Johnson Controls YVAHP072B31S, Service Manual

Page: 1364 / 1796

3-50
Service Manual
TROUBLESHOOTING
3.2.2 Troubleshooting Using Alarm Codes
Alarm
Code
Activation of Protection Device (Float Switch) in Indoor Unit
(Except for Wall Mount Type)
O
7KH581LQGLFDWRUUHGÀDVKHV
O
The indoor unit number (refrigerant cycle number - address number), the alarm code, the model code*
1)
,
the model name*
1)
and the number of connected indoor units are displayed on the LCD. The indoor unit
number and the alarm code are displayed on the 7-segment display of the outdoor unit PCB.
*1) Except for some models.
+
This alarm code is displayed when the contact between #1 and #2 of CN14 on the I.U. PCB is opened
for over 120 seconds during the cooling, dry, fan, or heating operation.
I.U. PCB: Indoor Unit PCB
*2): Connector for Drain Pump
Indoor Unit Type
A
Connector for Drain Pump
Ducted High Static PCN6 on PCB1
Ducted Medium Static PCN6 on PCB1
Ducted Slim PCN6 on PCB1
4-Way Cassette CN36 on PCB1
1-Way Cassette CN36 on PCB1
Turn OFF power supply and remove
connectors A *
2 and CN14 on I.U. PCB.
Then turn ON power supply. Is DC12.5~
13.5V applied between A *
2 terminals?
Turn OFF power supply and connect
connector CN14 on I.U. PCB. Then
turn ON power supply. Is voltage applied
between A *
2
terminals less than 12.5V?
Failure of I.U. PCB
Failure of Condensate Pump
Activation of Float Switch FS
or Failure of Float Switch.
Yes
Make sure short circuit does not occur between A * 2 terminals
when measuring the voltage. Short circuit will lead to I.U. PCB
malfunction.
Yes
No
No
Failure of Drain Pump
Indication on Outdoor Unit PCB
Unit No.
of Malfunctioning Indoor Unit
Alarm Code