Mitsubishi Electronics PMFY-P12NBMU-E1 Output Phase, Linear expansion valve operation

<Output pulse signal and the valve operation>

Output		Output
(Phase)	1	2	3	4
{1	ON	OFF	OFF	ON
{2	ON	ON	OFF	OFF
{3	OFF	ON	ON	OFF
{4	OFF	OFF	ON	ON

2Linear expansion valve operation

Closing a valve : 1 → 2 → 3 → 4 → 1

Opening a valve : 4 → 3 → 2 → 1 → 4

The output pulse shifts in above order.

•When linear expansion valve operation stops, all output phase become OFF.

•At phase interruption or when phase does not shift in order, motor does not rotate smoothly and motor will lock and vibrate.

		D	C
(capacity)
position		Close
Valve		Open
			2000 pulse
	A		Opening a valve
	E		all the way
	B	Pulse number

•When the switch is turned on, 2200 pulse closing valve signal will be send till it goes to point A in order to define the valve position.

•When the valve moves smoothly, there is no sound or vibration occurring from the linear expansion valves : however, when the pulse number moves from E to A or when the valve is locked, more sound can be heard than in a normal situation.

•Sound can be detected by placing the ear against the screw driver handle while putting the screw driver tip to the linear expansion valve.

Extra tightening (80~100pulse)

3Trouble shooting

Symptom				Check points		Countermeasures
Operation circuit fail-	Disconnect the connector on the controller board, then con-					Exchange the indoor con-
ure of the micro	nect LED for checking.				6	troller board at drive circuit
processor					5	failure.
					4
					3
					2
				1k" LED	1
	When power is turned on, pulse signals will send for 10
	seconds. If the LED does not light or keeps lighting even
	after the signals stop, that means some failures in the
	operation circuit.
Linear expansion	Motor will idle and make a ticking noise when the motor is					Exchange the linear
valve mechanism is	operated while the linear expansion valve is locked. This					expansion valve.
locked.	ticking sound is the sign of the abnormality.
Short or breakage of	Measure the resistance between each coil (white-red, yellow-					Exchange the linear
the motor coil of the	brown, orange-red, blue-brown) with a tester. It is normal if					expansion valve.
linear expansion	the resistance is in the range of 150Ω ±10%.
valve
Valve doesn't close	To check the linear expansion valve, operate the indoor unit					If large amount of refriger-
completely.	in fan mode and at the same time operate other indoor units					ant is leaked, exchange
	in cooling mode, then check the pipe temperature <liquid					the linear expansion valve.
				pipe temperature> of the indoor unit by the
				outdoor multi controller board operation
				monitor. During fan operation, linear
			Thermistor	expansion valve is closed completely and if
			(Liquid pipe)	there is any leaking, detecting temperature
		Linear		of the thermistor will go lower. If the detect-
		expansion		ed temperature is much lower than the tem-
		valve		perature indicated in the remote controller,
	it means the valve is not closed all the way. It is not neces-
	sary to exchange the linear expansion valve, if the leakage is
	small and not affecting normal operation.
Wrong connection of	Check the color of lead wire and missing terminal of the con-					Disconnect the connector
the connector or	nector.					at the controller board,
contact failure						then check the continuity.

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