Mitsubishi MXZ-*C*NA Series Service Manual page 13

8-5. 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 have passed with the room temperature 2°F (1°C) below
the set temperature.
HEAT mode changes to COOL mode when about 15 minutes have passed with the room temperature 2°F (1°C) above
the set temperature.
NOTE 1
If two or more indoor units are operating in multi system, there might be a case that the indoor unit, which is operating in
(AUTO), 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 two 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 blinks 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 minutes) 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 flow-
ing may be heard, they are not malfunction. The reason is that the refrigerant continuously flows into it.
8-6. AUTO VANE OPERATION
1. Horizontal vane
(1) Vane motor drive
These models are equipped with a stepping motors for the horizontal vanes. 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.
(3) Positioning
To confirm the standard position, the vane move until it touches the vane stopper. Then the vane is set to the select-
ed 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.
OBH736A
OPERATION INDICATOR
AUTO 1 2
Lighted
Blinking
Not lighted
3 4 5 SWING
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