w w w . i n n o v a i r . c o m
DELUXE
Inverter
Service
M
anual
(5)
E4- Internal
motor
fan error of wall mounted air conditioner (DC motor)
Explanation of
error
Cause:
The internal fan of some highly energy efficient models is DC motor
using a green plug through which the main internal control panel can drive the
motor and sense the current rotational speed feedback. When the main internal
control panel cannot receive the rotational speed feedback signal of the motor,
it will indicate “DC motor error”. Disappearance of the rotational speed
feedback signal may be caused by:
1
.
The motor is stuck and cannot work
.
2
.
The speed feedback element inside
the fan is destroyed
.
3
. Problems
with the speed feedback signal receiving
circuit of the main internal control panel.
Inspection path:
Is DC motor stuck by foreign matter→motor destroyed →
Motor terminal connectors→Main internal control panel
Tools required
for inspection
Multimeter, a DC motor in normal working condition
Frequent
problematic part
Mechanical jam of internal fan, internal DC motor, main internal control panel
Inspection
procedure and
key points
1. Check whether the fan accelerates to extremely high speed before the error
occurs. If it can work for a period, the reason of mechanical jam can be excluded.
2. Plug and unplug the terminal of the DC motor again to exclude any fan error
due to connector loosening, pull the terminal slightly for inspection if
necessary.
3.
Temporarily unplug the presumed faulty motor and connect another DC motor
(do NOT remove the presumed faulty motor for the time being). Turn back on
the A/C. If the main control panel still indicates “internal fan error”, then
replace the main internal control panel, connect the original fan motor. If the
error disappears, replace the presumed faulty motor with the new DC motor.
4. Multimeter can be used to distinguish whether it is main control panel
problem or motor problem by: connect the motor with the main control panel
and pay attention to the second (yellow) and fourth (black) wire from the
outermost side among four lines of the terminal of the DC motor. After the air
conditioner powers on in the cooling mode for a while, the voltage between the
yellow and black wires should rise gradually and the motor should accelerates
slowly, if the DC motor still won’t rotate, then the DC motor is destroyed.
Special attention
Five lead wires division:
Count from the outermost side of the four wires of the
DC motor terminal, the first blue wire is the speed feedback wire with a voltage
of 0.5-5V when the fan rotates; the second yellow wire is the motor driving wire
with a voltage of 2.0-7.5V when the fan rotates; the second white wire is 15V
power cord with a voltage of 15V in normal condition; the fourth black wire is
0V DC earth wire which is the benchmark of all the voltage tests; the fifth (red)
wire is 310V wire which is strong with a voltage of 310V in normal condition,
so be careful of electric shock.
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