Testing Louver Motors; Testing Communication Circuit - Haier 2U18MS2VHB Service Manual

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
cover.
2. Access the circuit board.
3. Identify the inoperable louver motor on the schematic
drawing below and disconnect the plug from the circuit
2014.11.29
board.
FLOAT
PIPING
SWITCH
TEMP.
ROOMCARD
PANNEL
SENSOR
CN21 CN1 CN19
87654321 87654321
ON
ON
OFF OFF
BM3 BM1
CN11
CN4
CN13
REMOTE
U-HOME
CENTRAL
BM1-2 BM1-3 BTU
BM1-1
AB09SC2VHA/AB09CS2ERA
OFF OFF OFF 9000
AB12SC2VHA/AB12CS2ERA(S)
ON OFF OFF 12000
OFF ON OFF 18000 AB18SC2VHA/AB18CS2ERA(S)
ON ON OFF 24000
OFF OFF ON
28000
ON OFF ON 36000
BM1-4 BM1-5 Room card
OFF ON ON 48000 ON OFF available
ON ON ON 60000 unavailable
OFF OFF
0150515406
ROOM DC FAN
TEMP.
SENSOR
PUMP
CN9
CN3
CH1
CN6
CN8
FUSE
T5A/250VAC
CN16
CN35
N
W
B R
1 2 3
UP/DOWN
TO OUT DOOR
R:RED
NOTE1.DASHED PART ARE OPTIONAL.
B:BLACK
2. USER SHOULD NOT TO SET BM1 AND BM3
W:WHITE
BM1-7 BM1-8
BM1-6
TYPE DEFINE
Y/G:YELLOW/GREEN
OFF Default
OFF OFF
COMPACT CASSETTE TECHNICAL OVERVIEW
Testing
4. Use an Ohmmeter to test the electrical continuity of the
louver motor windings. The proper resistance for each
winding can be found in this table. If the motor winding
resistance is erratic or shows open, the motor is defective.
Replace the motor.
5. If the motor checks out good, replace the indoor control
board.

Testing Communication Circuit

If an Error E7 occurs, perform the following test to determine
if the indoor control board is functioning properly to send data
to the outdoor unit.
Perform this test with the unit powered and all wiring
connected between indoor and outdoor unit.
Make sure all wiring between the indoor and outdoor unit
are correct. There should no splices between the indoor and
outdoor unit wiring connecting terminals 1 or 3. Make sure
wiring is correct, before performing this test.
G
1. Measure the DC voltage between terminals 1 and 3 on the
Y/G
indoor terminal block.
G
2. The voltage should fluctuate between 8VDC and 23VDC.
The fluctuating signal indicates a good communication
path.
3. If the voltage does not fluctuate, and the wiring is good,
the indoor board is defective.
D-7