Panasonic CU-4KS31NBU service manual Cool

	Control/conditions			Unit operation			Explanation
COOL	The ON/OFF operation		The operation lamp illuminates.			The outdoor unit does not operate for 3 minutes
	button on the remote		The indoor fan operates at the set fan speed.			even after the breaker is turned ON.
	controller is pressed.
			The outdoor unit stops.
			The outdoor unit starts.			The frequency is increased at the rate of 0.5
						Hz every 1 seconds.
			(Compressor and the outdoor fan start.)
			When the frequency reaches Hz,			This is in order to stabilize the return of oil to the
			frequency increases are stopped for a period			compressor.
			of seconds. (Refer to Table 1.)
			The frequency then increases.			If the indoor and outdoor temperatures are high,
						the current peak cut-off activates, stopping
						any increases in frequency.
	The room temperature		The indoor temperature and the desired			Operating frequency is stabilized in order to
	has reached the		temperature are approximately equal.			maintain a comfortable environment.
	desired temperature.
	The thermostat turns					The outdoor unit stops. (It does not stop if the
	OFF.					thermostart for another indoor unit is ON.)
	The thermostat turns		After the thermostat turns ON again, the			After 3 minutes, the outdoor unit begins operating
	ON again.		outdoor unit will not operate for 3 minutes,			automatically.
			even if the room temperature increases			During these 3 minutes, a pressure balance is
			above the desired temperature.
						achieved, allowing the compressor to start
						more easily.
	Freeze prevention		When the temperature of the indoor heat			In order to protect against freezing, the
			exchanger drops to approximately 35.6 °F			compressor stops temporarily, until the
			or below, the compressor turns OFF, the			temperature of the indoor heat exchanger has
			outdoor fan turns OFF, and the indoor fan			risen.
			continues operating with no changes.
			Approximately 3 minutes later, if the
			temperature of the indoor heat exchanger
			is adove 46.4 °F, the system returns to its
			original conditions.
	Stop		All indicator lamps turn OFF. The indoor and
			outdoor units stop.
	Operation is restarted		Starts operating in the same operating mode			Within 4 hours after operation was stopped, it is
	within 4 hours (only when		(COOL) 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 (COOL) are stored.
	controller).
	Operation starts after 4		New operating mode is determined based on
	hours or more have		the temperature conditions at the time the
	passed.		ON/OFF operation button is pressed.
	Frequency control
		(Hz)			(senconds)
				Outdoor air temperature is below 32 °F.		Outdoor air temperature is 32 °F or higher.
		(25) Hz		(120) seconds			(60) seconds
		(35) Hz		(60) seconds			(30) seconds
		(45) Hz		(60) seconds			(30) seconds
		(55) Hz		(180) seconds			(90) seconds

Table 1

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