VFD Questions and More

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unky_gumbi

Joined
Aug 28, 2009
Messages
7,951
So I got my Grinder in a Box kit today and I started looking into my next major purchase for the grinder, the VFD to run my 3 phase 1.5hp motor. I am looking at 115v input VFDs. I am leaning towards the KBAC-27D, but I stumbled across this one by Haunyang Electric
HY75XX500.jpg

specs are:
* Type: Single 3 phases
* Input: 100V~125V, 50Hz/60Hz
* Power: 1.5KW 14A, 2HP
* Frequency: 0.1~ 400.00HZ
* Accuracy: 0.1%
* Resolution: 0.01Hz
* Communication: RS485
* Display: 5 digit Digital Display for "V,A,Hz,Temp,Forward/Reversed,Fault"
I know a number of home machinist have bought them along with the companies air and water cooled spindles. I would say its not the quality of the KB unit, but the price is about half. I know my grinder is not the place to save money, but it is tempting:o.

My question is, is it save to run a 1.5hp motor on a VFD rated for 2 or more HP?

I will most likely buy my drive and contact wheels first to get everything lined up and the grinder actually built so I have time to research VFDs.

Next Question, does anyone here use USA Knife Maker? I mean in person not online. I am asking because I am thinking of making a trip that way and if they have a store front it would be a place I would want to stop at while in the area.
 
It is safe to run a motor of less HP then the drive. The drive is rated for it's max. HP.
Dan
 
Well I wasn't really worried about the VFD, I was more concerned about over powering the motor, but I think I get your drift. If I understand you correctly they will balance out as long as things are set and wired right.
 
unky_gumbi said:
My question is, is it save to run a 1.5hp motor on a VFD rated for 2 or more HP?

I will most likely buy my drive and contact wheels first to get everything lined up and the grinder actually built so I have time to research VFDs.

Next Question, does anyone here use USA Knife Maker? I mean in person not online. I am asking because I am thinking of making a trip that way and if they have a store front it would be a place I would want to stop at while in the area.
Click to expand...

Yes, rating is what it will handle, 1.5 in a 2 is safe.

Have you got a manual? Those ventilation slots look like it is unsealed and needs you to build a clean enclosure with cooling or heatsinks.

I used USA KM online and service was good.
In person, you may need to prearrange that with Tracy
(may save some shipping if you are there)
 
unky_gumbi said:
Well I wasn't really worried about the VFD, I was more concerned about over powering the motor, but I think I get your drift. If I understand you correctly they will balance out as long as things are set and wired right.
Click to expand...

Current is pull down, not push through.

The motor will draw what it needs, the larger vfd cannnot push too much to it.
 
I'd be concerned with the vents in the housing as well. I would definitly check if it is a sealed unit or not.
 
12345678910 said:
Yes, rating is what it will handle, 1.5 in a 2 is safe.

Have you got a manual? Those ventilation slots look like it is unsealed and needs you to build a clean enclosure with cooling or heatsinks.

I used USA KM online and service was good.
In person, you may need to prearrange that with Tracy
(may save some shipping if you are there)
Click to expand...

No I don't have a manual but it is available online. It is a made in China piece so the manual is a little tough to understand. A lot of the direct translation errors to make it fun. If I went the cheap way I would need to put it in a clean box. I still need to get all the numbers together and see what the real cost is compared to the KBAC-27D..

Saving a little shipping was the whole idea, I am only about an 8 hour drive from USA KM so if I was going to be in the area next month why not, and then there is always the in person impulse buys. I will give him a call as thr travel plans firm up.
 
The difference in price is the enclosure the KBAC-27D is NEMA 4 which means washdown and dust resistant. The drive you are showing looks to be IP20, if you mount it close to your grinder the metal dust may short it out. I just ordered the sixth one on this page http://www.wolfautomation.com/ProductList.aspx?CategoryID=823&ManufacturerID=361 for my 3HP KMG clone.

I just noticed if you go with a 220 input to the drive on the site list above is really reasonable.
 
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Yes it is a IP20 enclosure but is the enclosure really worth $150+.
I am kind of stuck to a few drives because I only have 110V available to me
 
You can buy a remote and mount the drive away from the grinder. I looked at a bunch of drives. To me it was worth the extra, my shop is not climate controlled as I understand the IP20 it is just made for impact. If funds are tight go with what you can get, mount it in a cabinet with vents and start grinding.

By the way 220 is pretty easy to get with a little research you could even do it yourself. Good luck.
 
I will be pretty much stuck mounting the drive to the grinder itself, sort of like this quick drawing because I don't have a permanent shop space to leave it set up on a bench. My shop is more less just my backyard.
grinder.jpg


My whole plan is to be able to lean it back and move it in and out of my storage shed/small garage, so unless I can get a dust proof case for the cheaper ones for a total price considerably less then a KBAC-27D it looks like I may be stuck spending the few extra dollars
 
I was able to find the KBAC-27D for around $340for a 2hp. I tell you if you are going to mount the drive like in the drawing you will need an enclosure, which will have to be larger with some type of air vents. If it was $100 or less I would go with a NEMA 4 drive.

Keep searching and don't get hung up on that KB drive, there are a bunch of drives out there. You will find one that has everything you need for a price you can afford.
 
The reason I keep going back to the KB drive is that it seems to be the most used drive out there, the majority of variable speed grinders I see are running KBAC-27D drives so it must mean something. I am still searching trying to find something that serves my needs at a more afordable price though
 
The NEMA drive can handle more heat as it has to perform in a closed (sealed) case. If you put a sealed case around the lesser unit, it can very well over heat.

So Yes, the NEMA 4 units "ARE" worth the extra cost.

MIke
Maker
The Loveless Connection Knives
 
unky_gumbi said:
The reason I keep going back to the KB drive is that it seems to be the most used drive out there, the majority of variable speed grinders I see are running KBAC-27D drives so it must mean something. I am still searching trying to find something that serves my needs at a more afordable price though
Click to expand...

I searched online and local sources to death without finding any bargains.

If it was much cheaper, either it was 220 input only, or an open case that would need extra work to create or buy a sealed enclosure with cooling.


If you really want to to build an enclosure, these are the cheapest I have found.
http://dealerselectric.com/item.asp?cID=28&PID=1109
 
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