Toshiba CONCEALED DUCK TYPE, CEILING TYPE service manual Tcj, Tcn, Tc n, Conditions

No.	Item	Outline of specifications			Remarks
8	Freeze preventive control	1) The cooling operation (including Dry operation) is			Tcj:
	(Low temperature release)	performed as follows based on the detected			Indoor heat exchanger
		temperature of Tc sensor or Tcj sensor.
					sensor temperature
		When [J] zone is detected for 6 minutes
		(Following figure), the commanded frequency is
		decreased from the real operation frequency.
		After then the commanded frequency changes
		every 30 seconds while operation is performed in
		[J] zone.
		In [K] zone, time counting is interrupted and the
		operation is held.
		When [ I ] zone is detected, the timer is cleared
		and the operation returns to the normal operation.
		If the commanded frequency becomes S0
		because the operation continues in [J] zone, the
		return temperature A is raised from 5°C to 12°C
		until [ I ] zone is detected and the indoor fan
		operates with [L] mode.
		˚C
		5	I	A
			K
		2	J
		In heating operation, the freeze-preventive control			Tcn:
		works if 4-way valve is not exchanged and the			Tc temperature when 5
		following conditions are satisfied.			minutes elapsed after
		(However the temperature for J zone dashing control			activation
		is changed from 2°C to –5°C.)			Tc (n – 1):
		<Conditions>
					Tc temperature at start
		• When Q or R is established 5 minutes after
					time
		activation.
		QTcn ≤ Tc (n – 1) – 5
		RTcn < Tc (n – 1) – 1 and Tcn ≤ Ta < 5°C

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