Mitsubishi Electric PUY-A12NKA7, Service Manual

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59
<Output pulse signal and the valve operation>
(2) Linear expansion valve operation
Open
Extra tightening (about 32 pulse)
Pulse number
500 pulse
Opening a valve
all the way
Close
Valve position (capacity)
A
B
C
Opening a valve : 8 → 7 → 6 →5 → 4 → 3 → 2 → 1 → 8
Closing a valve : 1 → 2 → 3 → 4 → 5 → 6 → 7 → 8 → 1
The output pulse shifts in above order.
• When linear expansion valve operation stops, all output phases
become OFF.
• When the power is turned on, 700 pulse closing valve signal will
be sent till it goes to
A
point in order to define the valve position.
(The pulse signal is being sent for about 20 seconds.)
When the valve moves smoothly, there is no sound or vibration
occurring from the linear expansion valve; however, when the
pulse number moves from
B
to
A
or when the valve is locked,
sound can be heard than normal situation.
No sound is heard when the pulse number moves from
B
to
A
in
case coil is burn out or motor is locked by open-phase.
• Sound can be detected by placing the ear against the screw driv-
er handle while putting the screw driver to the linear expansion
valve.
LEV
M
1
6
[
4
[
4
[
3
[
2
[
1
1 Red
Blue
Orange
Yellow
White
2
3
4
5
Connector LEV-A
LEV-B
12 V DC
Outdoor controller board
Drive circuit
[
3
[
2
[
1
3
2
5
4
Linear expansion valve
(1) Operation summary of the linear expansion valve
• Linear expansion valve opens/closes through stepping motor after receiving the pulse signal from the outdoor controller board.
• Valve position can be changed in proportion to the number of pulse signal.
<Connection between the outdoor controller board and the linear expansion valve>
1
ON
OFF
OFF
OFF
ON
ON
OFF
OFF
OFF
ON
OFF
OFF
OFF
ON
ON
OFF
[
1
Output
(Phase)
Output
[
2
[
3
[
4
2 3 4
5 6 7 8
OFF
OFF
ON
OFF
OFF
OFF
ON
ON
OFF
OFF
OFF
ON
ON
OFF
OFF
ON
(A12, 18, 24, 30)
OCH636A