Mitsubishi Electric LGH-F300RVX-E Handbook page 19

No. Problem
7 The damper does
not operate even
though the trial
operation switch
(SW2-1) on the cir-
cuit board is turned
ON.
8 Abnormal noise
comes from the
damper motor
9 Even though the
remote controller is
operated to change
the ventilation
mode, the venti-
lation mode is not
changed.
Factor
The connector between the
damper motor and circuit
board is disconnected.
Mechanical failure
Damper motor failure
Circuit board failure
Mis-assembling of the damp-
er motor
Damper motor failure
The outdoor temperature is
46.4°F (8°C) or lower.
The signal is input to the
Bypass mode switching input
(CN26 [1] [2]).
The Lossnay unit is perform-
ing the Night-purge opera-
tion.
The pre-heater is ON, or
within one hour after the
pre-heater is turned OFF.
Check the connection of the connector (CN7) on the
power circuit board.
Remove the rod of the damper board and check if the
damper board can be moved by hand.
Remove the rod of the damper board and turn the
trial operation switch (SW2-1) ON.
The damper motor operates in about 30 seconds.
If the damper motor does not operate, replace the
damper motor (GM assembly).
Disconnect the connector (CN7) from the power cir-
cuit board and check the voltage value between the
pins of CN7 when the trial operation switch (SW2-1)
is turned ON.
(Voltage is output in about 30 seconds after switch
ON.)
If there is no voltage value, replace the circuit board.
If the problem persists, replace the damper motor
(GM assembly).
Remove the GM assembly from the main unit, and
then remove the damper motor from the damper mo-
tor casing to check the pulley position. If the position
is incorrect, adjust it as shown in the picture below,
and then reassemble the GM assembly.
Damper motor
If no error is found around the pulley and wire, re-
place the GM assembly.
When the outdoor temperature is 46.4°F (8°C) or
lower, the ventilation mode is fixed to the Energy
recovery mode.
Check the Bypass mode switching input (CN26 [1] [2]).
(See the Lossnay technical manual.)
When PZ-61DR-E is used, The ventilation mode
cannot be changed during the Night-purge operation.
(See the Lossnay technical manual.)
When the pre-heater is ON, or for one hour after the
pre-heater is turned OFF, the ventilation mode is
fixed to the Energy recovery mode.
─ 19 ─
Corrective action
Pulley