Fisher FSKIF-121AE2-EU Service Manual page 144

Troubleshooting
For 485 communication
E2 display
E1
Communication malfunction between indoor
and outdoor units
Power off, then restart the unit 2
minutes later
Yes
Check whether there's any
interference.
Such as too many lamps, power
transformers? Or the signal wire
is too long?
No
Check whether the signal wire
is shield cable or whether the
shield cable is earthing?
Yes
Check whether the wire is
correct polarity? P to P, Q to Q,
E to E?
Yes
Check whether the signal wire
is broken?
No
Check whether the signal wires
insert on PCB well?
Yes
Replace indoor main PCB, is the
error distinguished?
No
Replace the outdoor Main PCB.
140
Remove interference or
Yes add magnet ring on power
Adopt shield cable/Shield
No
cable earthing.
No Correct the connection.
Yes Replace the signal wire.
No Pull out and insert back.
wire
Electrical Control System