Johnson Controls YVAHP072B31S, Service Manual

Page: 1366 / 1796

3-52
Service Manual
TROUBLESHOOTING
Alarm
Code
Activation of Protection Device (Float Switch)
in Wall Mount Type Indoor Unit
*1): Refer to Section 3.1.4 (3).
Is DC12V applied between #2 of CN14
and GND?
Activation of Float Switch (FS)
or Incorrect Wiring
Failure of I.U. PCB
Yes
No
Cause Check Item
Action
(Turn OFF Main Switch)
Event
Activation of
Float Switch
(when drain-up
mechanism is
installed)
Check continuity when
drain level is low.
Check drain pan.
Check drainage by
pouring water.
High Drain
Level
Failure of
Float Switch
Clogging of
Drainage
Upward Slope
Drain Piping
Remove
foreign particles.
Replace float switch
if faulty.
Failure
Measure resistance
with tester. Replace and
tighten connector. Contact
Failure
Check connection. Repair connection.
Connection
Failure
Check PCB in
Self-Checking Mode *1).
Replace it if faulty. Failure of Indoor Unit PCB
Connect them correctly. Failure of Wiring
Check whether
short-circuited connector
is connected to CN14.
Indication on Outdoor Unit PCB
Unit No. of
Malfunctioning Indoor Unit
Alarm Code
THM1 THM2 THM3 THM4 THM5 CN19 CN25
CN1 CN3 CN4
CN9
CN12
CN13
CN10
GND
CN14 HA
TP RSW
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.