Mitsubishi Electronics PUY-A18NHA2-BS, PUZ-A42NHA2-BS Output pulse signal and the valve operation

Linear expansion valve (A12, 18)

(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 indoor controller board and the linear expansion valve>

Outdoor controller board

DC12V

LEV Red 1

3

M 2

15

6 4

	Brown	2
[4	Blue	3
[3	Orange	4
[2	Yellow	5
[1	White	6

Connector LEV-A

Drive circuit

[4

[3

[2

[1

<Output pulse signal and the valve operation>

Output				Output
(Phase)	1	2	3	4	5	6	7	8
[1	ON	ON	OFF	OFF	OFF	OFF	OFF	ON
[2	OFF	ON	ON	ON	OFF	OFF	OFF	OFF
[3	OFF	OFF	OFF	ON	ON	ON	OFF	OFF
[4	OFF	OFF	OFF	OFF	OFF	ON	ON	ON

(2) Linear expansion valve operation

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 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.)

Valve position (capacity)

			When the valve moves smoothly, there is no sound or vibration
		C	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 dri-
			ver handle while putting the screw driver to the linear expansion
Close	Open		valve.
	500 pulse
A	Opening a valve
	all the way
B	Pulse number

Extra tightning (about 32 pulse)

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