Mitsubishi Electric MSC-A07YV-E1 Service Manual page 14

8-6. FAN MOTOR CONTROL
(1) Rotational frequency feedback control
The indoor fan motor is equipped with a rotational frequency sensor, and outputs signal to the microprocessor to
feedback the rotational frequency. Comparing the current rotational frequency with the target rotational
frequency (High,Med.,Low), the microprocessor controls SR141 and adjusts fan motor electric current to make the
current rotational frequency close to the target rotational frequency. With this control, when the fan speed is switched,
the rotational frequency changes smoothly.
(2) Fan motor lock-up protection
When the rotational frequency feedback signal is not output for 12 seconds, (or when the microprocessor cannot detect
the signal for 12 seconds) the fan motor is regarded locked-up. Then the electric current to the fan motor is shut off. 3 min-
utes later, the electric current is applied to the fan motor again. During the fan motor lock-up, the OPERATION INDICA-
TOR lamp flashes on and off to show the fan motor abnormality. (Refer to page 21.)
8-7. AUTO VANE OPERATION
(1) Vane motor drive
These models are equipped with a stepping motor for the horizontal vane. The rotating direction, speed, and angle of
the motor are controlled by pulse signals (approx. 12V) transmitted from indoor microprocessor.
(2) The horizontal vane angle and mode changes as follows by pressing the VANE CONTROL button.
(3) Positioning
The vane is once pressed to the vane stopper below to confirm the standard position and then set to the desired angle.
Confirming of standard position is performed in case of follows.
(a) When the OPERATE/STOP(ON/OFF) button is pressed.
(b) When the vane control is changed from AUTO to MANUAL.
(c) When the SWING is finished.
(d) When the test run starts.
(e) When the power supply turns ON.
(4) VANE AUTO ( ) mode
In VANE AUTO mode, the microprocessor automatically determines the vane angle to make the optimum room-temper-
ature distribution.
1 In COOL and DRY operation
2 In FAN operation
<
MU-A07/A09/A12YV,
MUX-A10/A19/A20/A22/A25/A26WV
2 In HEAT operation
<MUH-A07/A09/A12YV, MXZ-A18/A26/A32WV>
(5) Dew prevention
During COOL or DRY operation at Vane Angle 4 or 5 when the cumulative operation time of compressor exceeds 1
hour, the vane angle automatically changes to Angle 1 for dew prevention.
(6) SWING MODE (
By selecting SWING mode with the VANE CONTROL button, the horizontal vane swings vertically. The remote controller
displays " ".
High
>
)
High
Med.
Low
Vane angle is fixed to Angle 1.
Vane angle is fixed to Angle 4.
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