Haier 2U18MS2VHB Service Manual page 109

Testing Temperature Sensors
The easiest problems to solve will involve codes that are
related to potential failure of temperature sensors. Common
problems may include loose connections, open electrically,
and out of calibration. Checking the condition of the sensors
requires a temperature probe and an ohmmeter.
The Reference Section of this manual contains temperature
resistance tables that can be used to check the calibration
of the sensors. The measured resistance must be within the
tolerances printed on the top of the tables.
To test the electrical condition of a temperature sensor
perform the following:
1. Confirm the sensor is firmly attached to the circuit board
connection plug.
2. Remove the sensor wires form the connection plug by
releasing holding tension on the plugs tension tab.
3. Use an ohmmeter to test the electrical resistance of the
sensor.
4. Measure the air temperature near the sensor and compare
the required resistance against measured resistance.
(See chart in reference section) If the sensor is within
calibration, the sensor is good. If the sensor is out of
calibration, replace the sensor. (Tube Sensors should be
removed from socket and exposed to air temperature
during test.)
2
4
Topic Title Testing
Testing Louver Motors
If the louver does not operate with command from the remote
control, either the indoor board is bad, or the louver motor
is defective. It is more likely the motor is defective than the
board. (Make sure the louver assembly is not binding and
keeping the vanes from moving.)
1. Remove power from the unit and remove the indoor unit
2. Access the circuit board.
3. Identify the inoperable louver motor on the schematic
4. Use an Ohmmeter to test the electrical continuity of the
Upper Louver
Lower Louver
5. If the motor checks out good, replace the indoor control
CONSOLE TECHNICAL OVERVIEW
cover.
drawing below and disconnect the plug from the circuit
board.
Tp Tr
CN16
BL
W
CN31
CN3
BL
W
CN16-1
W
CN22(22-1)
Main control board
B
L2 L1
W
To RJ45 DEVICE
To Outdoor Unit
DIP switches factory default setting
Note：
All Console
SW3-1 SW3-2 SW3-3 SW3-4 SW3-5 SW3-6 SW3-7 SW3-8
default 1.Dashed parts are optional.
louver motor windings. The proper resistance for each 2.Please refer to the technical service manual for detailed explanations
MODEL
SW1-1 SW1-2 SW1-3 SW1-4 SW1-5 SW1-6 SW1-7 SW1-8
of DIP switches.
3.Do not change the DIP switches setting without technical support
winding should be 292Ω from red wire (common) to any OFF
OFF OFF OFF OFF OFF USYF09UCDWA1
OFF OFF
4.Abbreviation：R-red ,B-black,BL-blue,W-white,Y/G-yellow/green,
USYF12UCDWA1
ON
OFF OFF OFF OFF OFF
OFF OFF
TEMP.-temperature, E.A.O-exrernal alarm output,Tr-indoor unit
other wire.. If the motor winding resistance is erratic or
ON OFF OFF OFF OFF USYF18UCDWA1 room temperature sensor ,Tp-indoor unit pipe temperature sensor (coil
OFF OFF OFF
temperature sensor)
shows open, the motor is defective. Replace the motor.
board.
Panel
display
W
YL
CN17
SW2
Swing motor
for lower
louver
W
Swing motor
for upper
louver
BL
CN10
W
Note:
I-7
Wired c
display(
07 flas
upper
Outdoo
+20 cor
HEX co