Bader BIII conversion to variable speed -Help!

C

Chris Meyer

Joined
Aug 15, 2005
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Greetings, I need some help from the Gurus.
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I would like to switch my 1.5hp Bader BIII over to variable speed. I have been reading up on VFDs and it looks like the “2HP KBAC-27D controller (nema 4, closed) and a 2hp Leeson 56H motor (113026)” are the ticket, if you have a KMG grinder. I think that the KBAC-27D controller would work for me, but I don’t think the Leeson motor would fit my Bader.

I checked the motor on my Bader and it’s a Baldor model CL3513. It has a 56C frame, and a 5/8” diameter shaft that’s 1 7/8” long. The Leeson has a F56H frame. I have no idea if those frames are compatible, but since the numbers are different I’m assuming they’re not.

I checked Leeson’s website for a 2hp, 3 phase, 208-230/460 volt, TEFC motor but didn’t see any with the 56C frame.

Next I checked the Baldor site. I found a model VM3558 2hp, 3 phase, 208-230/460 volt, TEFC motor. It has the 56C frame, and the 5/8” diameter shaft that’s 1 7/8” long. I can purchase the Baldor motor from a place called Electric Motor Warehouse for $196.34. The KBAC-27D can apparently be had from State-Electric.com about $325.

I am fairly sure that this motor would fit my machine and would be comparable to the Leeson motor. However, I know next to nothing about any of this stuff. Therefore, I confess my ignorance and humbly ask all of you electrical/mechanical geniuses if the Baldor VM3558 motor would work with the KBAC-27D controller and, more importantly, if they would function properly on my Bader BIII? Thank you.
 
Converting to VFD is one of the best things you can do.
You are right to be careful about motor types. You will need a 'C-Face' framed motor. That means it needs to have that machined "face" (the part you see when looking at the motor straight down the shaft) with four threaded mounting lugs around it. You could use 56C. I'm using a 145TC-frame Baldor on my BIII. What's most important is that the motor has a C-face frame AND a mounting plate (the plate with holes on it welded to the bottom of the motor.
You will want to make sure you get a 2 hp, 3-phase, 220v motor. It can be 1750 or 3600 rpm or whatever, since the frames and bearings are the same regardless of RPM rating (at least on Baldor), and you'll be controlling speed with the VFD.
If it will save you money, you can get a larger shaft diameter and have the pulley bored and a keyway broached for just a few buck at a local job shop. (these operations should be no big deal).
If cost is a factor, I would definately troll through ebay for Baldor or Leeson, or whatever brand you prefer. You can often pick up these three-phase motors (sometimes brand new) for $100 or less.
 
When matching a VFD to a motor, it is helpful while shoping to know that your controller does not have to specifically say it's for single-phase input. If it says three phase input/three phase output, you can still use it with single phase input as long as you 'derate it.' That is: match it with a smaller motor than it's claimed capacity. A good rule of thumb is about 33.3 to 50% or greater. So if you're planning to use a 2 hp motor, your three-phase input controller should rated for 3 hp. (I prefer 5, if you can get it, but three should do.)
This tidbit can save you big money when looking into surplus units.
 
Chris

The 3-phase motors and VFD's are designed to be sold as interchangeable commodities. With motors rated for a few hp, you will be OK as long as you select a VFD with a voltage rating that will accomodate the voltage rating of your motor and has a current, kw or hp rating that is at least a bit higher than that of the motor. There is no need to do anything like match brands. Do make sure that your motor is "inverter rated" or it may lead a short life.

JCaswell is correct about having to derate the VFD to 57% of it's nominal rating if it is set up for a 3-phase input and does not claim to be able to give full output power without derating when using a single-phase source.

Phil
 
Guys, I apologize for being obtuse but the generalized information on VFDs and motors, while greatly appreciated, is still over my head. I don't understand electronics well enough to figure out for myself whether a Baldor VM3558 motor would work well with the KBAC-27D VFD, nor whether this specific combination would work on my Bader BIII. My question remains, if I purchase the VM3558 motor and the KBAC-27D controller (and hook them up correctly) will they work to convert my Bader BIII to variable speed?

