Toshiba RAV-SM803AT-E Discharge temperature release control, Current release control

9-2-2. Outline of Main Controls

1.Pulse Modulating V alve (PMV ) control

1)For PMV with 50 to 500 pulses during operation, respectively.

2)In cooling operation, PMV is controlled with the temperature difference between TS sensor and TC sensor.

3)In heating operation, PMV is controlled with the temperature difference between TS sensor and TE sensor.

4)For the temperature difference in items 2) and 3), 1 to 5K is aimed as the target in both cooling and heating operations.

5)When the cycle excessively rose in both cooling and heating operations, PMV is controlled by TD sensor.

The aimed value is usually 103°C for SM56, SM80 and 100°C for SM110, SM140 in both cooling and heating operations.

REQUIREMENT

A sensor trouble may cause a liquid back-flow or abnormal overheat resulting in excessive shortening of the compressor life. In a case of trouble on the compressor, be sure to check there is no error in the resistance value an the refrigerating cycle of each sensor after repair and then start the operation.

2. Discharge temperature release control
1)	This function controls the operation frequency, that	TD [˚C]
	is, lowers the operation frequency when the
	discharge temperature has not lower or the	Error stop ("P03" display with 4 times of error counts)
	discharge temperature has rapidly risen during
		a
	PMV control. It subdivides the frequency control
	up to a unit of 0.6 Hz to stabilize the cycle.	Frequency down
2) When the discharge temperature is detected in an		b
	abnormal stop zone, the unit stops the compres-	c
	sor and restarts after 2 minutes 30 seconds. The	Frequency holding
	error counter is cleared when it has continued the
	operation for 10 minutes.	d
	If the abnormal stop zone has been detected by 4	Frequency slow-up
	times without clearing of counter, an error “P03” is
		(Up to command)
	displayed.	e
	* The cause is considered as excessively little	As command is
	amount of refrigerant, defective PMV, or clogging
	of cycle.

					[°C]
	a	b	c	d	e
SM56, SM80	117	107	103	100	93
SM110, SM140	111	106	100	95	90

3.Current release control

The output frequency and the output voltage are controlled by AC current value detected by T02 on the outdoor P.C. board so that input current of the inverter does not exceed the specified value.

Current [A]
	Frequency down
I1	Hold
I1–0.5	Hold
	Normal operation

Objective model	SM56		SM80		SM110		SM140
	COOL	HEAT	COOL	HEAT	COOL	HEAT	COOL	HEAT
I1 value [A]	10.1	12.0	12.2	14.0	18.9	19.7	19.7	19.7

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