Mitsubishi Electric CITY MULTI PEFY Series Technical & Service Manual page 21

[ VII Troubleshooting ]
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
(C)
4
(A)
M
6
(E)
2
5
1
3
(D)
(F) (B)
(A) Red
(C) Blue
(D) Orange
(E) Yellow
(F) White
Pulse signal output and valve operation
Phase
number
1
1 ON
Ø
2 ON
Ø
3 OFF
Ø
4 OFF
Ø
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.
HWE1706A
(J)
Ø4
Ø3
Ø2
Ø1
(G) Control board
(H) Connection (CN60)
( I ) Drive circuit
(J) Linear expansion valve
Output pulse
2 3
OFF OFF
ON OFF
ON ON
OFF ON
(A)
(C)
(D)
(E)
(F)
(H)
4
ON
OFF
OFF
ON
- 16 -
(G)
12VDC
6
5
(I)
Ø4
4
Ø3
3
Ø2
2
Ø1
1
GB