ORANGE
PURPLE
RED
detection resistor.
<Reference>
If power module is defected, self diagnosis lamps on the MAIN P.W.B. may indicate as shown below:
Fig. 4-5
POWER P.W.B.
MAIN P.W.B.
LD301
LD302
LD303
Fig. 4-4 Power module circuit (U
+
is OFF, V
–
is ON)
Since current flows at point B only when U
+
transistor and V
–
transistor are ON, the current waveform at
point B becomes intermittent waveform as shown in Fig.4-3. Since current at point B is approximately
proportional to the input current of the air conditioner, input current is controlled by using DC current (Id)
Table 4-1
Ip (peak current cut)
LD301
Blinks 2
times
Blinks 3
times
Blinks 4
times
LD301
LD301
Self-diagnosis
Self-diagnosis lamp
and mode
Abnormal low speed
rotation
Switching incomplete
- 55 -