North American HVAC MOC-12HFN1-MS0W, Service Manual

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Troubleshooting
136 Electrical Control System
2.4.4.7. E5 malfunction
Check whether the power
voltage is normal.
Measure whether outdoor
terminal voltage is normal
？
Restart the unit when the power
supply gets normal
No
Yes
No
Reconnect it well
Yes
Yes
No
Replace the IPM board, If the IPM board
and main board is in a board, replace the
outdoor main PCB
Yes
Replace the PFC module(If has)
No
Yes
Measure whether the voltage
between L and N is normal
？
Yes
Measure whether input voltage
of bridge rectifier is normal
refer to the Appendix 3
？
Yes
No
No
Measure whether the voltage
between P and N is normal
？
Replace the bridge
rectifier
No
Check whether
bridge rectifier is
normal
Check the wiring of
reactor or inductance
Reconnect the
wiring
No
Check whether reactor
or inductance is normal
Yes
Replace reactor or
inductance
No
Check the wiring of
power wires well or
correctly
Reconnect it well
Check the wiring of
L and N well or
correctly
Reconnect it well
Check the wiring of
bridge rectifier well
or correctly