Sanyo UHX1252, UHX2452, UHX0752, UHX3652, UHX1852 Outdoor Unit Control PCB, Mode. Static signal

PCB and Functions

1. Outdoor Unit Control PCB

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Terminal plug	3P plug (black): For communications circuit impedance matching
	•	A connecting socket (3P, black) is attached to the terminal plug at the time of shipment from
		the factory.
	•	In the case of link wiring which combines the inter-unit control wiring for multiple systems
		into a single communications circuit, leave the connecting socket in place at only one of the
		outdoor units, and move the socket from the "SHORT" side to the "OPEN" side at all other
		outdoor units. If multiple connecting sockets are left in place, communications trouble will
		occur.
LED1, 2	LED (red × 2)
D72, D75	•	LED 1 and 2 blink alternately while automatic address setting is in progress.
	•	Display the alarm contents for alarms which were detected by the outdoor unit.
Power LED	LED (red): Power indicator
D53	Indicates the DC 5V power on the outdoor unit control PCB.
Run	2P plug (white): Start pin
(CN103)	Short-circuit this pin and apply a pulse signal to start all indoor units in that refrigerant system.
Stop	2P plug (white): Stop pin
(CN104)	Short-circuit this pin and apply a pulse signal to stop all indoor units in that refrigerant system.
AP	2P plug (white): Vacuuming pin
(CN102)	•	To perform vacuuming of the outdoor unit, short-circuit this pin and then turn the power ON.
		All solenoid valves turn ON and vacuuming begins smoothly. (Do not perform automatic
		address setting at this time.)
	•	Release the short-circuit to return the unit to normal status.
Mode	2P plug (white): Indoor unit Heating/Cooling mode change pin
(CN101)	•	When operating the compressors to perform automatic address setting, operation in Heating
		mode can be normally used. However, short-circuiting this pin performs operation in Cooling
		mode. (Static signal)
	•	Short-circuiting this pin during ordinary operation changes the mode from Cooling to
		Heating (if the current mode is Cooling) or from Heating to Cooling (if the current mode is
		Heating).
Test	2P plug (white)
(CN022)	•	This pin is used to test the PCB at the factory.
	•	When the power is turned ON after this pin has been short-circuited, all output signals will
		be output in sequence. (Sequential output does not occur if this pin is short-circuited when
		the power is already ON.) Releasing this pin returns the unit to normal control.

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