Delta Electronics VFD-M manual

Chapter 4 Parameters

Example 5:

In this example, a 6 Hz (10% of 60 Hz) negative bias is used. This setting is used to provide a noise margin (1V in this example) in noisy environments. Note that the top frequency is reduced to 54 Hz.

Max.

Output Pr.03

Freq.

60Hz

54Hz

0Hz

Negative

Factory Settings

Pr.03=60Hz--Max. output Freq. Pr.48=10.0% -- bias adjustment Pr.49=1 -- bias polarity Pr.50=100% -- pot. freq. gain Pr.51=0 -- Rev. motion disable in negative bias

	24
It's 0Hz
within 0
this	Hz 54
range.
0V	10V

bias 6Hz 0V 1V

Example 6:

10V Potentiometer Scale

This example also uses negative bias and includes a potentiometer frequency gain to allow the AC drive to reach the Maximum Output Frequency.

Max.

Output Pr.03

Freq.

60Hz

0Hz

Negative 0V bias 6.6Hz

Example 7:

Bias adjustment

	Factory Settings
	Pr.03=60Hz--Max. output Freq.
	Pr.48=10%--bias adjustment
	Pr.49=1 -- bias polarity
	Pr.50=111% -- pot. freq. gain
	Pr.51=0 -- REV. motion disable
	in negative bias
10V	Calculation of gain
	Pr.50=(	10V	)X100%=111%
		9V

	27
It's 0Hz
within 0
this		60
range.	Hz
		10V
0V

Potentiometer Scale

In this example, the potentiometer is programmed to run a motor in forward or reverse direction. The motor will idle when the potentiometer is set at the scale mid-point. Please note that this adjustment will disable the external FWD and REV controls.

Pr.03	Max.Output Freq.
60Hz	FWD		Factory Settings
30Hz			Pr.03=60Hz--Max. output Freq.
0V 0Hz
			Pr.48=50%--bias adjustment
	5V	10V	Pr.49=1 -- bias polarity
	30Hz		Pr.50=200% -- pot. freq. gain
REV			Pr.51=1 -- REV motion disable
	60Hz		in negative bias

0

REV. FWD.

60	Hz	60
0V		10V

Potentiometer Scale

4-46 Revision May 2008, ME14, SW V3.04