Mitsubishi Electric MSZ-SF15VA-E1 Service Manual page 13

9-5. AUTO CHANGE OVER ∙∙∙ AUTO MODE OPERATION
Once desired temperature is set, unit operation is switched automatically between COOL and HEAT operation.
Mode selection
(1) Initial mode
When unit starts the operation with AUTO operation from OFF:
• If the room temperature is higher than the set temperature, operation starts in COOL mode.
• If the room temperature is equal to or lower than the set temperature, operation starts in HEAT mode.
(2) Mode change
COOL mode changes to HEAT mode when about 15 minutes has passed with the room temperature 1°C below the set
temperature.
HEAT mode changes to COOL mode when about 15 minutes has passed with the room temperature 1°C above the set
temperature.
NOTE 1
If 2 or more indoor units are operating in multi system, there might be a case that the indoor unit, which is operating in
cannot change over to the other operating mode (COOL ↔ HEAT) and becomes a state of standby.
Refer to NOTE 2 "FOR MULTI SYSTEM AIR CONDITIONER".
NOTE 2
FOR MULTI SYSTEM AIR CONDITIONER OUTDOOR UNIT: MXZ series
Multi system air conditioner can connect 2 or more indoor units with one outdoor unit.
• When you try to operate 2 or more indoor units with one outdoor unit simultaneously, one for the cooling and the others for
heating, the operation mode of the indoor unit that operates first is selected. Other indoor units cannot operate, and operation
indicator lamp flashes as shown in the figure below. In this case, please set all the indoor units to the same operation mode.
• When indoor unit starts the operation while the defrosting of outdoor unit is being done, it takes a few minutes (max. 10 min-
utes) to blow out the warm air.
• In the heating operation, though indoor unit that does not operate may get warm or the sound of refrigerant flowing may be
heard, they are not malfunction. The reason is that the refrigerant continuously flows into it.
9-6. AUTO VANE OPERATION
1. Horizontal vane
(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 (approximately 12 V) transmitted from indoor microprocessor.
(2) The horizontal vane angle and mode change as follows by pressing VANE CONTROL button.
AUTO
(3) Positioning
To confirm the standard position, the vane moves until it touches the vane stopper. Then the vane is set to the
selected angle.
Confirming of standard position is performed in the following cases:
(a) When the operation starts or finishes (including timer operation).
(b) When the test run starts.
(c) When standby mode (only during multi system operation) starts or finishes.
(4) VANE AUTO ( ) mode
In VANE AUTO mode, the microprocessor automatically determines the vane angle to make the optimum room tem-
perature distribution.
In COOL and DRY operation
Vane angle is fixed to Horizontal position.
Horizontal
position
OBH555D
OPERATION INDICATOR
1 2 3
Lighted
Blinking
Not lighted
4 5 SWING
In HEAT operation
Vane angle is fixed to Angle 4.
4
13
(AUTO),