VFD speed control

whateg0 · Jul 12, 2017

I'll start by saying that I bought a cheap VFD off of ebay, but it seems to work aside from the lack of braking resistor capability. But it was long after I bought it before I was at the stage in the project to realize it, so it is what it is.

That aside, I am using this on a lathe with a 2 hp motor. I can set the speed fine from the control panel. When controlling it via the 0-5V input, I have some issues. There are settings for accel/decel rates, but those don't seem to apply to an external input, so changing the frequency rapidly results in an over-voltage or over-current condition depending on which way I go.

I am looking at alternatives, but I've not really found much information on whether this is typical behavior. If it is, then there's really no point in spending money on another VFD. (Ok, it would be good to have a braking resistor so I can stop the spindle a bit more quickly.) I have drawn up a conditioning circuit that should do well to prevent these errors in most circumstances, so replacing the VFD isn't a real requirement at this point. So, do other VFDs also depend on the control voltage rate of change being limited, or do they apply the accel/decel values to whatever is controlling them?

JST · Jul 12, 2017

Ones I am aware of do control accel/decel rate no matter where the input comes from. It's probably MORE important to control the user input, because Bubba will twist the knob too fast.

What kind of VFD do you have?

As you have probably found, a resistor/capacitor circuit can slow down the input and prevent trip-outs.

whateg0 · Jul 12, 2017

As an electronics tech, yeah, I planned on using a resistor/capacitor to slow the voltage change.

This is the VFD I bought. 135251 | eBay

I knew it was cheap and didn't expect all the bells and whistles that a more expensive one would have. I did think I was getting the ability to add a braking resistor because the ad says so, but that is clearly not the case. Further research after the fact revealed others who have also been fooled. I'm not above opening it up and adding the connections and circuitry to use a braking resistor, but so far I gotten by with DCIB and reasonable decel times.

On that note, I may not have made it clear before, but the accel and decel times to apply to start and stop, just not freq changes. And now I wonder if that is true for the front panel, too, after all. I never changed it fast from the front panel like I do in use. I guess I need to go look at that to see. I had not considered that it might not apply any accel/decel values to changes.

JST · Jul 12, 2017

That looks like the notorious "Huanyang" unit. There may be a setting for it.

rons · Jul 12, 2017

You best bet is to set the VFD to 60Hz and just assume it is a standard 3 phase source. Make all you control decisions with what was built into the lathe. Life is better.

ignator · Jul 12, 2017

Have you set the drive for 2HP operation? The drive needs this information for overload and for it's tuning algorithms (they derive motor constants from this).
I've fought this same problem with name brand drives, using the speed knob on the drive.

whateg0 · Jul 12, 2017

ignator said:
Have you set the drive for 2HP operation? The drive needs this information for overload and for it's tuning algorithms (they derive motor constants from this).
I've fought this same problem with name brand drives, using the speed knob on the drive.

JST said:
That looks like the notorious "Huanyang" unit. There may be a setting for it.

I've not found any settings for the motor size. In fact, compared to the list of settings I found on other VFDs, this thing isn't much more than on/off! I think the list of Pn numbers goes to 32. There is only one set of settings for accel/decel. Using DC braking with only like 5V gets me stopped from about 20 Hz pretty quickly, but anything over that, I still get overvoltage errors, which is to be expected, I suppose. I haven't removed the rotor driven fan from the motor yet and replaced it with an independent fan, so I am trying to be conservative on things like DC braking. This VFD also doesn't seem to apply the DC braking at the last few Hz, but rather as soon as the FWD/REV signal is removed. Then it applies it for a set number of seconds. I have that set to only 1 second right now.

whateg0 · Jul 12, 2017

rons said:
You best bet is to set the VFD to 60Hz and just assume it is a standard 3 phase source. Make all you control decisions with what was built into the lathe. Life is better.

If I just wanted a single speed motor, I could have installed one of the several 2 hp single phase motors. The idea behind the VFD was to regain variable speed.

