[
VIII
Troubleshooting ]
- 26 -
HWE20150
GB
1) Summary of linear expansion valve (LEV) operation
The LEV is operated by a stepping motor, which operates by receiving a pulse signal from the indoor control board.
The LEV position changes in response to the pulse signal.
Indoor control board and LEV connection
Pulse signal output and valve operation
The output pulse changes in the following order:
When the valve closes 1 -> 2 -> 3 -> 4 -> 1
When the valve opens 4 -> 3 -> 2 -> 1 -> 4
When the valve position remains the same, all output signals will be OFF.
If any output signal is missing or if the signal remains ON, the motor vibrates and makes clicking noise.
(A)
Red
(G)
Control board
(C)
Blue
(H)
Connection (CN60)
(D)
Orange
(I)
Drive circuit
(E)
Yellow
(J)
Linear expansion valve
(F)
White
Phase
number
Output pulse
1
2
3
4
ø1
ON
OFF
OFF
ON
ø2
ON
ON
OFF
OFF
ø3
OFF
ON
ON
OFF
ø4
OFF
OFF
ON
ON
4
3
6
5
2
1
(G)
(H)
(I)
(J)
(A)
(A)
(B)
(C)
(C)
(D)
(D)
(E)
(E)
(F)
(F)
12VDC
M
4
6
2
3
5
1
