# VFD wiring question



## Chuck K (Oct 30, 2013)

I'm trying to run my Sheldon lathe with a Huanyang vfd.  My question pertains to wiring a remote pot to it.  I have it working well with a remote f/r switch and e-stop button while controlling the frequency from the panel.  I can't get the pot to work correctly though.  I probably have it hooked up wrong or I'm missing a parameter, although I've been through them a few times.  When I have it hooked up and the 003 parameter set to 1, I get some control with the pot, but it runs at real low frequency and the adjustment of the pot is limited. I bought the pot from Mcmaster-carr.  It's a 10K pot.  I would appreciate any suggestions.  Here's some pics of the vfd and pot.

Chuck


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## Ray C (Oct 30, 2013)

There are three leads on the pot.  One of them is the wiper and it has variable resistance.  The other two wires should always read about 10k.  Test with an Ohm meter and make sure you haven't got the wires mixed up.  On the schematic, the wire that shows the arrow is the wiper (VI).  It goes in the center of the three connections.  

EDIT:  Also, you're using the 5V input on one of the leads.  The schematic shows the input as 10/5 (10 or 5) volts input.  For a 10k pot, use the 10v input.  You would use the 5v input if you had a 5k variable pot.



Ray


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## Chuck K (Oct 30, 2013)

Ray C said:


> There are three leads on the pot.  One of them is the wiper and it has variable resistance.  The other two wires should always read about 10k.  Test with an Ohm meter and make sure you haven't got the wires mixed up.  On the schematic, the wire that shows the arrow is the wiper (VI).  It goes in the center of the three connections.
> 
> EDIT:  Also, you're using the 5V input on one of the leads.  The schematic shows the input as 10/5 (10 or 5) volts input.  For a 10k pot, use the 10v input.  You would use the 5v input if you had a 5k variable pot.
> 
> ...


Thanks Ray.  That pretty much agrees with everything I've found doing a google search on it tonight.  I tried several different combinations of terminals...but being electrically challenged I was pretty much just guessing.


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## CluelessNewB (Oct 30, 2013)

1) Make sure the wiper of the pot is hooked to VI and not one of the ends.
2) PD002 set to 1 (I suspect you meant PD002 not PD003?  I would think you want PD003 set to 60.0 by default)
3) PD070 set to 1 (since you are using 5V on one end of pot) if you change to 10V set PD070 to 0 

So my guess is you can either:
 1)  change to 10V and use the default (0) for PD070
  OR
 2)  leave it using 5V and change PD070 to 1


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## CluelessNewB (Oct 31, 2013)

intrepid said:


> Chuck,
> My guess is you have everything wired correctly.  I had the same problem with the same VFD.  With the help of another member, rangerjoe, we found there is another parameter that needs to be changed.  It's farther down the list and without my manual in front of me, I'm not sure.  Maybe parameter 70 or 72, if I remember correctly it also deals with max Hz.  Without changing it I could not get over 50 Hz.  If you don't find it I search for my manual in the morning.  good luck,
> danny



Yes I forgot about that PD072 sets the max Analog Frequency, manual says default is 50 which would limit you to about 80% of normal max speed.  On mine it came set at 60 so it wasn't an issue but that's not the only discrepancy I found in the manual.


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## Ray C (Oct 31, 2013)

Yeah, I have one of those units and had the same issue but in my case, I had both 5 and 10K pots available and whichever one I grabbed, I happened to use the wrong voltage and it wasn't getting enough current to drive the speed control.  I do indeed remember some settings for that but have since forgotten.  If this problem persists, I'll go dig-up the manual and look it over.


Ray


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## strantor (Oct 31, 2013)

Chuck K said:


> Thanks Ray.  That pretty much agrees with everything I've found doing a google search on it tonight.  I tried several different combinations of terminals...but being electrically challenged I was pretty much just guessing.



Be careful doing that; if you have the wiper and one of the ends crossed, and you go all the way to one end of the pot, you can short the + to the -...

