mundoclima MUCR-H6 Series, Service Manual

Page: 129 / 143

Troubleshooting
Electrical Control System 127
For 485 communication (Models 18 to 60k)
Communication malfunction between indoor
and outdoor units
Communication malfunction between indoor
and outdoor units
E2 display
E2 display
No
Power off, then restart the unit 2
minutes later
Power off, then restart the unit 2
minutes later
Adopt shield cable/Shield
cable earthing.
Adopt shield cable/Shield
cable earthing.
No
Yes
Correct the connection.
Correct the connection. No
Yes
Remove interference or
add magnet ring on power
wire
Remove interference or
add magnet ring on power
wire
Yes
Yes
Replace the signal wire.
Replace the signal wire. Yes
Pull out and insert back.
Pull out and insert back. No
No
Replace indoor main PCB, is the
error distinguished?
Replace indoor main PCB, is the
error distinguished?
Yes
Replace the outdoor Main PCB.
Replace the outdoor Main PCB.
No
Check whether
there’s any
interference.
Such as too many lamps, power
transformers? Or the signal wire
is too long?
Check whether
there’s any
interference.
Such as too many lamps, power
transformers? Or the signal wire
is too long?
Check whether the signal wire
is shield cable or whether the
shield cable is earthing?
Check whether the signal wire
is shield cable or whether the
shield cable is earthing?
Check whether the wire is
correct polarity? P to P, Q to Q,
E to E?
Check whether the wire is
correct polarity? P to P, Q to Q,
E to E?
Check whether the signal wire
is broken?
Check whether the signal wire
is broken?
Check whether the signal wires
insert on PCB well?
Check whether the signal wires
insert on PCB well?
E1