Mitsubishi Electric PUHY-M200YNW-A1 Service Handbook page 281

[8-8 Troubleshooting LEV, FCV Problems ]
(2) Outdoor LEV (LEV1, LEV4, and LEV9)
The valve opening changes according to the number of pulses.
1) Connections between the outdoor control board and LEV1 (outdoor expansion valve)
LEV
4
6
M
2
5
1
3
2) Pulse signal output and valve operation
Output
(phase)
number 1 2
1 ON OFF OFF OFF OFF OFF ON ON
2 ON ON ON OFF OFF OFF OFF OFF
3 OFF OFF ON ON ON OFF OFF OFF
4 OFF OFF OFF OFF ON ON ON OFF
3) LEV valve closing and opening operation
Valve closed
Valve open
A
26
- chapter 8
6
5
4
3
2
1
Output state
3 4 5 6 7 8
*Upon power on, the indoor unit circuit board sends a 520 pulse
B
signal to the indoor unit LEV to determine the valve position and
always brings the valve to the position as indicated by " A " in the diagram.
(Pulse signal is output for approximately 17 seconds.)
When the valve operates smoothly, there is no sound from the LEV and no
vibration occurs, but when the valve is locked, noise is generated.
*Whether a sound is generated or not can be determined by
holding a screwdriver against it, then placing your ear against the handle.
*If liquid refrigerant flows inside the LEV, the sound may become smaller.
Fully open: 480 pulses
Pulses
Red
Brown
Blue
Orange
Yellow
White
Output pulses change in the following orders when the
Valve is open; 1 2
Valve is closed; 8 7
*1. When the LEV opening angle does not change,
all the output phases will be off.
*2. When the output is open phase or remains ON,
the motor cannot run smoothly, and rattles and vibrates.
Outdoor control board
DC 12V
6
5
Drive circuit
4 4
3 3
2 2
1 1
3 4 5 6 7 8
6 5 4 3 2 1
1
8
BS_08_E