
10 Troubleshooting
Troubleshooting procedure
SMGB0091 rev.2 - 11/2015
225
10
Alarm code
19
Activation of the protection device for the indoor fan motor (RPK)
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 flow volume “Hi” before starting this check.
!
C A U T I O N
•
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.
(*1)
The electrical source for IU PCB is not supplied
when LED4 is turned OFF
Is LED4 on IU PCB
OFF? (*1)
Faulty IU PCB
Check that 230V is
applied between L1
and N of TB1
Yes
Is LED1 on IU PCB
OFF? (*2)
No
Is DC power
output of IU PCB
normal? (*3)
No
Is DC power
output of IU PCB
normal? (*4)
Yes
Is fan motor speed
control
command to fan
motor correctly?
(*5)
Yes
No
Replace IU PCB
Yes
Faulty IU PCB
Yes
Faulty IU PCB
No
Faulty IU PCB
No
Faulty IU PCB
Replace IU PCB
Replace IU PCB
Replace IU PCB
Replace IU PCB
(*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 PCN550 on IU PCB disconnected. It functions
normally if if more than 1V generates between number 4 pin of PCN550 and
VDC- (check point) for approx 10 seconds after starting the operation.
?
N O T E
• Even if the operation is stopped, 0.3 to 0.4V may generate.
•
Since the control specified in “*” is performed after the 10th second from the
start of operation, it may not be possible to obtain a steady voltage after the
10th second.
Replace IU PCB
Replace fan motor
Yes
Does fan motor
run?
No
Is speed pulse
signal to IU PCB
sent correctly? (*6)
Replace fan motor
Faulty IU PCB
(*6)
Perform the operation with PCN550 on PCB connected. It functions
normally if several voltages are generated between number 2 pin of PC4
and VDC- (chek point).
?
N O T E
Even if the operation is stopped, approx 0.2V may generate.
No
Yes
Faulty fan motor
Faulty fan motor
(*5)
(*6)
?
N O T E
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.)
Occurrence of Alarm
code “19”
Check connectors
PCN500 and PCN550
on IU PCB
Yes
+
+
+
+
++
+
+
+
+
+
+
ON
12
+
+
+
GND1
VCC1
VCC05
PCN500
VDC
LED1
VCC15
PC4
PCN550
PC4-2