I really need someone to lead me by the hand on this one. My original post had links to most of the components, but I can dig up additional information if necessary. Someone would just have to tell me what to look for. Thanks again and sorry for being so ignorant of the subject.

The specs on the Baldor VM3558 motor are;
Baldor VM3558 Motor
Catalog Number: VM3558
Specification Number: 35A13-872
Horsepower: 2
Voltage: 208-230/460
Hertz: 60
Phase: 3
Full Load Amps: 6.5-6.2/3.1
Usable at 208 Volts: 6.5
RPM: 1725
Frame Size: 56C
Service Factor: 1.15
Rating: 40C AMB-CONT
Locked Rotor Code: K
NEMA Design Code: B
Insulation Class: B
Full Load Efficiency: 82.5
Power Factor: 77
Enclosure: TEFC
Baldor Type: 3528M
DE Bearing: 6205
ODE Bearing: 6203
Electrical Specification Number: 35WG0872
Mechanical Specification Number: 35A013
Base: N
Mounting: F1
​


The description of the KBAC-27D controller says;

The KBAC-27D controller is an Adjustable Frequency Drive housed in a NEMA-4X / IP-65 wash-down watertight enclosure. It is designed to operate 208 - 230 Volts, 3-phase, AC induction motors through 5.6 Amps RMS on 115 VAC 50/60 Hz or 6.7 Amps RMS on 230 VAC 50/60 Hz using standard single phase input. Standard features of the KBAC-27D include, I2t Motor Overload Protection, Short Circuit Protection, Power Start delivers over 200% starting motor torque, Output Fault Relay. There are eight adjustable trimpots including: RMS Current Limit, Slip Compensation which provides excellent load regulation, Linear Acceleration and Deceleration make the drive suitable for soft-start applications and JOG. Standard front panel features of the KBAC-27D include diagnostic LEDs, a Start/Stop Switch, and a Main Speed Potentiometer and a power on/off switch. Optional accessories for the KBAC27D include a forward/stop/ reverse selector switch.​


The motor currently on my BIII is a Baldor model CL3513 with a 56C mount. The specs on this motor are;
Catalog Number: CL3513
Specification Number: 35T946-0199
Horsepower: 1.5
Voltage: 115/230
Hertz: 60
Phase: 1
Full Load Amps: 15/7.5
Usable at 208 Volts: 7.9
RPM: 3450
Frame Size: 56C
Service Factor: 1.15
Rating: 40C AMB-CONT
Locked Rotor Code: H
NEMA Design Code: L
Insulation Class: B
Full Load Efficiency: 70
Power Factor: 82
Enclosure: TEFC
Baldor Type: 3528L
DE Bearing: 6205
ODE Bearing: 6203
Electrical Specification Number: 35WG0199
Mechanical Specification Number: 35T946
Base: RG
Mounting: F1​
 
This controller should work with that motor. I think the key phrase in the controller description is:
"AC induction motors through 5.6 Amps RMS on 115 VAC 50/60 Hz or 6.7 Amps RMS on 230 VAC 50/60 Hz using standard single phase input."
If it didn't specifically say "using single-phase input," I'd say no, it's too small because of the derating discussed earlier.

Assuming this description is accurate you should be in fine shape.
Always, always get a manual with these VFDs. It is helpful when buying your first one to pay a tad more and get it from somone that can support the product. By this I mean: someone that you can call when you're stumped and they can (and will) walk you through something. If you buy the controller on ebay, it's just you and the manual. That's usually enough, but for the first one, if you're tenuous about it, don't be a cheapscate. Get it from someone with customer service.


JUST MAKE SURE THIS MOTOR HAS A MOUNTING BASE (THAT WELDED PLATE ON THE MOTOR WITH THE HOLES FOR MOUNTING TO A WORKBENCH)!!!!!! I NOTICE THAT THE SPECS DIFFER FROM YOUR EXISTING MOTOR SO IT PROBABLY HAS NO PLATE. Just find the same motor with the same base and mounting specs. I'd call the retailer and be sure they physically affirm that plate is on that motor!
 
