52
➂
Trouble shooting
Problem
Check point
Corrective measure
Remove the connector from the controller board and connect diagnostic
LEDs.
Pulse signal will be sent out for 10 seconds as soon as the main switch is
turn on. If there is LED with lights on or lights off, it means the operation
circuit is abnormal.
Motor will idle and make ticking noise when motor is operated while the linear
expansion valve is locked.
This ticking sound is the sign of the abnormality.
Measure the resistance between the each coil (red-white, red-orange,
brown-yellow, brown-blue) using a tester. It is normal if the resistance
is in the range of 150
'
±
10%.
1
Check improperly connected connector terminals and the wire colors.
2
Remove the connector on the controller board side and check electrical
conductance
Operation circuit
failure of the micro
processor.
Exchange the linear
expansion valve.
Exchange the indoor
controller board at drive
circuit failure.
Exchange the linear
expansion vale.
Disconnect the connector
at the controller board,
then check the continuity.
Wrong connection of
the connector or
contact failure.
Short or breakage of
the motor coil of the
linear expansion valve.
Linear expansion
valve mechanism is
locked.
6
5
4
3
2
1
1k
"
LED
Output
(Phase)
Output
{
1
1
ON
{
2
ON
{
3
OFF
{
4
OFF
2
OFF
ON
ON
OFF
3
OFF
OFF
ON
ON
4
ON
OFF
OFF
ON
<Output pulse signal and the valve operation>
➁
Linear expansion valve operation
D
A
E
B
C
Open
Extra tightning (32 pulse)
Pulse number
2000 pulse
Opening a valve
all the way
Close
V
alve position (capacity)
Closing a valve : 1
→
2
→
3
→
4
→
1
Opening a valve : 4
→
3
→
2
→
1
→
4
The output pulse shifts in above order.
❈
1. When linear expansion valve operation stops, all output phase
become OFF.
2. At phase interruption or when phase does not shift in order,
motor does not rotate smoothly and motor will locks and vibrates.
❈
When the switch is turned on, 2200 pulse closing valve signal
will be send till it goes to
A
point in order to define the valve posi-
tion.
When the valve move smoothly, there is no noise or vibration
occurring from the linear expansion valve : however, when the
pulse number moves from
E
to
A
or when the valve is locked,
more noise can be heard than normal situation.
❈
Noise can be detected by placing the ear against the screw dri-
ver handle while putting the screw driver to the linear expansion
valve.
OC336--2.qxp 05.8.29 7:19 PM Page 52
