How To Motor/VFD Help

G

GreyRider1917

Joined
Jul 31, 2019
Messages
10
Hello all. I am fairly new to knife making and I just built a DIY 2x72 grinder. I was initially using a 2.25 HP treadmill motor directly attached to a 4" drive wheel. Worked great for a couple of weeks till it literally caught on fire and was spitting out flames. So I just bought a brand new Baldor Reliance 2HP 3 phase motor. 1800rpm 60hz 230v.

I hooked up the motor and installed the 4" drive wheel directly to it. I hooked it up to my 1.5kw VFD that I use for my cnc router and changed all the settings I could figure out. The motor spins but once I put any pressure on the belt it bogs down and even when I let off the belt it still runs slow. So I thought it might be the vfd. It was an old cheap chinese vfd.
So I just got a new 2.2kw vfd delivered today and it has alot more settings to change. So i put in all the motor information and tried it out.

Same thing. Bogs down with almost any pressure on the belt.

Do I have to edit these torque boost settings? This is getting frustrating. I bought this big expensive motor thinking it would be great. I hope its my vfd settings and this thing actually performs just as good if not better than my crappy old treadmill motor.

Thanks for any advice.

Charlie
 
To help very much at all we need a bit of info about the VFD - which did you get? A link to the manual would be VERY helpful. Those "cheap" Chinese VFDs tend to work just as well as any VFD does, other than the NEMA 1 enclosure that needs a good filter over the air inlets.

I'm sure you checked the freq of the motor on the CNC router - that could well be at 400 hz while your new motor will be 60 hz..... wait, that depends on what part of the world you're in. Could well be 50 hz rather than 60 hz. Perhaps it would help also if you filled out your profile with location and a bit about yourself?

Ken H>
 
Hey sorry, it is a chinese vfd but has much more cutomizeable settings than my last one. It is a LAPOND SVD-ES but the manual says Soyan Power SVD-E.
Yes the spindle is 400hz and the new motor is 60hz. I changed that setting on the new vfd. I am located in the USA.

The motor tag specs are:
HP-2
Volts- 208-230/460 I have it wired for low voltage.
Amps- 6.5-6.2 / 3.1
RPM- 1725
Frame 56C
HZ- 60
Phase-3
SER F 1.15
Code- K
Des- B
Class - B
TEFC


Ken H> said:
To help very much at all we need a bit of info about the VFD - which did you get? A link to the manual would be VERY helpful. Those "cheap" Chinese VFDs tend to work just as well as any VFD does, other than the NEMA 1 enclosure that needs a good filter over the air inlets.

I'm sure you checked the freq of the motor on the CNC router - that could well be at 400 hz while your new motor will be 60 hz..... wait, that depends on what part of the world you're in. Could well be 50 hz rather than 60 hz. Perhaps it would help also if you filled out your profile with location and a bit about yourself?

Ken H>
Click to expand...
 
kylemiller said:
What parameters have you entered?
Click to expand...
I moved the torque boost to 10 percent. Any lower it boggs down even faster
torque boost cut off frequency i set to 50 but as i am reading it right now i thought that was hertz but it is actually the percentage of frequency rating of motor. So as i have it the boost cutoff is 30 hertz which may be my problem.
min freq - 0
max freq - 60
amps 6.2 but for some reason after i run it the setting goes down to like 3.5
volts 230
speed 1725....after running goes to 1400.
Motor Type section is set to G type. there is also P-type. NO idea what this means.
Rated motor- 1.5kw
 
Well the torque boost percentage wasnt it. Just tried all different settings and it didnt change. Now when i just tap a blade on the belt it slows down. And the motor is getting hot. Also if i let it run with just the belt for like 20 seconds it will slow down on its own. No idea what the heck is going on.
 
Nevermind, Im an idiot. I read the wiring diagram wrong on the motor plate for low voltage. All good now. Doesnt bog down but not as fast as i hoped with that 4" drive wheel. Im going to have to get a larger drive wheel. Thanks for helping and listening. I am glad I found bladeforums and am excited to be a part of the group.
 
I doubt you'll notice much of anything with torque boost settings one way or the other on a 2HP motor with average grinding practices. I'd just leave them at default for now.

