Mitsubishi Electronics MXZ-8B48NA Air Conditioner User Manual


 
56
<Output pulse signal and the valve operation>
(2) Linear expansion valve operation
Open
Extra ti
g
htenin
g
(
about 32
p
ulse
)
Pulse number
500 pulse
Opening a valve
all the way
Close
Valve position (capacity)
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 phase
become OFF.
• When the switch 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.
No sound is heard when the pulse number moves from B to A in
case coil is burnt out or motor is locked by open-phase.
• Sound can be detected by placing the ear against the screw driver
handle while putting the screw driver to the linear expansion valve.
LEV
M
1
6
:4
:4
:3
:2
:1
2
1
Red
Brown
Blue
Orange
Yellow
White
3
4
5
6
Connector LEV-A
LEV-B
LEV-C
LEV-D
LEV-E
DC12V
branch box 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 open/close through stepping motor after receiving the pulse signal from the branch box controller
board.
• Valve position can be changed in proportion to the number of pulse signal.
<Connection between the branch box 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
234
5678
OFF
OFF
ON
OFF
OFF
OFF
ON
ON
OFF
OFF
OFF
ON
ON
OFF
OFF
ON
(LEV) in Branch box