I believe that's the same NEMA 4 that Rob Frink from www.beaumontmetalworks.com sells.

I got two of those drives from Rob but sourced my own motors. The Penta Power VFDs have no problem running my 1.5 hp and 2 hp Leeson motors on my KMGs. You might be able to save a couple dollars shopping elsewhere, but if you buy from Rob you'll get an unexpected level of support. Even before I bough my VFDs from Rob, he helped me sort out the wiring on a Toshiba VFD that I started with! It blew up because it was NEMA 1 and got filled with steel dust and shorted out. When I ordered my KB VFDs from Rob, he said something about including a couple things he thought I'd need. I paid little attention until the drives arrived. It was then I found he'd included several top notch wash down rated fittings as well as a length of just the right wire to connect the drive to my motor and totally seal the connections from metal dust. He also included a mains power disconnect switch that's an optional KB part that other resellers want real money for. I got more than I thought I paid for.

I can say for sure that these drives will work just fine into the right 1.5 or 2hp motor driven from single phase home 208-230V. A VFD is a little hard on motors. All the Leeson motors Rob sells are VFD rated.

Looks like he's even put together a nice variable speed package for the Bader recently. Look here then click on the Bader Variable Speed Conversions link.

http://beaumontmetalworks.com/

I saw a post earlier where someone had suggested a 1725 or 3450 motor as suitable. As I understand the Bader, it's direct drive design with the drive wheel attached directly to the motor shaft, unlike the KMG which is driven by a V belt. If that's the case, only one of those motors will likely give you the right range of belt speeds with the VFD. It looks like the package Rob has uses a 3450 RPM motor. I'd be willing to bet that a 1825 motor on a Bader might givee you some very fine speed control at low speeds but probably would not include hoggin!

I remember when I was going through setting up my drives and arranging all teh parts, Rob recommended that on my KMG with a 3450 rpm motor, that I should use equal sized pulleys yielding a 1 to 1 drive ratio at that RPM range. On my other machine with a 1725 RPM motor he recommended a larger pulley on teh motor and a smaller pulley on the drive wheel axle yielding basically a 2 to 1 drive ratio, increasing the speed of the drive wheel axle to 3450 rpm.

Give Rob call, he'll hook you up and then stand behind what he sells you.
 
J Macdonald is right about the value of specialized service in this case. Sounds like Rob would be a great help.

Regarding the use of a 1750 (or so) motor vs. a 3600 rpm motor, I use either on my many VFD-controlled machines and get 3600 rpm out of both. Back when I was receiving specialized help with VFDs, I was assured you could use either. If using the slower motor, you just run the VFD from 0-120 hz instead of 0-60 hz. It's usually a standard preset option when setting up the VFD.
I was further assured by folks at Baldor that this poses no problem to comparable motors with different posted speed ranges since the bearings and all are the same between the models. I figure if the factory guys say it's OK, you're probably pretty safe. I've een using them this way for years now without trouble.
 
Thanks guys, that's the info I needed. I did see the setup that Beaumont Metal Works, Ltd. is offering and I'm sure it's a good deal, but I just don't have that much money to spend at the moment. I'll check on that mounting plate and rethink the change from 3450 rpm to 1725 rpm. I can change the drive wheel but I think I'll call Dan Johnson at Bader and ask him what he suggests. Thanks again.
 
Changing the size of the drive wheel enough to make up for the rpm difference wil mean that without other significant changes, your belts won't fit anymore.
 
Chris Meyer said:
I'll check on that mounting plate and rethink the change from 3450 rpm to 1725 rpm. I can change the drive wheel but I think I'll call Dan Johnson at Bader and ask him what he suggests. Thanks again.
Click to expand...

