Mitsubishi Electric LGH-50RSDC-E1 Handbook page 18

LED 1 LED 11 LED 2 LED 3
(red) (green) (red) (green)
2 5
- -
blinks blinks
6 or
2
- 7 -
blinks
blinks
6 or
2
- - 7
blinks
blinks
9 9 9 9
blinks blinks blinks blinks
3
- - -
blinks
1 Each LED does not blink simultaneously in some cases.
In case multiple errors have occurred at the same time, each LED will blink simultaneously.
When reconnecting the power supply, wait more than 5 minutes after power-off, and then turn it on again.
Symptom
EA fan opera- The EA fan does not
tion failure rotate properly.
EA fan motor wire
connection error
EA fan motor mal-
function
EA fan motor sensor
malfunction
Large circuit board
malfunction
SA fan motor Wire connection error
sensor failure of SA fan motor sensor
SA fan motor sensor
malfunction
Large circuit board
malfunction
EA fan motor Wire connection error
sensor failure of EA fan motor sensor
EA fan motor sensor
malfunction
Large circuit board
malfunction
Communication Connection error
failure between between the circuit
the circuit boards
boards 1
The external signal
wires and power sup-
ply cable are too close.
Connection error of
transformer
Transformer malfunc-
tion
Connection error of
reactor
Reactor malfunction
Circuit boards mal-
function
Damper failure Damper operation
error
Wire connection error
of the damper unit
Connection error
between the circuit
boards
Cause
Check whether the fan turns by hand.
Check the wiring of the connector (CN7) on
the circuit board and the fan motor.
Check the coil resistance of the fan motor.
If it has a defect, replace the fan motor.
Check the signal voltage of the fan motor sen-
sor. If it has a defect, replace the fan motor.
Replace the circuit board if none of above
related actions works.
Check the wiring of the connector (CN8) on
the circuit board and the fan motor sensor.
Check the signal voltage of the fan motor sen-
sor. If it has a defect, replace the fan motor.
Replace the circuit board if none of above
related actions works.
Check the wiring of the connector (CN9) on
the circuit board and the fan motor sensor.
Check the signal voltage of the fan motor sen-
sor. If it has a defect, replace the fan motor.
Replace the circuit board if none of above
related actions works.
Check the connections of the connectors
(CN10, CN15) on the circuit boards.
Keep the wires for fan speed and bypass
condition selections more than 10 cm away
from the power supply cable.
Check the connection of the connectors
(CN2, CN14) on the circuit boards.
Check the output of the transformer. If it has
a defect, replace the transformer.
Check the connection of the connectors
(CN4, CN5) on the circuit board.
Check the resistance of the reactor. If it is
open, replace the reactor.
Replace both circuit boards if none of above
related actions works.
Remove the rod, and then check whether
the damper plate moves by hand.
For removing the rod, open the maintenance
cover and remove the guards from the unit.
Check the wiring of the connectors (CN3,
CN17) on the circuit boards and the damper
unit.
Check the connection of the connectors
(CN10, CN15) on the circuit boards.
─ 18 ─
Corrective action