Electric motor and VFD questions.

R

Randydb

Joined
Sep 27, 2014
Messages
1,107
Hi,
I am beginning to collect the parts to make my own grinder. I always thought I would just use step pulleys, but I am starting to think maybe I should start watching for vfd possiblities.

I have only read a bit about vfd's and I realize that they won't work on certain motors. I have it in my mind that they won't work on 110v units? Am I right? BUt if I can wire up for 220 then a vfd will work. They can be used on single or 3 phase power but they are specific to the phase right?

So I spotted a 1.5 hp Delta motor for $60. Looks like it is in quite new and nice shape.

But they haven't posted a pic of the spec plate. This is all the info I have.

HP 1.5
RPM 3450
V 115/230
A 7.5/15
Hz 60
Runs quiet and smooth.

I still need to know if it is single or 3 phase? What else do I need to know?
I have asked them to send me a picture of the plate so I can get the rest of the info.
Any help here would be appreciated. I kind of think $60 is a great price.

Randy
 
To run a variable speed VFD set-up you will need a 3-phase motor. 3-phase motors only come in 220 volt. Many VFDs will allow you to run a 3 phase motor using either 110 or 220 volt. The KBAC 27 D will run a 2 HP motor on 110 Volt but you will only get 1.5 HP. If you can run 220 to the VFD you will be able to get a full 2 HP from the motor. You will want a 1750 motor instead of 3450. The VFD will allow you to run the motor at 2x speed. My KBAC 24D that I have on my disc grinder runs a 1HP motor off of 110v power. It works great.

So you do not NEED 220v in the shop, but you will need the correct VFD and a 3 Phase 220v motor. This is a link to the 27D drive.
http://www.electricmotorwholesale.com/9520-KBAC-27D/
 
You need to know if it's a TEFC (Totally Enclosed Fan Cooled) or an open frame, and if it's a 3 ph motor. "IF" 3 ph I suspect it will be a TEFC.
 
I went for the kbda-24d and got a 3ph 1 hp 1800 rpm motor, very easy to wire and set up check out 2x72beltgrinder.com he has very good instructions on wiring that I used and worked like a charm. For the kbda-24 there are jumpers on the panel you can move to switch it from 220v to 110v, also there's a few good videos on YouTube about wiring etc. I'm on my phone so I don't have any links just search wiring vfd to motor or something to that effect
Bear in mind I did this for a disc grinder so your mileage may vary
Also for me to say it's easy to wire means it's pretty easy, I didn't know much about this type of thing before I started but it helps if your handy and watch some YouTube
 
Okay, I am getting this. Need 3 ph 220v motor, but some vfd can run 110 or 220 in the shop and it should be TEFC.

I live in a regular city house. My buddy who is a farmer tells me you don't get 3 ph power in houses. Just industrial settings/buildings. He isn't an electrician. Is he wrong? I would love it if he was! :D Can I get an outlet wired in my garage that has 3ph power to it?

Thanks
Randy
 
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I will cross the wiring stuff up bridge when I get there Williamph . My daughter's boyfriend is in construction and could probably do it or would have a contact for me.

j Hoffman mentions I need 1750 rpm instead of 3450 because I can run it 2x with vfd. So I this Delta won't work then because it is 3450?
 
I am an electrician and I doubt it very much that you have 3 ph power in your house. However, you still have options. If you pay a bit more, you can get a 1 phase 220v drive that will produce 3 phase output. I installed one on a saw for a guy a few months ago. I think he paid around $1000 CDN for it new. Other option is to get a phase converter and 3 phase drive. I have installed and worked on these set ups before but am unsure about prices.
Hope this helps
 
Randy, 3450 vs 1725 rpm has been tossed around a good bit with some folks coming down solid in the 1725 rpm camp, others find 3450 rpm best. Either one will work, just what you can get at best price..... this is with use of a VFD only.

I went with 3450 rpm because new price of a 2 hp 3 ph motor was $127 shipped (and still is) while the 1725 rpm is $168 shipped (if I remember correctly). Using the double speed run will allow either motor to run at 3500 to 4,000 rpm just fine and you'll never know the difference. The difference is the 3450 rpm motor will have a tad less torque at lower speeds than would the 1725 rpm motor. You don't use much torque anyway at low rpm, but at max rpm is where you'll use most of your torque, and there the 1725 will have a very small amount less torque than does the 3450 rpm motor. In the real world, you'll never know the difference, so get the one that is the best price.

The 3450 rpm has 2 poles while the 1725 has 4 poles - that's why the 1725 costs more, and also weighs a few lb more.

