Service manual

16
6-4-2. Linear Expansion Valve
Linear expansion valve
11
Operation summary of the linear expansion valve.
• Linear expansion valve open/close through stepping motor after receiving the pulse signal from the indoor controller board.
• Valve position can be changed in proportion to the number of pulse signal.
<Connection between the indoor controller board and the linear expansion valve.>
M
LEV
Blue
{4
{3
{2
{1
{4
{3
{2
{1
6
5
4
3
2
1
BRN
RED
BLU
ORN
YLW
WHT
Brown
Yellow
Red
White Orange
1
5
2
3
6
4
Controller board
DC12V
Drive circuit
Connector (CN60)
22
Output pulse signal and valve action
Output(phase)
{1
{2
{3
{4
ON
ON
OFF
OFF
OFF
ON
ON
OFF
OFF
OFF
ON
ON
ON
OFF
OFF
ON
Output
A
E
D
C
B
Closing
Opening
Completely sealed (80-100 pulses)
Number of pulses
Valve fully open
at 2,000 pulses
Valve position (volume)
Valve closing:1➔2➔3➔4➔1
Valve opening:4➔3➔2➔1➔4
The address of the pulse output is shifted using the procedures
mentioned earlier.
w1. All output phase will turn OFF when the LEV stops
operating.
2. When the output phase is terminated or when the phase
shift is not according to frequency, the motor rotation will
become irregular, causing the motor to vibrate or lockup.
w When the power supply is on, the closing signal of 2,200
pulse will be transmitted to decide the position of the valve.
The valve position can be determined when point A is
reached.
The LEV will not vibrate or make noise when the valve is
operating smoothly. However, when the number of pulses
change from E to A ,or if the valve lockup, there may be
more noise than under normal circumstances.
• The noise can be heard by resting your ear on the handle
of a screwdriver that is pressed against the top of the
LEV valve.
(a) LEV action
1
23
4
Note : Since the number of the connector at the controller board side and the relay connector are different, follow the color of
the lead wire.
Parts name
Linear expansion valve
Disconnect the connector then measure the resistance valve using a tester.
Refer to the next page for a detail.
Check points
Normal
150k" i10%
Abnormal
Open or short
(1)-(5)
White-Red
(2)-(6)
Yellow-Brown
(3)-(5)
Orange-Red
(4)-(6)
Blue-Brown
Blue
1
2
4
1
5
3
2
6
4
3
5
6
Brown
Yellow
Orange
Red
White
M
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