VFD - What am I asking for?

Patrice Lemée

Patrice Lemée

Joined
Aug 13, 2002
Messages
5,703
Well I finally decided to go with 115V for now. Now that I have a little play money I want to go to the local electric motor place and see how much a motor with VFD would cost. I have a general idea of what I need:

1.5HP TEFC motor (115V)
VFD with Nema 4 enclosure

So, is that it? Is it what I am supposed to ask for or am I missing something?

Thanks

Pad
 
Well, for starters, a VFD is for 3-phase motors. Speed controllers for 115v single-phase motors are fairly rare and expensive (unless they're just a big rheostat, in which case you're wasting most of your electricity as heat.)

So depending on your budget, you'll want a 2HP VFD (simply because they don't make a "1.5HP" VFD) and a 1.5HP TEFC 3-phase motor. I can't say on the motor, as prices are all over the place depending on brand and whether it's new or surplus, but a 2HP VFD from Automation Direct is $265. You'll have to provide your own dust enclosure, though.

Doc.
 
I am needing this info as well. Never really got it.:o
So does that mean I need 3 phase in my shop? (or Pad's shop)?
Thanks,

jm
 
Why would you run a 1.5HP motor at 115V AC? Its going to pull over 20 amps. Why not bump it up to 220 and pull under 15? Are you limited at your power panel, or is there some other reason you're going with 115V?
 
Ok each time I think I know something, seems I don't. :(

I was talking about something like Rob at Beaumont Metalwork offers. I thought that this was a single phase motor. I can't run 3 phase on house current can I? I need a phase converter?

Pad
 
FiddleB, again I thought that Beaumont's package ran on 115V. Not going to 230V was mainly a $ concern, mney is tight right now and I need more "toys" too.

Pad
 
You can run 3-phase motors on a single phase if you're getting a vfd. Doesn't matter if you run 110V or 220V, you'll be using about the same total amount of power unless you are comparing apples to oranges in motor types.
 
an old treadmill motor with controller will work and you can usually find one cheap with a little digging.
 
AcridSaint said:
You can run 3-phase motors on a single phase if you're getting a vfd. Doesn't matter if you run 110V or 220V, you'll be using about the same total amount of power unless you are comparing apples to oranges in motor types.
Click to expand...

See, although I really appreciate the help, this sounds like Japanese to me.I just get more and more confused. :confused:

A 3 phase 110V motor? VFD instead of phase converter? :confused:

Pad
 
The three phase I'm speaking of is 220V. You had expressed concern that you can't run three phase from your home wiring. The VFD acts as a phase converter to go from single phase 220 to three phase.
 
ah ha!
all you need is 220 (single phase) and the VFD (what ever that is) gives you 3 phase!!!! Wow!
thanks


jm
 
Padrig,

Shop around on the internet. You can find the KB controllers for somewhat cheaper. Look for the KBAC-27D for 110v at 1.5 HP or 220v at 2.0 HP.

The input is single phase and the output is three phase. Make sure to get nema 4 or build a dust box to protect your VFD.

Then, look locally for a cheap 3 phase motor, 1.5 HP motor.
You can run the 1.5hp and up grade later to 2hp and 220v.

Kelly
 
Hey, I'm no electrician by any means, but I was able to do it.;)

Seriously, you need to make sure that the wiring is correct prior to starting the motor, but you can also find the wiring diagrams too.

I think they have been posted on bladeforums in the past.
 
These two threads cover a lot of what you want

I posted some links to the factory spec sheets of VFD drives in those threads. I'm sure they are available cheaper somewhere else but it's good info.

Most controllers are rated at 2 HP, there is a price jump to go up from there.

http://www.bladeforums.com/forums/showthread.php?t=568784&highlight=vfd


http://www.bladeforums.com/forums/showthread.php?t=563787&page=2

The KBAC 27D i think is what rob frink sells, it's the same specs as he quotes
It's available in Canada through the company's distributors and online.

nema 1 = not dust proof and cheaper, nema 4 is dust proof and slightly more expensive
It's easier and cheaper to just buy a nema 4 rated controller,
not just a dust proof enclosure, the heat sinks are designed for that enclosure type.

There are special motors rated for VFD use, but i don't know anyone that uses them.
normal cheap 2 hp TEFC 3 phase 220v motors work

Or to confuse you... you could use DC power, see Stacy's posts for that.
there are benefits...


KBAC 27 D info page on company website
I use the website to contact the company for local companies that stock it.

http://www.kbelectronics.com/catalog_nema_4x_ac.htm

Quebec Dealers
http://www.kbelectronics.com/s_view.php?id=680&db=df&area=&area_both=&stock=1&line=a&name=

http://www.kbelectronics.com/s_view.php?id=958&db=df&area=&area_both=&stock=1&line=a&name=

http://www.kbelectronics.com/s_view.php?id=672&db=df&area=&area_both=&stock=1&line=a&name=
 
Last edited:
Thanks Steve, I had read those 2 threads and it seems I still was in the dark about the whole thing.
With the links you gave me I feel I am starting to understand a little more.
So first step is to have panel wired for 220v. I believe I need two slots and that's all I have left if I remember right.
I'll go to my local electric motor place and see what they say with the nfo you and other gave me.

I'll let you know what happens.

Thanks again.

Pad
 
Well, I finally went to the motor place. The guy is gonna call me back with a quote for:

1) 2hp 3 phase 220v AC with VFD Nema4X
2) 2hp DC with controler

Thanks again.

Pad
 
Padrig,

The motor place will probably be pretty expensive. I have been looking for a new inverter as mine is acting up. If you have 220v single phase available you should have no problem running a 1.5hp 3ph motor with a VFD. The pricing I have found for the controller is $100-$150. If you can wait ebay has them for even less but you need to keep on it to find them. See if the Motor shop will give you a written estimate with model numbers and do a little on-line shopping for comparison. Might be able to save a few bucks. JMO
 
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