Service Manual

8. Troubleshooting
219
SMGB0079 rev.0 - 01/2013
8
Alarm code
19
Activation of the protection device for the indoor fan motor (RPK)
• The RUN LED ickers 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.
• Set air ow volume “Hi” before starting this check.
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ON
12
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+
GND1
VCC1
VCC05
PCN500
VDC
LED1
VCC15
PC4
PCN550
PC4-2
Faulty I.U. PCB
(*1)
The electrical source for I.U. PCB
is not supplied when LED4
is turned OFF.
(*2)
Abnormal voltage is supplied
for fan motor.
Is LED4 on
I.U. PCB OFF?
(*1)
Is LED1 on
I.U. PCB OFF?
(*2)
Check connectors PCN500
and PCN550 on I.U. PCB.
Yes
Replace I.U. PCB.
No
No
No
No
Faulty I.U. PCB
Replace I.U. PCB.
Is fan motor
speed control command to
fan motor sent correctly?
(*5)
Yes
Yes
Faulty I.U. PCB
Faulty I.U. PCB
Faulty I.U. PCB
Is DC power
output of I.U. PCB
normal? (*3)
Replace I.U. PCB.
Replace I.U. PCB.
Replace I.U. PCB.
(*3)
Measure the voltage between
VCC15 and VDC (15V+10%) by tester.
Yes
Yes
No
Occurrence of
Alarm Code “19”
(*4)
Measure the following voltage of each check point by a tester.
Between VCC05 and GND: 5V+4%
Between VCC13 and GND: 13.1V+10%
(Normal Voltage: DC280V)
No
Faulty Fan Motor Replace Fan Motor
Yes
Faulty I.U. PCB
Faulty Fan Motor
Is speed pulse
signal to I.U. PCB
sent correctly?
(*6)
Replace I.U. PCB.
Replace Fan Motor.
No
Does Fan
Motor run?
Yes
(*5)
(*6)
(*6) Perform the operation with PCN550 on PCB connected.
It functions normally if several voltages are generated between
No.2 pin of PC4 and VDC- (check point).
(NOTE)
Even if the operation is stopped, approx. 0.2V may be generated.
Yes
Check that 220/240V is
applied between
L1 and N of TB1.
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.)
(*5) Perform the operation with PCN550 on I.U. PCB disconnected.
It functions normally if more than 1V generates between No.4
pin of PCN550 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 be generated.
2. The voltage may not be generated sequentially after 10 seconds
from starting the operation to perform the operation “”.
Is DC power
output of I.U. PCB
normal? (*4)
 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.