VFD/Motor Questions

Taz575

Well-Known Member
Ordered up the Ameribrade Fastback, Combo platen and small wheel arm. I am starting to rent a house right around the time when the grinder arrives, so I will have to move my shop over to there. I was looking to use the 1HP motor I have now with step pulleys 1.5" and 5" on the motor, 2, 3,4, 5" step pulley on the drive shaft with a 4" drive wheel), but since I am moving, I may look at a 3 phase motor and VFD for the belt sander. I previously had a VFD (KBAC 24 or 27 IIRC) on my KMG and 2 HP 3 phase motor set to run off 110V, but that is an expensive option at the moment ($350-$400 for the KBAC alone). There aren't many VFDs that convert 110 input to 220v output and can handle larger motors.

I don't think the landlords will let me have a 240v leg run out to the shed since we are only renting the house currently. The garage is detached, but near the wash room with 240v outlets for the washer and dryer, which got me thinking.

Can I run a long extension cord from the outlets the washer/dryer plug in to out to the garage/shed to run the VFD/Motor that way? That way I would have to spend around $100 on a heavy duty extension cord, but wouldn't need to rewire and I can get a cheaper VFD since I wouldn't need one to convert from 110 to 240 and wouldn't lose the HP that way, either.

What about those step up devices where you plug them into 2 different 110v outlets to run a 220/240v device? Would any of these work with a 2HP motor and VFD?

Would this VFD work?


I like that I can get a cable and have the control panel located near me so the VFD box can be farther away from the grinder/dust.
 

Self Made Knives

Well-Known Member
When I bought my first welder many years ago, I lived in an older house that had a jam packed breaker box with no room. The laundry room was right next to the garage, so I went down to Lowes and bought 75 feet of heavy 3 conductor cable and the plugs to make my own extension cord. I plugged it in to the dryer plug anytime I need to weld and could reach all the way out the driveway fine. Used it like that for a long time. You'll just have to fight the wife for plug time.
 

Taz575

Well-Known Member
That is good to know! We have the washer/dryer on opposite walls, so I have 2 plugs, so I can swap out back and forth if needed! We can work out the laundry schedule if needed, I just wasn't sure if it would be an issue with the long extension cord into a VFD.
 

Self Made Knives

Well-Known Member
I think it will be fine within reason. Don't cheap out on wire and get too small or go too far. If you standardize the socket end of the extension cord, you could run the grinder, a kiln, even a big milling machine if they all shared the same style plug. In the long run, make the landlord a knife and sweet talk him into adding a small panel to the garage so you don't have to fool with cords.
 

Taz575

Well-Known Member
I gotta convince the fiance/soon to be wife that I should work in the garage instead of the shed. I will do a plastic curtain to keep the dust contained since the Garage has power, but I don't think the work shed has power. If we buy the house, I will probably set up the workshed as my shop.
 

John Wilson

Well-Known Member
The laundry room was right next to the garage, so I went down to Lowes and bought 75 feet of heavy 3 conductor cable and the plugs to make my own extension cord. I plugged it in to the dryer plug anytime I need to weld and could reach all the way out the driveway fine. Used it like that for a long time. You'll just have to fight the wife for plug time.

BINGO. I ran my grinder that way for two years.
 

Taz575

Well-Known Member
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EdCaffreyMS

"The Montana Bladesmith"
Whew! 40-50'? I've never made/used an extension that long for 220V..... but I can tell you that with 120V at 50', your voltage will drop about 3.5%.

I would err on the side of heavier, and recommend at least 10 gauge and would prefer 8 gauge, which will be pricey. I can tell you that a typical dryer "pigtail" cord that is only 6 ft. is at least 10ga..... and the "premium" ones are 8ga. I'm not certified electrician, but have wired my fair share of knife and blacksmith shops over the years, and will say that when dealing with 220, no matter what the draw is, your safer all the way around with heavier gauge wire.

