Carrier 42LUVH045N - Page 37

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9.2.2 E1(indoor / outdoor units communication protection) error diagnosis and solution
Disconnect the power supply, after 1
minute, connect the power supply, turn
on the unit with remote controller
Does the unit work
normally?
Check the wiring
between indoor and
outdoor unit. Is the
connection of L, N, S
and GND good?
Is the GND connection
on outdoor PCB good?
NO
NO
Reconnect and retest
again
Is the LED4(red) on
outdoor PCB bright
and LED1(yellow)
blinking?
Replace outdoor PCB.
Yes
Yes
The power supply for
outdoor PCB is fail.
Check the wiring on
outdoor PCB
comparing with wiring
plate. Is the
connection good?
No
Correct the
connection.
Yes
No
Replace indoor
PCB and
repower on. Is
the failure
cleared?
Yes