Carrier 38QUS012DS - Page 58

5
2 Indoor unit and outdoor unit communication protection error diagnosis and solution (E1)
Error Code
E1
Malfunction decision
conditions
Indoor unit does not receive the feedback from outdoor unit during 110
seconds and this condition happens four times continuously.
Supposed causes ● Wiring mistake
● Indoor or outdoor PCB faulty
Measure Vs, is it positive fluctuation?
(Vs is the voltage between S and N of
outdoor unit. Red pan-S, Black pan-
N)
Measure Vs, is it positive fluctuation?
(Vs is the voltage between S and N of
outdoor unit. Red pan-S, Black pan-N)
Yes
Power off, then restart the unit 2 minutes later
Power off, then restart the unit 2 minutes later
No
Replace the outdoor main PCB.
Power on. Is the error
extinguished?
Replace the outdoor main PCB.
Power on. Is the error
extinguished?
Check the outdoor wiring connection
Check the outdoor wiring connection
Replace the indoor main PCB.
Power on. Is the error
extinguished?
Replace the indoor main PCB.
Power on. Is the error
extinguished?
Yes
Replace the outdoor main PCB.
Replace the outdoor main PCB.
No
Replace the indoor main PCB.
Replace the indoor main PCB.
No
Check the indoor wiring connection
Check the indoor wiring connection
Yes
Yes
Check whether reactor
is normal?
Check whether reactor
is normal?
Yes
Replace the reactor
Replace the reactor
No