Delta Electronics VFD-EL Example 5 Use of negative bias in noisy environment, potentiometer range

Chapter 4 Parameters

Example 5: Use of negative bias in noisy environment

In this example, a 1V negative bias is used. In noisy environments it is advantageous to use negative bias to provide a noise margin (1V in this example).

60Hz

54Hz

Pr.01.00=60Hz--Max. output Freq. Potentiometer

Pr.04.00 =10.0%--Bias adjustment Pr.04.01 =1--Negative bias Pr.04.02 =100%--Input gain

Pr.04.03 =0--No negative bias command

Negative0Hz		Gain:100%
		10V Bias adjustment:((6Hz/60Hz)/(Gain/100%))*100%=10.0%
bias 6Hz	0V 1V

Example 6: Use of negative bias in noisy environment and gain adjustment to use full

potentiometer range

In this example, a negative bias is used to provide a noise margin. Also a potentiometer frequency gain is used to allow the Maximum Output Frequency to be reached.

		Bias
60Hz		adjustment	Pr.01.00=60Hz--Max. output Freq.
			Potentiometer
			Pr.04.00	=10.0%--Bias adjustment
			Pr.04.01	=1--Negative bias
			Pr.04.02	=111%--Input gain
			Pr.04.03 =0--No negative bias command
Negative 0Hz			Gain:(10V/9V)*100%=111%
bias 6.6Hz	0V	10V	Bias adjustment:((6.6Hz/60Hz)/(Gain/100%))*100%=10.0%

Example 7: Use of 0-10V potentiometer signal to run motor in FWD and REV direction

In this example, the input is programmed to run a motor in both forward and reverse direction. The motor will be idle when the potentiometer position is at mid-point of its scale. Using the settings in this example disables the external FWD and REV controls.

60Hz FWD		Pr.01.00=60Hz--Max. output Freq.
		Potentiometer
30Hz		Pr.04.00	=50.0%--Bias adjustment
0V 0Hz		Pr.04.01	=1--Negative bias
		Pr.04.02	=200%--Input gain
	5V 10V	Pr.04.03 =1--Negative bias: REV motion enabled
	30Hz	Gain:(10V/5V)*100%=200%
REV
	60Hz

Bias adjustment:((60Hz/60Hz)/(Gain/100%))*100%=200%

Revision August 2008, 2ELE, V1.02 4-55