
Y
Y
Y
Y
Y
43
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