Carrier 38MGRBQ18B-3 - DIAGNOSIS AND SOLUTION (CONT); Inverter Module (IPM) Malfunction

38MGRBQ: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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DIAGNOSIS AND SOLUTION (CONT)
Inverter module (IPM) malfunction diagnosis and solution
Troubleshooting
ERROR CODE
P6 / PC 00
MALFUNCTION DECISION
CONDITIONS
When the voltage signal, that the IPM sends to the compressor drive chip is abnormal, the display LED displays
P6 or PC 00 and the unit turns off.
SUPPOSED CAUSES
Wiring mistake
IPM malfunction
Faulty outdoor fan assembly
Compressor malfunction
Faulty outdoor PCB
IPM module protection
Check whether the voltage range
of P-N on IPM module is normal:
DC277-356V for 18-27KBtu/h;
DC277-410V for 36K-48KBtu/h
Yes
Yes
No
Yes
Check whether the input
power supply is correct.
208-230V, 1N, 60Hz
No
No
Regulate it to correct, then
check whether the system
is working normally.
Check whether the
power supply line is
connected correctly.
Yes
Connect it tight.
No
Check whether the connecting
line between the mainboard and
the IPM module is well
connected.
Yes
Connect it tight
No
No
No
Connect it well, check
ok or not?
Check whether the connecting
compressor line is connected
correctly.
Replace the IPM module,
Check whether the system is
working normally.
No
No
Replace the main board.
Check whether the system can work
as designed.
No
Replace the compressor. Check
whether the system can work as
designed.
Check whether the lines
in E-part box are
connected tight.
Yes
Connect it tight.
No
No
Yes
No
Replace the bridge rectifiers
Check whether the bridge rectifiers are
normal.
Use the multimeter to measure
the resistance between the two
terminals. Check whether there is a
condition that resistance value is 0.
Check whether the connecting line of
every reactor is normal. If the line is
broken, the resistance of the two ports is
ь˗Check whether the PFC module
broken .
Replace the connecting line or
reactor or replace the PFC module.
Yes
No
No
Yes
Issue is resolved.
Check if the outdoor fan
runs properly or the outdoor
unit ventilation is good.
No
For AC fan models, please refer
to 9.4 Trouble Criterion Of Main
Parts, check whether the
resistance of the fan motor is
normal. If not, replace the fan
motor.
For DC fan models, refer to
the solution of fan speed has
been out of control malfunction
. Find out the cause and have it
solved.
Yes
Yes
Yes