Fujitsu AOU18RLB, Service Instructions Manual

Page: 33 / 71

Trouble shooting 6
INDOOR UNIT Error Method:
Detective Actuators:
Detective details:
Forecast of Cause :
62.9 103.3 134.2 176.0 233.2 312.3 Resistance Value (k )
Temperature (°F)
OK OK
OK
17.1 25.6 39.6 Resistance Value (k )
Temperature (°F)
Indoor Heat Ex.(Pipe)
Thermistor Error
Indoor unit Controller PCB
Heat Ex. temperature thermistor
When Heat Ex. Temperature Thermistor open or short-circuit is detected.
1. Connector connection failure 2.Thermistor failure 3. Controller PCB failure
Check Point 1 : Check connection of Connector
Check if connector is removed.
Check erroneous connection.
Check if thermistor cable is open.
>>Upon correcting the removed connector or miss-wiring, reset the power.
Check Point 2 : Remove connector and check Thermistor resistance value
Thermistor Characteristics (Approx. value)
If Thermistor is either open or shorted, replace it and reset the power.
Check Point 3 : Check voltage of Controller PCB (DC5.0V)
Make sure circuit diagram of indoor unit and check terminal voltage at Thermistor (DC5.0V)
If the voltage does not appear, replace Controller PCB.
68°F 50°F 41°F 32°F 23°F 14°F
122°F
11.6
140°F
10.4
149°F 104°F 86°F
Indicate or Display:
THERMISTOR
(ROOM TEMP.)
THERMISTOR
(PIPE TEMP.)
BLACK
CN3
1
2
1
2
1
2
1
2
BLACK
BLACK
BLACK
02-09
Outdoor Unit : No indication
Indoor Unit : Operation lamp: 4 time Flash, Timer lamp: 2 time Flash
Economy lamp: Continuous flash.
ERROR CODE : [E : 42]
WHITE
RED
1
2
3
1
2
3
CN1