Carrier 38MBRQ36A-3 - J8 Malfunction; AC power input voltage protection

38MBR: Service Manual
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
42
J8 Malfunction
Troubleshooting
Error Code J8
Malfunction decision conditions An abnormal voltage rise or drop is detected by checking the specified voltage detection circuit.
Supposed Causes
• Faulty or wrong power supply
• Faulty wiring
• Faulty bridge rectifier
• Faulty IPM board
J8 displayed
AC power input voltage protecƟon
Check whether the
power voltage is
normal.
Restart the unit when the
power supply is normal.
No
Ensure L and N wiring is
correct.
Measure whether
the outdoor terminal
voltage is normal.
Verify the wires are well
connected.
No
Reconnect
well.
Measure whether
the voltage between L
and N is normal.
Yes
Yes
Reconnect
well.
No
Is the bridge recƟĮer’s
input voltage normal?
Yes
No
Ensure the bridge recƟĮer
wiring is correct.
Reconnect
well.
Yes
Measure is the voltage
between P and N is
normal.
***Refer to Appendix 3
No
Check whether
the bridge recƟĮer is
normal.
No
Replace
the bridge
recƟĮer.
Replace the PFC module (if available)
Yes
Check the reactor
or inductance wiring
.
No
No
Reconnect
the wiring.
Ensure the
reactor or inductance
is normal.
Yes
Replace the
reactor or
inductance.
No
Replace the IPB board.
If the IPM and main
boards are in a board,
replace the outdoor
main board.
Yes
Yes