Inverter System Control - Mitsubishi Electric MS-A WA Service Technical Manual

<SWING operation>
In swing operation of ECONO COOL operation mode, the initial air flow direction is adjusted to "Horizontal".
According to the temperature of indoor coil thermistor RT12 at starting of this operation, next downward blow time is
decided. Then when the downward blow has been finished, next horizontal blow time is decided.
For initial 10 minutes the swing operation is performed in table G~H for quick cooling.
Also, after 10 minutes when the difference of set temperature and room temperature is more than 3.6°F (2°C), the
swing operation is performed in table D~H for more cooling.
The air conditioner repeats the swing operation in various cycle as follows.
A
B
C
D
E
F
G
H

2-7. INVERTER SYSTEM CONTROL

2-7-1. Inverter main power supply circuit
MUZ-A09/12/15/17 MUY-A15/17 MUZ-FD MUZ-FE09/12 MSZ-GE06/09/12/15/18 MUY-GE09/12/15/18
NOISE
POWER
FILTER
SUPPLY
CIRCUIT
Function of main parts
NAME
INTELLIGENT POWER MODULE
SMOOTHING CAPACITOR
CURRENT TRANSFORMER
DIODE MODULE 1
RESISTOR
RELAY
DIODE MODULE 2
BOOSTER
CHOPPER
SWITCHING POWER TRANSISTOR
CIRCUIT
REACTOR
Temperature of indoor
coil thermistor (°F/°C)
59/15 or less
59/15 to 63/17
63/17 to 64/18
64/18 to 68/20
68/20 to 70/21
70/21 to 72/22
72/22 to 75/24
more than 75/24
REACTOR
RESISTOR
RELAY
DIODE
MODULE2
BOOSTER CHOPPER CIRCUIT
It supplies 3-phase AC power to compressor.
It stabilizes the DC voltage and supplies it to INTELLIGENT POWER MOD-
ULE.
It measures the current of the compressor motor.
It converts the AC voltage to DC voltage.
It absorbs the rush current not to run into the main power supply circuit when
the electricity turns ON.
It keeps the RESISTOR, which restricts rush current, short-circuited while the
compressor is operating.
It improves power factor.
It controls the bus-bar voltage.
Downward blow time Horizontal blow time
(second)
2
5
8
11
14
17
20
23
DIODE
MODULE1
+
+
~ ~
SMOOTHING
CAPACITOR
-
+
~ ~
SWITCHING
POWER
-
TRANSISTOR
12
(second)
23
20
17
14
11
8
5
2
CURRENT
TRANSFORMER
U
U
P
V
V
N W
W
COMPRESSOR
INTELLIGENT
POWER
MODULE
FUNCTION
MS
3~