IVT AY-XP12FR-N Service Manual page 15

1.25. Winter cool
Cooling operation is available during the winter season by the built in
winter cool function.
Lower limit of outdoor temperature range is -10°C DB.
When the outside air temperature is low, the outdoor unit fan operates
at slower speed.
NOTE: Built-in protect device may work when outdoor temperature
falls below 21°C DB., depending on conditions.
1.26. Auto restart
When power failure occures, after power is recovered, the unit will
automatically restart in the same setting which were active before the
power failure.
1.26.1 Operating mode (Cool, Heat, Dry)
• Temperature adjustment (within 2°C range) automatic operation
• Temperature setting
2. Explanation of cluster circuit
The cluster unit generates cluster ions, which are circulated throughout the room by the air flow created by the blower fan (indoor unit fan motor) in
the air conditioner unit.
1) When microcomputer output turns "H," the IC6 output changes to "Lo," turning ON the SSR and applying 230 V to the cluster unit for the genera-
tion of cluster ions (positive and negative ions).
AC230V
Microcomputer output
3. Outline of PAM circuit
3.1. PAM (Pulse Amplitude Modulation)
The PAM circuit varies the compressor drive voltage and controls the rotation speed of the compressor.
The IGBT shown in the block diagram charges the energy (electromotive force) generated by the reactor to the electrolytic capacitor for the inverter
by turning ON and OFF.
Noise
AC
filter
230V
R75
R23
IC6
R20
Reactor L5
Reactor L6
AC clock
detection
circuit
[PAM drive circuit]
Microcomputer (IC1)
PAM drive circuit block diagram
• Fan setting
• Air flow direction
• Power ON/OFF
• Automatic operation mode setting
• Swing louvre
• Plasmacluster mode
1.26.2 Setting not memorized
• Timer setting
• Full power setting
• Internal cleaning
1.26.3 Disabling auto restart function
By removing (cutting) jumper J (JPJ) on the printed circuit board
(PCB), the auto restart function can be disabled.
12V
R76
C23
SSR
RE RH
DB1
+
DB2
IGBT
drive
circuit
IGBT
2 – 11
AYXP12FRN
Cluster unit
1
1
3 3
5
6
IPM
Compressor
Overvoltage
Compressor
detection
position
circuit
detector