Service manual

[ VIII Troubleshooting ]
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HWE08010 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) Brown (F) White
(B) Red (G) Control board
(C) Blue (H) Connection (CN60)
(D) Orange (I) Drive circuit
(E) Yellow (J) Linear expansion valve
Phase
number
Output pulse
1234
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)
(B)
(C)
(C)
(D)
(D)
(E)
(E)
(F)
(F)
12VDC
M
4
6
2
3
5
1