Troubleshooting Lev, Fcv Problems - Mitsubishi Electric PURY-M200YNW-A1 Service Handbook

[8-8 Troubleshooting LEV, FCV Problems ]

8-8 Troubleshooting LEV, FCV Problems
8-8-1 General Overview on LEV Operation (Outdoor unit)
LEV operation
LEV are stepping-motor-driven valves that operate by receiving the pulse signals from the indoor and outdoor unit control
boards.
(1) Outdoor LEV (LEV2a, 2b, 2c, and 2d)
The valve opening changes according to the number of pulses.
1) Control boards and LEV (outdoor unit) (LEV2a, 2b, 2c, and 2d)
LEV
Blue
4
Red
6
M
Yellow
2
5
1
Orange
White
2) Pulse signal output and valve operation
Output
(phase)
number
1
1 ON
2 ON
3 OFF
4 OFF
24
- chapter 8
ø4
ø3
ø2
ø1
Output state
2 3 4
OFF OFF ON
ON OFF OFF
ON ON OFF
OFF ON ON
Control board
Red
Blue
Orange
Yellow
White
Output pulses change in the following orders when the
Valve is closed; 1 2
Valve is open; 4 3
*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.
DC12V
6
5
Drive circuit
ø4
4
ø3
3
ø2
2
ø1
1
3 4 1
2 1 4
BS_08_L