JST · Jul 12, 2017

The standard Huanyang has a ton of settings.

BUT there are a bunch of special purpose versions with a totally different control program that are being sold on EBAY. That sounds like it is one, if it has only 32 parameters. Might be a high speed spindle version, someone else had one of those, and it had hardly any settings,most of the usual ones like motor current were missing.

If so, I am sorry to say, you may have "gotten took", and there may just be no way from here to what you want with that unit.

Do you have a link to a manual?

I swore I would class the Huanyang with the rest of the prohibited chinese hobby machines and close the threads, but I never seem to have the heart to do it..... as in this case.

whateg0 · Jul 12, 2017

JST said:
The standard Huanyang has a ton of settings.

BUT there are a bunch of special purpose versions with a totally different control program that are being sold on EBAY. That sounds like it is one, if it has only 32 parameters. Might be a high speed spindle version, someone else had one of those, and it had hardly any settings,most of the usual ones like motor current were missing.

Is it that there are special versions? Or are some just imposters?

JST said:
If so, I am sorry to say, you may have "gotten took", and there may just be no way from here to what you want with that unit.

Yes, I think I did get taken for a ride.

JST said:
Do you have a link to a manual?

No. I keep meaning to bring it in from the shop and scan all 4 pages of it. Ok, there are more than 4. But it probably prints in booklet form on 4 sheets. I'll try to remember to do that when I go back out to the shop later tonight.

JST said:
I swore I would class the Huanyang with the rest of the prohibited chinese hobby machines and close the threads, but I never seem to have the heart to do it..... as in this case.

I didn't really intend this thread to be about my VFD. I really just wanted to find out how other, "more legitimate" units work. I don't want to buy another thinking I'm getting away from a problem to find out that they all work that way and I just have to find a different way of handling the control side. Sorry it went in that direction.

JST · Jul 12, 2017

They seem to have sold special versions to various companies, with just the control parameters the customer wanted. Obviously if the target was a specific motor, there is no need to be able to set motor parameters, that is all known, and the user should not mess with those, so they are not provided..

I have some Huanyang PDF manuals, and they vary from 60 to 130 pages. if you have just a short manual, that suggests even more that you have a "special".

ignator · Jul 12, 2017

I just looked at my Huanyang manual, it has over 200 parameters (not all used).
P009 on mine is V/Hz ratio, if this is incorrect, you will get drive trips.

whateg0 · Jul 13, 2017

I can't get the scanner to fire up, so I'll have to do it at work tomorrow. But, the manual for my VFD sais Isacon Power Control Tech Co., Ltd, A131 Inverter, and appears to cover other models. Or, like the ad online, the manual could just be wrong. But, the settings seem to align with the VFD. Mine has 35 parameters, with the last four being info about the VFD. All told there are 26 pages, including the front and rear covers.

Here are photos of the parameters table.

2

713_4225.jpg - Google Drive

2

713_4157.jpg - Google Drive

JST · Jul 13, 2017

Isacon is one of the specials. A high speed spindle drive, IIRC.

whateg0 · Jul 13, 2017

Thanks for clarifying that. It's interesting how these products are marketed. I was wrong about the number of pages in the manual. It's 26 pages, but it only takes 12 sheets to print. Unfortunately, as a scan, it's still too big to attach.

rons · Jul 13, 2017

whateg0 said:
If I just wanted a single speed motor, I could have installed one of the several 2 hp single phase motors. The idea behind the VFD was to regain variable speed.

Lathe mechanical variable speed system is out? Is it expected back? Sounds like a perfect fit for a Huanyang VFD.

whateg0 · Jul 13, 2017

rons said:
Lathe mechanical variable speed system is out? Is it expected back? Sounds like a perfect fit for a Huanyang VFD.

The (older) Monarch 10ee used a variable speed DC motor and a backgear. There are no other mechanical means for varying the spindle speed.

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