Mitsubishi Electric CITY MULTI PUHY-400YMF-C Service Handbook page 132

Outdoor LEV
The valve percentage opening changes in proportion to the number of pulses.
(Connections between the outdoor unit's MAIN board and SLEV, (LEV1, LEV2))
1 SLEV, LEV1
Pulse Signal Output and Valve Operation
Output (phase)
1 2
ON OFF OFF OFF OFF OFF ON
ø1
ON ON ON OFF OFF OFF OFF OFF
ø2
ø3 OFF OFF ON ON ON OFF OFF OFF
ø4 OFF OFF OFF OFF ON ON ON OFF
LEV Valve Closing and Valve Opening Operations
Valve Closing
Pulse Count
Output states
3 4 5 6 7
Valve Opening
Fully Open
480 pulses
Output pulses change in the following orders when the
Valve is Closed
8
Valve is Open
* 1. When the LEV percentage opening does not change,
ON
all the output phases are off.
2. When the output is out of phase or remains ON
continuously, the motor cannot run smoothly, but move
jerkily and vibrates.
* When the power is switched ON, a 520 pulse valve
opening signal is output to make sure the valve's
position, so that it is definitely at point A. (The 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, it emits a noise.
* Whether a sound is being emitted or not can be
determined by holding a screwdriver, etc. against it,
then placing your ear against the handle.
* If there is liquid refrigerant inside the LEV, the sound
may become lower.
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1→2→3→4→5→6→7→8→1
8→7→6→5→4→3→2→1→8