Carrier 40MBDAQ - Page 32

40MBDAQ: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
32
DIAGNOSIS AND SOLUTION (CONT.)
P0 (IPM malfunction Diagnosis and Solution) and P4 (Inverter compressor drive error Diagnosis and Solution)
Description: When the voltage signal that the IPM sends to the compressor drive chip is abnormal, the display LED displays
“PC 00” and the air conditioner turns off.
Recommended parts to prepare:
• Connection wires
• IPM module board
• Outdoor fan assembly
• Compressor
• Outdoor PCB
Troubleshooting
At first test, the resistance between every two ports of U, V, W of IPM and P, N. If any result is 0 or close to 0, the IPM is defective. Otherwise, follow
this flowchart.
IPM module protection.
Yes
Is t
h
e power vo
l
ta
g
e norma
l
?
Is the power voltage normal ?
I
s
t
h
e
o
n
o
rm
al
Is the outdoor terminal voltage
normal?
Restart the unit when the power supply
returns to normal
No
Yes
No
R
ec
o
nnect
t
h
e
power w
i
res
Reconnect the
power wires.
Yes
Yes
˛
No
No
Are the power wires
connected properl
y
?
Are the power wires
connected properly?
Reconnect L and N.
?
Are L and N wired
correctly?
Is the bridge rectier
proper
l
y wire
d
?
Is the bridge rectier
properly wired?
No
No
Yes
Replace the PFC module
(if this has not been done already).
No
Is the voltage between P and N
properly wired according to
Check Procedures?
Replace the bridge rectier.
No
Is the bridge rectier
operating normally?
Are the reactor or
inductance wired well?
Reconnect the wiring.
No
Are the reactor or
indictance normal?
Yes
Replace the reactor
or inductance.
No
Is the connecting wire
between the main board and
the IPM board connected well?
Reconnect the main board
and the IPM board.
No
Is the outdoor unit
ventilation in working order?
Yes
Ensure the outdoor unit is
ventilating properly?
Check whether the refrigerant
system is in working order.
No
Is the outdoor fan
running properly?
Refer to the solution for the Fan Speed
is Out of Control malfuction.
Identify the cause and resolve.
No
Yes
No
Yes
Yes
Is the compress
running normally?
Yes
Re
p
lace the com
p
ressor
Replace the compressor.
No
Replace the IPM board.
Is the problem resolved?
Replace the outdoor main PCB.
Is the problem resolved?
No
Is the compressor’s connecting wire
well connected?
R
ec
o
nnec
t
h
e connecting
wire of the compressor
p
Reconnect he connecting
wire of the compressor
No
Yes
Yes
Is the voltage between L and N normal?
Is the bridge rectier
input voltage normal?
Reconnect the
bridge rectier.