I don't know anything about huyangyang VFDs or their capability to withstand a direct signal short, but I learned this lesson on an older spectrum DC drive - the pot + doesn't like to be shorted to the pot -, it will stop working. 

I say this not to kick sand in your eye when you're obviously already done doing what you were doing, but so that you have something to look for - make sure you still have 10V output for the pot. You might have had a parameter issue initially, but once you get that worked out, if it still doesn't work, you might have a hardware issue.


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## Chuck K (Oct 31, 2013)

Ok....I thought I replied to this earlier, but I guess I forgot to hit send...or it's going to show up right after I post this one.  I changed the wiring and parameters today and the pot works now.  The only issue is the sensitivity of the pot.  It adjusts from 0 to 70 hz like I want but it does it in half a turn instead of a full turn.  I probably missed some intermediate parameter or something.  It makes the lathe a lot more user friendly.  This is the first time I've used a vfd and not had the annoying high pitched whine.  On a different subject...I reworked the new 3 jaw chuck I bought for this lathe the way Ray suggested in an earlier thread.  I have always cut the mounting plate for a tight fit on the chuck.  I took it back apart and cut the spigot about .020 undersized.  I mounted the chuck on it with the bolts just snugged and then dialed it in and torqued the bolts.  It's running just about dead nuts now.  It's still a cheap chuck that doesn't adjust real smooth, but it runs true. )  Thanks Ray.

Chuck


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## Ray C (Oct 31, 2013)

Chuck,

There are linear and non-linear pots.  You could get a different pot that will have more of a uniform reaction when you turn the dial but, you're not losing out or damaging anything with the one you have.  Mine does the same thing as yours.  One thing to keep in mind, is that if you turn the pot all the way down then, stop the machine, it might not start up until you crank the dial up a little...

... The chuck... It will loosen-up over time and operate smoothly.  -Until you get some swarf stuck in the scroll and then it's time to remove the jaws and (carefully) blow-out the crud.


Ray





Chuck K said:


> Ok....I thought I replied to this earlier, but I guess I forgot to hit send...or it's going to show up right after I post this one.  I changed the wiring and parameters today and the pot works now.  The only issue is the sensitivity of the pot.  It adjusts from 0 to 70 hz like I want but it does it in half a turn instead of a full turn.  I probably missed some intermediate parameter or something.  It makes the lathe a lot more user friendly.  This is the first time I've used a vfd and not had the annoying high pitched whine.  On a different subject...I reworked the new 3 jaw chuck I bought for this lathe the way Ray suggested in an earlier thread.  I have always cut the mounting plate for a tight fit on the chuck.  I took it back apart and cut the spigot about .020 undersized.  I mounted the chuck on it with the bolts just snugged and then dialed it in and torqued the bolts.  It's running just about dead nuts now.  It's still a cheap chuck that doesn't adjust real smooth, but it runs true. )  Thanks Ray.
> 
> Chuck


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## CluelessNewB (Oct 31, 2013)

There are two popular styles of pots, "linear" taper and the more common "audio" (logarithmic)  taper.  For a VFD you really want a linear taper pot to get smooth control across the entire range.  


More info from Wikipedia:
http://en.wikipedia.org/wiki/Potentiometer


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## Chuck K (Oct 31, 2013)

I was under the impression that the one I bought was a linear pot.  I got it from macmaster carr.  Part # 7436K37.   I called Radio Shack locally, but it sounded like the one they had wasn't the kind I wanted.  In any case, it works, and if I decide I can't live with it I can address it later.  Thanks

Chuck


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## davemm (Nov 13, 2013)

Just saw your post and realised that I have a similar vfd with an external pot added. Reckon I had a similar experience with the pot when I first installed it till I realised there is a jumper block at the end of the control circuit connector that must be moved to use an external pot properly (at all?) Page 10 of my manual if you have the same one

Dave


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