Toshiba RAS-10YKV-E, RAS-13YKV-E Prevent-FreezingControl, 8-1-5.P. M. V. Pulse Modulating Valve

8-1-4. Prevent-Freezing Control

The indoor heat exchanger sensor detects refriger- ant vapor temperature in COOL/DRY operation.

If the temperature is below the specified value, compressor motor speed is reduced so that opera- tion is performed in temperature below the specified value to prevent-freezing of indoor heat exchanger.

8-1-5. P. M. V. (Pulse Modulating Valve)

Using P.M.V., refrigerant flow of refrigeration cycle is varied for the optimum temperature. Controlling each unit separately by two P.M.V. corresponds to difference of pipe length, fan speed, and unit tem- perature.

After the power has been turned on, when a serial operation signal is received from indoor at the first time, or when PMV alarm is detected and the equipment is reactivated, move the valve once until it hits on the stopper for positioning of the valve.

In this case, ticktack sound may be heard.

8-1-6. Louver Control

(1)Vertical air flow louvers

Positions of vertical air flow louvers are auto- matically controlled according to the operation status (AUTO, COOL, DRY, HEAT). Besides, positions of vertical air flow louvers can be arbitrarily set by pressing the [SET] button. The louver position which has been set by the [SET] button is stored in microcomputer, and the louver is automatically set at the stored position in the next operation.

(2)Swing

If the [AUTO] button is pressed during running operation, vertical air flow louvers start swinging. When the [AUTO] button is pressed again, swinging stops.

8-1-7. Indoor Fan Control (DC Fan Motor)

The indoor fan is operated by motor speed non-step variable DC drive system motor. For flow rate, motor speed is controlled manually in three steps (LOW, MED, HIGH), and with the unit of 10 rpm from upper limit to lower limit in AUTO mode as described in Table 8-1-2. It is not selected by relay, so selecting sound does not generate.

Table 8-1-2

Operation

mode

COOL

DRY

HEAT

	RAS-10YKV-E		RAS-13YKV-E
Fan mode
	Motor speed	Air flow rate	Motor speed	Air flow rate
	(rpm)	(m³/h)	(rpm)	(m³/h)
H	1120	480	1210	530
M	980	400	1020	420
L	850	330	850	330
—	820	320	820	320
H	1200	520	1270	560
M	1070	450	1100	470
L	930	380	930	380

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