Toshiba VF-A7 instruction manual  Overload reduction start-up  ～ Hz,  ×1.0 ×0.6

[Example of setting: VF-A7 2007PL with a 0.4 kW motor (rated current: 2A)]

Key operated

LED display

Operation

			The running frequency is displayed. (Make this setting when the
			motor is out of operation.)(If the monitor display mode setting
			parameter  is set at [Running frequency])
	MON		Press the MON key to call up the first basic parameter
			(automatic acceleration/deceleration).
▲	▼		Switch to (extended parameters of from  to
			) by pressing the △ or ▽ key.
	ENT		Press the Enter key to call up the parameter 
			(electronic thermal motor protection level 1).
	ENT		Press the Enter key to display the parameter setting (set
			value). (Default setting:  %)
▲	▼		Change the parameter setting to
			 = (motor's rated current/inverter's rated output
		
			current) x 100
			= 2.0/5.0 x 100)
	ENT	⇔	Press the Enter key to save the change. Then, 
			and the set value are displayed alternately.

[VF motor (motor intended for use with an inverter)]

■Setting the electronic thermal protective function 

Set value	Overload protection		Overload stall
	protect		not	stall
	protect		stall
	not	protect	not	stall
	not	protect	stall

VF motors (intended for use with an inverter) can be operated in lower frequency ranges than general-purpose motors. If a VF motor is operated in an extremely low frequency range, however, its cooling efficiency drops. In such a case, set the OL reduction start frequency parameter  according to the characteristics of the motor. (See the figure below.)

As a guide, it is advisable to set this parameter around the default value (VF motor 6Hz).

Title	Function	Adjustment range	Default setting
	Overload reduction start-up	～ [Hz]	
	frequency

Note)  is enabled when  is set at , , , or .

■Setting the motor overload protection level #1 

When the inverter is used for a motor with a capacity or a current rating smaller than that of the inverter, it is necessary to adjust the motor overload protection level #1 parameter  according to the rated current of the motor.

When the output current is displayed in %,100% corresponds to the rated output current of the inverter.

Output current reduction rate [%]

 ×1.0



×0.6

Setting of motor overload start level ０



＝ 6.0 Output frequency [Hz]

E-26