Carrier 42QFD048D8S Service Manual page 113

TS30: PFC module protection diagnosis and solution
Description: When the voltage signal that IPM send to compressor drive chip is abnormal, the LED displays the failure
code and the AC turns off.
Recommended parts to prepare:
• Connection wires
• Inductance
• Outdoor main PCB
• PFC module
Troubleshooting and repair:
At first test the resistance between every two ports of U, V, W of IPM and P, N. If any result of them is 0 or close to 0, the
IPM is defective. Otherwise, please follow the procedure below:
Check whether the
Check whether the
connecting line between
connecting line between
main board and the PFC
main board and the PFC
module is connected tightly
module is connected tightly
Measure whether the voltage
Measure whether the voltage
between P and N is normal
between P and N is normal
refer to the Index？
refer to the Index？
Check whether the
Check whether the
inductance of PFC module is
inductance of PFC module is
good? If the inductance is
good? If the inductance is
good, the resistance of the
good, the resistance of the
two ports is 0
two ports is 0
Replace the PFC module
Replace the PFC module
Yes
No
Yes

Connect it tightly, check
Connect it tightly, check
No
normal or not
normal or not
No
Yes Replace the outdoor main board
Replace the outdoor main board
No Replace the inductance
Replace the inductance
Troubleshooting
Yes
Trouble is solved
Trouble is solved
