Hitachi RAC-25NH5, Руководство по обслуживанию

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– 77 –
+
U
U
V
W
—
U
+
V
—
V
+
W
—
W
_
+
System Power Module 2
260V-360V
R24
DC current (Id)
detection resistor
A
U coil
DC compressor
motor
V coil
W coil
B
Fig. 3-5
●
Since current flows at point only when U+ transistor is ON, the current waveform at point becomes
intermittent waveform as shown in Fig. 3-3. Since current at point is approximately proportional to the
input current of the air conditioner, input current is controlled by using DC current (Id) detection resistor.
<Reference>
If power module is detective, self diagnosis lamps on the control P.W.B. may indicate as shown below:
●
Simplified check of power module (Lighting mode when operated with compressor leads disconnected)
(1) Disconnect connector of 3-pole (WHT, YEL, RED) lead wire connecting to compressor located at the
lower part of electric parts box.
(2) Set to compressor operation state (other than FAN mode) and press Start/stop switch of remote
control.
(3) If normal operation continues for more than 1 minute (LD303 lights), power module is considered
normal.
❈
Refer to other item (troubleshooting on page 94) for independent checking of power module.
Fig. 3-4 Power module circuit (U+ is ON, V– is ON)
Self-diagnosis
Self-diagnosis lamp
and mode
lp (peak current cut)
LD301
Abnormal low speed
rotation
LD301
Switching incomplete
LD301
Blinks 2
times
Blinks 3
times
Blinks 4
times
Table 3-1
B B
B
Self diagnosis lamps
(LD303, 302, 301)
P.W.B (Main)