Toshiba VF-A7 instruction manual Prohibiting the reverse operation,  ：Reverse-run prohibition

☆The ratio of the voltage to the frequency can be adjusted to the motor capacity. Setting  at  enables the inverter to prevent the output voltage from increasing with the input voltage when the operation frequency is higher than the base frequency.

[=: no voltage compensation/not limited]

Input voltage

[=: voltage compensation/not limited]

Input voltage

high

 ×inputvoltage Rated voltage

Output voltage

[V]

0 Output frequency ＊＝, , 

high

low




Output	low
voltage
[V]

0 Output frequency 

＊The output voltage can exceed  if the output

	＞1: no voltage higher than
Rated voltage
	the input voltage is put out.

frequency is higher than the base frequency ##, even when  is lower than the input voltage.

[=: no voltage compensation/limited]

	input					Input voltage
							high
	×voltage
Rated voltage							low
	Output
	voltage
			[V]
			0
				Output frequency
						
	＊＝, , 
					＞1, no voltage higher than
		Rated voltage
					the input voltage is put out.

[=: voltage compensation/limited]

			Input
			voltage
			high
Output			low
voltage
[V]
0
	Output frequency	

6.13.7 Prohibiting the reverse operation

 ：Reverse-run prohibition

・Function

The function prevents the direction of operation from being reversed in case an in correct operation signal is given.

[Parameter	setting]
Title	Function	Adjustment range	Default setting
	Reverse-run	: Permitted, : Reverse run prohibited : Forward run prohibited,	
	prohibition	: Direction designated by command permitted(*1)

(*1): Top priority is given to the command specifying the direction of rotation (forward run or reverse run command).In preset-speed operation mode or forced jog run mode, you can prevent the motor from rotating in the opposite direction to that specified by the forward run or reverse run command.

Caution!

･This parameter is invalid in positioning mode. In addition, if the motor runs in a prohibited direction in preset-speed mode or forced jog run, operation commands become invalid irrespective of the control mode.

･If the motor constant is not set optimally in vector-control, automatic-torque boost mode, the motor may slightly run in reverse direction because of the slip frequency. Before using this parameter, set parameter  (stop frequency) at a frequency close to the slip frequency. When the inverter is in sensor vector control mode ( =  and  = ), depending on the setting of , the motor may rotates in the opposite direction to that prohibited when it is turned off and then on again, regardless of the setting of this parameter.

F-30