change output 4-20 to 0-10

Hi......


I need your help i have a problem with a vfd from a cutter.... the motor is running at speed make the set poin from the panel view but one hour or more latter the speed goin to the max...... i change the control speed to the him from vfd and i have no problem with the speed dont going up any more im using this output card 1746-in04vi at 4-20 to the vfd analog input...

How can check the card or how can change de output to 0-10 v??

I hope your comments soon and thanks for all....

Is this card a Spectrum Controls product? ( 1746sc-INO4vi )

If so see link to the manual if you don't have it. You will need to changed the wiring on the card and its configuration to get voltage instead of current.

But why do you want to change from current to voltage?

http://www.spectrumcontrols.com/pdfs/abio/1746sc_INO4_manual_0300128-03_D.pdf

The control signal out of the PLC must match the control signal setting into the VFD. Most VFDs can be configured to take either a 0-10 VDC or a 4-20 mA signal. This usually requires both wiring to the correct terminals and configuration of the drive to follow the required signal. In my experience VFDs will track the input command quite accurately. Check your configuration and wiring, and then try changing the signal to verify proper tracking.

hi mike.

I'm thinking of changing the voltage for the problem I'm having with the vfd ... that increases the maximum speed and the panelview have a different... for example in the panel I have a speed of 35 and the vfd is running at that speed but then the speed is increased himself by the vfd go the maximum 60 and I can not lose ....and i change the speed control to the vfd him ... and the problem has not recurred ...

I do not understand what exactly you are talking about... may be my English...

I'm thinking of changing the voltage for the problem I'm having with the vfd ... that increases the maximum speed

Click to expand...

that does not increase maximum speed. Speed range is set in VFD, either 0-10V or 4-20Ma controls between that setting, it should make no difference.

for example in the panel I have a speed of 35 and the vfd is running at that speed but then the speed is increased himself by the vfd go the maximum 60 and I can not lose

Click to expand...

I don't think the speed increases by itself...

...and i change the speed control to the vfd him ... and the problem has not recurred ...

Click to expand...

Ok this I don't understand. what is "vfd him"? and what do you change there, max speed? (that wouldn't solve the problem)
Again, speed doesn't change by itself. How do you make sure the program doesn't change the analogue output? Or does the analogue output change at all? measure...

I would look for something in the program, besides the operator display input, which is changing the analog output. Changing from current to voltage will not affect an actual change in output.

'VFD HIM' - some drives have an interface on the drive itself with varying levels of information. 'peppin23joe' is saying that when he changed control of the speed from an external input to the drive's front display the speed stayed stable.

Work backward. Measure current coming in VFD all the time and see if it goes high after some time. If it does, check analog output reference from card. If AO is commanding speed check what makes it happen...it seems something is bypassing HMI control.