MITSUBISHI ELECTRIC MSH-07NV - Manual (Page 40)

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SLEEP
8-6. AUTO VANE OPERATION
(1) Vane motor drive
MSH-N series is equipped with a stepping motor for the vane. The rotating direction, speed, and angle of the motor are
controlled by pulse signals (approx. 12V) transmitted from indoor microprocessor.
(2) The auto vane angle changes as follows by pressing the VANE CONTROL ( ) button.
8-5. 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 (Hi,Me,Lo,SLEEP),
the microprocessor controls SR11 (MSH-07/09/12), IC141 (MSH-18/24) 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 has 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 INDICATOR
lamp flashes on and off to show the fan motor abnormality. (See page 49.)
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