E4 -Internal Fan Error Of Wall Mounted Air Conditioner - Toyotomi KURO Mini Service Manual

（4）E4 -Internal fan error of wall mounted air conditioner（PG motor）
Cause: PG motor is equipped with speed feedback signal line. When
the feedback signal of speed is not received by the main internal
control panel, it has no way to recognize the rotating speed of motor,
which will be indicated as "Internal fan error". Main causes for the
Explanation of
disappearance of speed feedback signal are as follows:
error
The fan is stucked; 2. The speed feedback component in the fan is
broken; 3. Error of receiving circuit for the speed feedback signal from
the main internal control panel.
Tools required
Multimeter, A PG motor in normal working condition
for inspection
Inspection path：Is PG motor stucked→Speed feedback line→Speed
feedback terminal connector→main internal control panel.
Frequent Mechanical jam problem of internal fan, PG motor, main internal
problematic part control panel
1. Check whether the fan can work for a period of time before the error
occurs. If yes, the reason of mechanical jam can be exclude.
2. Disconnect the power supply and move the fan blade of internal
machine by hand to see if there's any resistance. Some occasional
internal fan error may relate to bearing coordination.
Inspection
3. Reconnect the drive wire and speed feedback wire, thus to exclude
procedure and
any fan error due to connector loosening.
key points
4. Check whether the plug-in terminal of speed feedback on the control
panel is loose, and pull the terminal slightly for inspection if necessary.
5. Replace the motor in the faulted air conditioner with other PG motor
(do not fix it with the fan for the time being), if the main control panel
still indicates "internal fan error", then replace the main internal
control panel; if the error disappears, replace the internal fan.
error" when the internal fan is still rotating; sometimes such error will
not be reported when obvious fan problems exist (such as the
low-speed rotation due to damaged fan capacitors, or non-uniform
Special attention
rotating speed due to abnormal speed feedback.
troubleshooting of fan error. You shall compare it with the normal
condition, and detect and solve the problem in a flexible way.
The main internal control panel will not indicates "internal fan
Therefore, patience of the maintenance staff is required for the
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