Recommendation? Why the KBAC-27D VFD?

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Jan 16, 2013
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Hi, all!

I'm making my own 2x72 belt grinder and having been doing lots of research on motors and vfds. I have found the motor that will work with my setup, but am looking into VFDs now. It seems that the only VFD I see people in the knife community talk about is the KBAC-27D. Why do people chose that particular VFD? I know there are more options. I work in a steel fabrication shop and we have VFDs on some of our equipment. I think the GS2 VFD comes to mind for what we have. Anyways, why the 27D and not other VFDs that are on the market?

Thanks in advance.
 
I don't understand the emphasis on KD products either. I worked in industrial maintenance and never saw a KD product in 20+ years. I have only heard good things about them, just never saw them in a factory setting. I have VFDs from Leeson, TECO, and Siemens all of which work fine. All of these have NEMA 1 enclosures and may have issues with metal dust if not properly mounted and protected.
the old sailor
 
In a factory environment, electrical enclosures are common. It's not a problem to put an unsealed drive in a sealed electrical enclosure and to put a set of sealed controls where the operator can get at them. In really dirty/wet environments, the enclosure is often a separate room.

In a home shop, you can put an unsealed drive in a sealed enclosure and provide it with control switches and a speed control potentiometer yourself. I have done it several times.

For a bladesmith, rather than an electrician, the cost of buying a sealed KBAC drive with switches is more-or-less comparable with the cost of buying an unsealed drive, an enclosure, the switches/potentiometer and all the gubbins needed to connect it all together. Then there's the time needed to actually do it and, for many, the time needed to research the process of doing it. Once built, it will take up a lot more space (usually precious bench space) than a factory-sealed VFD because the enclosure will be bigger.

The KBAC drives are configured by setting a series of potentiometers, jumpers and multi-position switches, rather than the menu-driven digital interface used by almost every other drive. The KBAC may be seen as having a friendlier interface by those who tend to "think analog". It's a poor way of expressing things, for which I apologize, but some of us just feel more at home with analog stuff. I suspect that the majority makers-of-things have a largely analog view of the world.

Most of the other NEMA4/IP66 sealed drives are conventional drives (menu-driven setup) with beefed-up, sealed enclosures.

In essence, the KBAC drives are reasonably-priced, compact and well-targeted at the market that includes this forum.

For anyone in Europe reading this, Invertek drives tend to be the preferred sealed drives (IP66) for grinders over here. They are menu-driven, but it's a relatively user-friendly menu.
 
Hi, all!

I'm making my own 2x72 belt grinder and having been doing lots of research on motors and vfds. I have found the motor that will work with my setup, but am looking into VFDs now. It seems that the only VFD I see people in the knife community talk about is the KBAC-27D. Why do people chose that particular VFD? I know there are more options. I work in a steel fabrication shop and we have VFDs on some of our equipment. I think the GS2 VFD comes to mind for what we have. Anyways, why the 27D and not other VFDs that are on the market?

Thanks in advance.
If you choose a 1 or 1.5 hp motor, a KBAC-27D will work fine with standard 115 vac house current. So will other brands. If you wish to run a motor greater than 1.5 hp, I recommend a VFD that connects to a 240vac outlet(like your electric range or electric clothes dryer). Download the VFD manual before you buy and follow the manufacturer's recommendation on wire size.
Myself and many others have found that by locating your VFD behind, above, and to the side of the motor you should not have dust issues. You can make a adequate filter using furnace filter material you can buy at hardware store if you need too. If you wish, you can buy other brands that are NEMA 4(dustproof, waterproof) rated for about $75 more than NEMA 1 (not dustproof).
If you can program a cell phone, you should have no issues programming a VFD. If you have an equipment maintenance man at work, he should be able to help you with any issues.
It is handy to use plugs and receptacles between the VFD and the motor so you can run different 3 phase motors with the same VFD. I use the same VFD to run my belt sander and my disc sander.
I hope this answers your questions.
the old sailor AT1 USN(Ret.)
 
I use three KBAC 27-d ( one is a model number for my 1 hp disc grinder) drives and they have been totally reliable for several years now and easy to hook up and use. When I bought my first one it was around $600 but the last 27-D I bought was closer to $375. I have seen many forum members use another less expensive and popular VFD which they usually build enclosures for because they need to be dust proof and at least water resistant but I will buy KBAC products from now on because I trust the quality and reliability and always try to spend a little more on equipment that is so important. Most of the really good knife makers that I know use the best equipment they can afford. You don't have to use the best equipment to make really good knives but it sure helps in the long run to have the best equipment you can afford in my opinion. Larry
 
Because it's what came with my Pheer grinder ..... ¯\_(ツ)_/¯
 
The enclosure is the biggest draw for me. Other than that, they're relatively simplified and straightforward as far as VFDs go. No need to scroll through dozens of parameters. Just check a couple of pots and jumpers, hook up a few wires, and you're ready to go. The dual voltage capability is nice as well, and something that few others offer (surprisingly).
 
So, this got me thinking about my Tru Grit disc grinder that came with a KBMA-24D in a NEMA 1 enclosure. I comes mounted directly above the motor. Do I need to rethink this? There aren't any open ports on it that I can see.
 
NEMA 1 seems to cover a pretty broad range: too broad to be helpful in this case. The IP rating is probably more useful here.

http://www.dsmt.com/resources/ip-rating-chart/

The IP rating for the KBMA range is IP50. The first digit is protection against solids and the second digit is protection against liquids. IP50 is protected against dust but not protected against liquids at all.

With a little care, you should be fine.

NEMA 1 also seems to include IP20, which is protected against solid objects 10mm and larger (effectively a standard finger), completely unprotected against liquids. Most "normal" industrial VFDs are IP20.

http://acim.nidec.com/drives/kbelectronics/products/ac-drives/ac-drives-nema-1
 
I have the KBAC-27D it's probably overkill, but I rather be safe than sorry. I'm more worried about humidity and condensation in my shop than dust.
 
So, this got me thinking about my Tru Grit disc grinder that came with a KBMA-24D in a NEMA 1 enclosure. I comes mounted directly above the motor. Do I need to rethink this? There aren't any open ports on it that I can see.

The KBMA-24D on the TG disc has been in service for many years with no issues.
 
NEMA 1 seems to cover a pretty broad range: too broad to be helpful in this case. The IP rating is probably more useful here.

http://www.dsmt.com/resources/ip-rating-chart/

The IP rating for the KBMA range is IP50. The first digit is protection against solids and the second digit is protection against liquids. IP50 is protected against dust but not protected against liquids at all.

With a little care, you should be fine.

NEMA 1 also seems to include IP20, which is protected against solid objects 10mm and larger (effectively a standard finger), completely unprotected against liquids. Most "normal" industrial VFDs are IP20.

http://acim.nidec.com/drives/kbelectronics/products/ac-drives/ac-drives-nema-1
That's helpful info. Thanks!
 
Tech support is good with KB. I had some issues with a used Burr King and they fixed me right up, pretty decent on the $ as well.
 
I've read the manual several times.


I've only ever used a 1.5 because that's what the manual says.

However others including Travis Wuertz have tried the 110 on a 2 hp motor and say it works.

A belt grinder is probably not pulling full 2 hp load

I have my KBAC-27D on 110 right now with a 2HP rated Leeson, it's supposedly running at 1.5HP. I have a 220 cord ready to go once I'm able to get a new outlet and breaker set up, though it's working just fine now so I'm not in a real hurry either.
 
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