Hitachi RAS-2-HVNP Service Manual page 232

8. Troubleshooting
19
Alarm code
• The RUN LED flickers and "ALARM" is displayed on the remote control switch.
• The unit number, the alarm code and the unit code are alternately displayed on the set temperature section.
• The unit number and the alarm code are displayed on the display of the outdoor unit PCB1.
- This alarm code is displayed when the following conditions occurs three times in 30 minutes. Indoor fan rotates less
than 70 rpm for 5 seconds during operation.
• When the cause is checked by means of this flow chart, confirm that fan speed setting is Hi
Occurrence of
Alarm Code "19"
Check connectors PCN7
and CN1 on I.U. PCB1.
Check that 220/240V is
applied between
L1 and N of TB1.
Yes
Is LED4 on
I.U. PCB1 OFF?
(*1)
No
Is LED5 on
I.U. PCB1 OFF?
(*2)
No
Is DC power
output of I.U. PCB1
normal? (*3)
Yes
Is DC power
output of I.U. PCB1
normal? (*4)
Yes
Is fan motor
speed control command
to fan motor correctly?
(*5)
No
Faulty I.U. PCB1
Replace I.U. PCB1.
218
SMGB0079 rev.0 - 01/2013
Activation of the protection device for the indoor fan motor (RCI, RCIM)
Perform the following check after setting
the air flow volume to "HIGH".
A high voltage is applied to electrical parts.
Perform the check carefully to prevent
an electric shock.
NOTE:
Turn OFF the power source securely
before connector checking.
If not, it may cause DC fan motor failure.
(Built-in PCB for DC fan motor may be damaged.)
Yes
Faulty I.U. PCB1
Yes
Faulty I.U. PCB1
No
Faulty I.U. PCB1
No
Faulty I.U. PCB1
Yes
No
Does Fan
Motor run?
Yes
Yes
Is speed pulse
signal to I.U. PCB1
correctly? (*6)
No
Faulty Fan Motor
LED5
PCN6 PCN4
PCN7
LED5
T1
PCN1
VDC-
CN1
(*1)
The electrical source for I.U. PCB1
is not supplied when LED4
is turned OFF.
(*2)
Abnormal voltage is supplied
for fan motor.
(Normal Voltage: DC280V)
(*3)
Measure the voltage between
VCC15 and VDC (15V+10%) by tester.
(*4)
Measure following check points voltages by tester.
Between VCC05 and GND: 5V+4%
Between VCC13 and GND: 13.1V+10%
(*5) Perform the operation with disconnecting CN1 on I.U. PCB1.
It is normal if more than 1V generates between No.3 pin of CN1
and VDC- (check point) for approx. 10 seconds after starting
the operation.
(NOTES)
1. Even if the operation is stopped, 0.3 to 0.4V may generate.
2. The voltage may not generate sequentially after 10 seconds
from starting the operation to perform the operation "#".
(*5)
Faulty Fan Motor
(*6) Perform the operation with connecting CN1 on PCB1.
It is normal if several voltages generate between
No.2 pin of PC4 and VDC- (check point).
(NOTE)
Even if the operation is stopped, approx. 0.2V may generate.
(*6)
Faulty I.U. PCB1
Replace Fan Motor.
PC4
PC4-#2
RSW1 DSW6 DSW9
DSW3
EF2 CN2 5
TP
L1
L3 5
SW1
RSW2 DSW5 DSW4
+
LED4
IC1
CN28
TR1
LED6
THM1 THM2 THM3 THM4 THM5 CN33 CN9 CN10
CN1 +
HA
CN36 CN8 CN7 THU1 CN5 CN14 CN4 CN3 CN6
VCC13
VCC15 GND VCC05
Replace I.U. PCB1.
Replace I.U. PCB1.
Replace I.U. PCB1.
Replace I.U. PCB1.
Replace Fan Motor
Replace I.U. PCB1.