Panasonic CU-4KE31NBU Control/conditions, Unit operation, Explanation, Heat, Non-stopdefrost

	Control/conditions	Unit operation		Explanation
HEAT	The thermostat turns ON.	The indoor unit is stopped.	The unit operated before, and the temperature of
			the indoor heat exchanger is relatively warm.
			Therefore,the fan speed may start at the set fan
			speed at the same time that the thermostat turns
			ON.
	When defrost operation	Non-stop defrost	Defrost operation begins based on outdoor
	begins, frost has formed		heat exchanger temperature and outdoor
	on the outdoor unit		air temperature conditions.
	(when the ambient air	Indoor fan : Stopped
	temperature is low).	Outdoor fan : Stopped	Non-stop defrost (Refer to Fig. 1)
		Compressor : 80 Hz	1. After HEAT operation begins, the temperature
			of the outdoor heat exchanger is at or below the
		Solenoid valve (for hot gas bypass): ON
			L1 line for 35 minutes.
		4-way valve : Remains ON
			(If outdoor air temperature is less than 26.6 °F,
		Operation lamp : Red and orange ON	the time is 48 minutes)
		alternately	2. After HEAT operation begins, the temperature
			of the outdoor heat exchanger is at or below the
			L2 line for 120 minutes.
			The 4-way valve remains ON during defrost.
			The outdoor fan stops and the solenoid
			valve turns ON, allowing the refrigerant to
			bypass the indoor unit.
			The operating frequency during defrost is
			80 Hz. (Frequency is lowered if the current
			peak cut-off function is activated.)
			The maximum length of a single defrost
			operation is 12 minutes.
			For the outdoor heat exchanger temperature
			conditions for ending defrost, refer to Table 1.
	Defrost release	Indoor fan turns ON.
		After 10 seconds, the solenoid valve
		(for hot gas bypass) turns OFF.
		When the cold air feel has disappeared,
		the indoor fan starts and gradually increases
		speed until it reaches the set speed.
	STOP	All indicator lamps turn OFF. The indoor and
	[Clean defrost]	outdoor units stop.
	Defrost is performed
	when the outdoor unit is
	stopped, and the
	temperature of the
	outdoor unit coil is at or
	below the L1 line.
	(Refer to Fig. 1.)
	Operation is restarted	Starts operating in the same operating mode	Within 4 hours after operation was stopped, it is
	within 4 hours (only when	(HEAT) and with the same temperature	assumed that there has been no significant
	AUTO mode is selected	settings as before operation was stopped.	change in the indoor and outdoor temperatures,
	with the remote		and the previous conditions (HEAT) are stored.
	controller).
	Operation starts after 4	New operation begins based on the
	hours or more have	temperature conditions at the time the
	passed.	ON/OFF button is pressed.

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