You don't have 3 ph in your house I'm pretty sure, but that's no problem. If you read a bit, VFD's will take 120vac or 220 vac single phase and convert it to 3 ph 220 vac just fine. 120 vac works to convert to 220vac 3 ph just fine for motors of less than 2hp. 2 hp is pushing a bit, and I'd prefer to use 220vac 1 ph to convert to 220 vac 3 ph for 2 hp and above.

Me being a cheapskate I went with a chinese VFD for $120 shipped, but it's an open frame rather than NEMA 4X dust proof. For full time 10/day, 5 day/wk use I'd go with a NEMA 4X enclosure for VFD, but for my hobby work I put air filter over inlets and have VFD mounted to back & one side of grinder and dust hasn't been a problem. OR - mount in a dust proof box.

Later
 
$1,000 CND for a VFD? That must have been a big motor! The usual price here in USA is around $120 shipped for a 2-3hp VFD (open frame) or around $300-400 for a 2 hp NEMA 4X "good" VFD.
 
Grenfells I think you are missing the point of using a 3 phase motor. He does not need 3 phase current to run a 3 phase motor on a grinder ..... if you plug a VFD into a single phase outlet then hook a 3 phase motor to it you will have a variable speed power source.

Your farmer friend is right , you dont have 3 phase in your house BUT you could wire a receptacle from the output side of the vfd and that outlet would be 3 phase
 
The motor the $1k VFD got hooked up to was only 4hp. The VFD could do a lot of things actually way more than the guy needed or you would need for a grinder.
Spalted, sorry if it didn't come out right I was essentially trying to say the exact same thing you just did.
 
Okay I got reading on this thread which is happening simultaneously.

http://www.bladeforums.com/forums/s...y-This-is-my-question?p=16115612#post16115612

I have tracked down this motor for $127
http://www.automationdirect.com/adc...-Phase_Motors,_56C_(0.33_-_2HP)/MTR-002-3BD36

Now I am wanting to find a VFD drive for it...I see these on ebay

http://www.ebay.com/itm/1-5KW-2hp-7...386082?hash=item541689dae2:g:XJ8AAOSw0vBUkjm0

Is it going to work with this motor?

Is there anything else I would need?
 
Randydb said:
Okay I got reading on this thread which is happening simultaneously.

http://www.bladeforums.com/forums/s...y-This-is-my-question?p=16115612#post16115612

I have tracked down this motor for $127
http://www.automationdirect.com/adc...-Phase_Motors,_56C_(0.33_-_2HP)/MTR-002-3BD36

Now I am wanting to find a VFD drive for it...I see these on ebay

http://www.ebay.com/itm/1-5KW-2hp-7...386082?hash=item541689dae2:g:XJ8AAOSw0vBUkjm0

Is it going to work with this motor?

Is there anything else I would need?
Click to expand...

Yes....that motor will work with that VFD. You'll need a 220V outlet to plug the VFD into, and then of course wiring between the VFD and the motor.
 
Randydb said:
Okay I got reading on this thread which is happening simultaneously.

http://www.bladeforums.com/forums/s...y-This-is-my-question?p=16115612#post16115612

I have tracked down this motor for $127
http://www.automationdirect.com/adc...-Phase_Motors,_56C_(0.33_-_2HP)/MTR-002-3BD36

Now I am wanting to find a VFD drive for it...I see these on ebay

http://www.ebay.com/itm/1-5KW-2hp-7...386082?hash=item541689dae2:g:XJ8AAOSw0vBUkjm0

Is it going to work with this motor?

Is there anything else I would need?
Click to expand...

You are better off with a slower motor. Look for a 1700 Rpm. The VFD will also need an enclosure that will keep dust out, but also allow it to cool. That is one reason so many makers spend the extra money on the KBAC
 
Randydb said:
Okay I got reading on this thread which is happening simultaneously.

http://www.bladeforums.com/forums/s...y-This-is-my-question?p=16115612#post16115612

I have tracked down this motor for $127
http://www.automationdirect.com/adc...-Phase_Motors,_56C_(0.33_-_2HP)/MTR-002-3BD36

Now I am wanting to find a VFD drive for it...I see these on ebay

http://www.ebay.com/itm/1-5KW-2hp-7...386082?hash=item541689dae2:g:XJ8AAOSw0vBUkjm0

Is it going to work with this motor?

Is there anything else I would need?
Click to expand...

You need the manual so you know how to wire it and program it.
Can you get the manual before you buy it ?
Can you read it, is it in English ?
Do you understand it?


This one works.
It's supported in USA by people here on this forum and by a tech service department that answers the phone

http://www.electricmotorwholesale.com/9520-KBAC-27D/
 
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