As for being too slow with a 4" wheel, you'll likely want to increase your max frequency to AT LEAST 120Hz. A lot of us are double speeding our 1800 RPM motors to 3600 RPM, especially if using a 4" wheel. Actually, your VFD will probably generate up to 400Hz, which on an 1800RPM motor will give you about 12000 RPMs. IIRC, the average set of decent 56 frame motor bearings can take up to about 15000 RPMs or better, although at that point your concern will more likely be vibration than heat, depending on how balanced your machine is. You could probably take it up to at least 200-240Hz without too much concern, although most makers are grinding at a fraction of that SFPM most of the time anyhow.

If you ramp up the Hz to get more speed, just be sure to double check for excess vibration anywhere, and excess heat (which is usually less of a problem because your motor fan is actually turning faster and cooling MORE.) It's actually the lower speeds that end up overheating windings and such, though there are other things like your grinder's wheel bearings to also consider when you start spinning everything at higher RPMs.
 
I was going to suggest you go back and look at the motor wiring. Your description sounded like it was wired to the wrong terminals. Glad you found the problem before the smoke started.
 
Great thanks everyone. Yeah I was afraid to run the motor over 60hz. I will slowly bring it up to see how it works at faster speeds.

For some reason my VFD keeps changing some settings back on its own. Mainly the motor rpm and motor amps. I set the rpm to 1725 but when I check it after I run the motor it goes to 1400rpm on its own.

Same with the amps. I put in 6.2 and it changes itself back to like 3.5. Not sure if that makes a difference but just found it weird.
 
The motor should run fine up to 120 Hz.

Don't worry about setting every parameter manually. Use the "Reset to factory"instructions for setting the VFD back to default and it should be fine. If you need to change something after that, then do it judiciously. 120Hz max and 30 Hz min are about all you will need to set on most units.
 
Andrew hit the nail on the head - set hz to 120 (or even 130) to run motor up to 3600 to 3800 rpm. With 1800 rpm you're only getting around 2,000 SFPM which is pretty slow for heavy grinding. The 4" drive wheel will give you slightly more SFPM than the rpm. Just be sure the motor RPM is set to 60 hz rather than what sometimes is a default of 400 hz on Chinese VFDs.

Interesting it keeps changing some of the parameters after running - are you SURE you got them saved before exiting programming mode?
 
The resetting parameters sounds kind of odd. I know some VFDs have an "auto tune" function, but I think you have to be pretty deliberate in setting that up. It sounds like maybe your parameters aren't actually being "set" or "saved" after you change them? Most VFDs will require an additional key press after you input a different variable. I think on mine you have to hit "set". Some have a "str" (store) key. Others may have an "ok" or and "enter" key.

It's also possible that you have to change a specific "edit" parameter before you can even make changes to other parameters. Most VFDs will make it pretty obvious if your parameters are locked out or require a pass code, but I'm not familiar with your specific model.
 
Thanks everyone. Ok I will change the max min hz settings. I have to hit set after I change a setting and every other setting is staying where I put it except rpm and amps.

I’m just gonna leave everything as default except the motor data from the plate.

Thanks again
 
Default frequency seems to be 50 Hz, which would explain a lot if you are not saving the changes.

I would go through the PB settings PB01 to PB06 and set them to the values on your motor rating plate, then cycle through them again and see if they have saved: that is to say, when you cycle through the settings, they show the values you entered. If they do not, walk away. Do whatever you need to do to clear your head: go fishing, drink beer, chase women. Whatever it takes. Come back relaxed and read the manual. There is a good chance you'll have missed something fairly obvious and you'll cuss yourself for a fool, but get it right this time (this is from personal experience). If you have looked at it with fresh eyes and still can't get the settings to stick, it might be helpful to get someone else to take a look. Teenage kids are occasionally useful.

If the values you entered are sticking, check that parameter PB00 is set to zero (no autotune), go to parameter 13 (maximum frequency) and set it to 120 Hz. Check it has stuck. It is also worth checking that P0.00 is set to 1 (V/Hz).

Give it a try and see what happens.

If I've read the manual correctly (it is not a great manual, I found it at http://www.soyan-tech.com/uploads/20189675/PDF/SVD-e-User-Manual.pdf ), this should work and give you something in the region of 3500 motor RPM at maximum.

If it works, go through the entire parameter list and note down all the values before you power down the drive. Power down the drive, wait an hour or so and power it back up. Check the parameters are still whatever they were before powering down.

Try running again.

Let us know how it goes.

If it works and you are feeling adventurous, you might then want to try autotuning the motor and running in Sensorless Vector mode.
 
You must log in or register to reply here.
Back
Top