Control Terminal Input: Up and Down Functions

[vinic]

My application for AC drives requires a direct up and down frequency control. So far, there are two drive manufacturers that seem to have this feature; Saftronics (Fuji) and Yaskawa. I'd like to open my options to using other brands.

For an example of the function being used, on a Saftronics CV10 the S3 and S4 terminals are set with parameters 5-02 and 5-03 allowing the frequency to be adjusted up and down by closing a dry contact circuit (pg 45 of manual). The rate of change is then adjusted using the acceleration and dec. functions.

It was suggested in another thread that this type of function is available on 'most any drive these days. Either it wasn't understood exactly what function I was using, or I'm missing something, as this type of function does not seem to be available on most drives.

Any help (especially examples for specific drives.. like AC Tech) would be greatly appreciated.

Thanx,

Clyde Gill

 

[jraef]

vinic,
Many VFDs have this feature, but the problem you will find (or already have found) is that they describe it in different ways.

One of the more common descriptions to look for is the "Up / Down" speed control option you described, but it is sometimes listed as a programmable setting for the digital inputs and other times as a feature of the Speed Command reference. That is how it is shown for Motortronics CSD Series VFDs.

Another term is "Motorized Pot Input" (or control). The concept behind that is simulationg the action of an old-style motor operated potentiometer, where you pushed one button to run the pot to the right, another to run it to the left. That is how it is described in the Motortronics ALX Series VFDs.

So as you can see, even within the same company different engineers use different terms to describe it. It just takes some clever snooping (or a decent applications engineer) to find it.

"Venditori de oleum-vipera non vigere excordis populi"

 

[vinic]

Thanx jraef,

That's very helpful. I've been tempted to pick up some used drives to "snoop" around them to see if they will work.

One of the other ideas I've had but not acted on, was setting up a solid state potentiometer to drive the pot option. These devices are tiny, and working with them is a bit out of my range of skills.. but if I have to...

In the long run, if it's just nomenclature, learning that aspect would be the route to take.

Thanx again.

clyde

 

[fornhamspark]

you might want to look at ABB Acs range, or Mitsubishi.

Both of these drives have this option via the digital inputs to speed up or down from say two pushbuttons

 

[Marke]

Control Techniques, Emotron, Danfoss all have the motorised pot option. I do not expect that it will be a problem finding a drive that can do this.
I would suggest the the thing that separates a lot of different drives, is the ease of making these functions work.
Some drives are almost intuitive and with a little help from the manual, you can do it your self, while others require a trained and skilled technician/engineer to achieve the same result.
Some can be easily set up from the front panel programmer/display, others require the use of a dedicated software package and computer.

Best regards,

Mark Empson

http://www.lmphotonics.com

 

[DickDV]

It's the terminology here that is confusing things. I've seen this function called MOP (Motor Operated Pot) and "Floating Point" speed control.

Pretty much every drive manufacturer has to have this feature available somewhere in their product because its the only convenient way of getting full-range speed control from multiple operator stations.

 

[vinic]

Bingo DickDV,

I cannot thank you enough!!

I'm seeing functions listed as "MOP" for both decrease and increase frequency in the AC Tech drive manual, pgs 36 and 37 (Adobe Reader pages), both functions set to "05" for TB 13b and c respectively (note to self!).

That otta doer.

I'll be looking into the other drives listed by Marke and fornhamspark too.

Thanx all!


If any of you are ever in South Central Missouri, stop on in and I'll treat you to a glass of wine!! Just mention this thread.

Clyde Gill

http://www.PeacefulBend.com

 

[Skogsgurra]

And Siemens has it too. In all their drives.