Mitsubishi Electric NTXMMX A AA Series Service Manual page 25

3. Table of indoor unit failure mode recall function
NOTE: Blinking patterns of this mode differs from the ones of Troubleshooting check table (9-4.).
Left lamp of Right lamp of
OPERATION OPERATION
INDICATOR lamp INDICATOR lamp
Not lit Not lit
1-time blink
Not lit
every 0.5-second
2-time blink
Not lit
2.5-second OFF
3-time blink
Not lit
2.5-second OFF
5-time blink
Not lit
2.5-second OFF
11-time blink
Not lit
2.5-second OFF
12-time blink
Not lit
2.5-second OFF
13-time blink
Not lit
2.5-second OFF
OBHT802B
Abnormal point
(Failure mode)
Normal
When the room temperature thermistor
Room temperature ther-
short or open circuit is detected every
mistor
8 seconds during operation.
Indoor coil thermistor
When the indoor coil thermistor short
(Main 1, 2 and sub)
or open circuit is detected every 8
[Main 2: NTXUKS18A112AA/
seconds during operation.
NTXUKS18A112BA]
When the serial signal from the out-
Serial signal error door unit is not received for a maxi-
mum of 6 minutes.
• Float sensor is open.
Drain pump
• Float sensor detects abnormal water
Float sensor
level.
When the rotational frequency feed-
Indoor fan motor back signal is not emitted during 12
seconds the indoor fan operation.
When it cannot properly read data in
Indoor control system the nonvolatile memory of the indoor
electronic control P.C. board.
Indoor coil thermistor
When the indoor coil thermistor short
(Main 3)
or open circuit is detected every 8
[NTXUKS18A112AA/
seconds during operation.
NTXUKS18A112BA]
Condition
—
25
Remedy
—
Refer to the characteristics of the room
temperature thermistor (9-7.).
Refer to the characteristic of the main
1,2 indoor coil thermistor and the sub
indoor coil thermistor (9-7.).
Refer to 9-6. "How to check miswir-
ing and serial signal error".
• Check the float sensor and the drain
pump.
• Check the connectors of float sensor
and the drain pump.
• Refer to 9-6. "Check of float sen-
sor".
Refer to 9-6. "Check of indoor fan
motor".
Replace the indoor electronic control
P.C. board.
Refer to the characteristic of the main
3 indoor coil thermistor (9-7.).