My point was that you could use either speed. If a 3450 motor is convenient, go with that. They're sometimes hard to find second hand, though, thus the 1725 option.
If you do run the 1725 and set up your controller to operate between 0 and 120 hz, you won't need to change the drive wheel. The motor will simply go faster. You may want to change the drive wheel to achieve a higher SFPM range after you talk with the guys at Bader. I have a pretty big drive wheel now and that baby can really book!
If you do go with a larger drive wheel (within the range of sizes suggested by Bader), you will find that the Bader's tracking-system movement is enough to accomodate the change without worrying about about belt size and such, though I suppose it very well could be a problem on differnt grinders as J. Mac. suggests.
 
Chris, There is alot of good info posted here...some is relevant and some may add to your confusion. Here are my thoughts.

Your Bader is designed to run with a driveshaft speed of 3450 rpm. So you should use a 3450 rpm motor. I would not use that Baldor motor listed. Also, just becuase the motor frame is a 56C doesn't mean that it has a base mount as well...you need to double check because you will need both. The Baldor info is not clear on this.

The KB drives are rated for their full nameplate values. They are not derated as some, but not all other VFD's. The KB drive is an enormous unit with a very high duty cycle. Along with it's convinient manual controls and wash-down enclosure make it the best unit for our belt grinders in my opinion. The KB unit has a 2X speed selection which will allow to you run a 1725 rpm motor at 3450...but this is not recommended. The drive outputs constant torque up to the motor base speed (60 hz) then at higher speeds, it outputs constant HP. The result is that as the speed increases above the base speed, the motor torque diminishes linearly. Running the motor above 60 hz will give you a broader speed range at the trade off of lower torque. For our belt grinders, we need the most torque at the highest speed when hogging.

If it were me, I would use a 3450 rpm motor on my Bader with the KB 27D drive. Any high quality industrial motor will do...but VFD compliant motors would be better due to their superior winding insulation to minimize harmonic noise and mag flux leakage.


I'm not sure if this makes any sense...or if it just adds to your confusion. I can't say enough positive things about these KB drives. You should also buy the optional power on/off switch.


Good luck and have fun with your project!

Sincerely,
Rob
 
Why not call the people at Bader and ask what you need for the conversion? I am sure that they stock and sell the necessary parts. I just bought a BIII from them directly and they are great people to deal with. My machine was damaged in shipping. The damage to the machine was subtle and not immediatley noticable. Even though the shipping company (UPS) is likely not going to take responsibility, the people at Bader never even flinched and have absolutley bent over backwards to make it right. Just FYI - I had mine equipped with the 2 HP VS motor and love it.
 
The guys in the motor design group here at work told me that the reason to use an inverter rated motor is that the electrical insulation used in the motor is chosen to withstand high voltage peaks that the VFD will apply to the motor. If the motor is not inverter rated, the insulation in it may break down after some period of used, causing a failure of the motor.

If you are going to the trouble and expense of buying a sealed VFD like the ones KB, you really should use the sealing glands/fittings on all the wires and cables going in and out of the VFD enclosure. Otherwise, the conductive steel dust will still get into the enclosure and cause the VFD to short out. Rob Frink may be able to supply them to you. If not, I can find out where the company I work for buys them from.

Phil
 
Rob certainly know his stuff and I would generally defer to his advice.
The boys at Bader do a lot of VFD work and are very helpful too.

It is true that you technically lose torque running the slower motors faster, but in my experince running a 2 hp 1725 motor on a BIII with 14 inch contact wheel ... I can lean on that baby as hard as I can with a 36-grit belt and it won't even slow down. I also run a similar set up on a band saw (running pretty slow for ti and really fast for wood) and I've never had torque issues or burnt motors.
Of course, having said that I'll probably go right out and char a motor for the first time in 10 years ...
 
Guys, thank you very much for the information, and especially for making it understandable!

Fixed Blade Fever, if you don't mind me asking, what motor did Dan equip your variable speed BIII with?

Also, I noticed that Bader sells their variable speed BIIIs with a "with Nema 12 control". Just for my edjumacation, what are the basic differences between Nema 4 and Nema 12 enclosures?
 
Chris,

It is a baldor 2 hp TEFC, 2500 RPM motor. It has a 145TC Frame Number and a Type Number of PN3536P.

Let me know if you need any other info.

Thanks

Brad
 
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