If I understand correctly, you're in an apartment? (by the way, why are the not called "togethers"?), and I suspect if a landlord found you were doing something of this nature, you'd be out in a flash..... so I'd say not to take ANY chances. ;)
 

Taz575

Well-Known Member
I am renting a house from a family friend and they are OK with me using part of the garage as a shop. Their daughter is a Chef in Boston, so they want to see some of my kitchen knives, too that I build from kits and rehandle.

I will measure the wash room to the garage to get a better idea of the distance, but it looks like 30' or so. Since the VFD comes with a 2M control panel cord, I may mount the VFD closer to the door (away from the grinder and dust) and use the 2m cord to my advantage, or get an even longer controller cord for it so it would be a shorter extension cord run.

I found some 6ga and 8ga extension cords for MIG welding, so I may go with one of those if I go that route. I definitely want a heavy gauge cord!

I will also ask if I could have a 220v leg run out to the garage (it already has 110 out there, but I am not sure if the panel has enough space for another leg) and see what that would cost (it would depend if the panels have space in them or not) and if they would be OK with it. That would be my preferred option, I am just not sure if they will go for it? The guy grew up in the house and his dad had a shop in the garage for wood stuff like picture frame making, etc.

The other option is to get a converter box to step the 110v up to 220v, I would probably need something in the 3000-5000 watt range I am guessing? Do you think this would be a better option?
 

jaxxas

Well-Known Member
In my brief experience an 8 gauge 3-conductor copper wire extension cord for 30 amps @ 30-50 ft shouldn't be an issue, use 6 gauge for 50 amps or just for an extra safety margin! My 3 phase 2 hp grinder only pulls about 7 amps on startup and a bit less when just running, 8 gauge is fine. Underground runs of 240 volt 8 gauge cable is rated to about 150 ft with not more than a 3% drop. A caveat is not using more than a single tool on the circuit at any one time. Bigger is better with these things! Assuming it's an outdoor run a good tough UV protected abrasion proof jacket may be required.

ymmv
 

Taz575

Well-Known Member
Landlords are OK with me running a 240v leg to the garage, but the original wiring runs under the driveway, so I may have to see about how to go about the cabling. I also need to set up our electric panel to be run by a generator outside, so I may do both projects are the same time if I can afford it!
 

Taz575

Well-Known Member
It was years ago, so I have no idea. I am going to have an electrician come out and check the panel and give me a quote to get the panel set up to be powered by an outside generator and also to run 220v to the garage. Fingers crossed!
 

Taz575

Well-Known Member
Well, Fed Ex seemed to have "misplaced" the 100# crate from AmeriBrade with my belt sander in it, but the good news is a friend of mine is an electrician and can check out my system and get me set up and do the generator hookup at the same time! Looking forward to a 2 HP 3650 rpm running off of a VFD! I am running a 1 HP 1750 with step pulleys on a home build 2x36 small wheel grinder and I get a lot of slippage with the belt and pulleys if I put much pressure on it.
 

Sean Jones

Well-Known Member
Well, Fed Ex seemed to have "misplaced" the 100# crate from AmeriBrade with my belt sander in it, but the good news is a friend of mine is an electrician and can check out my system and get me set up and do the generator hookup at the same time! Looking forward to a 2 HP 3650 rpm running off of a VFD! I am running a 1 HP 1750 with step pulleys on a home build 2x36 small wheel grinder and I get a lot of slippage with the belt and pulleys if I put much pressure on it.
Fed-Ex seems to be doing this a lot lately
 

MTBob

Well-Known Member
I think I am going to go with:
https://www.electricmotorsforless.c...tor-3600-rpm-3-phase-tefc-PR56C2M2A_p_38.html

VFD:

I will make my own extension cord so it has the dryer plug on one end and bare wires on the other to go directly to the VFD. What gauge cable should I look for? 8, 10, 12? It will be around a 40-50' extension I think? I was going to use the same cable to wire the motor to the VFD, any issues with that?

Any thoughts with this setup?
Like Ed said...wow, 40-50 ft, sounds questionable, personally I wouldn't do that. However I routinely connect a 220v plasma torch to 15ft (either #12 or 10 wire) extension cord.
Be sure to verify that the motor you are selecting is designed to run with your controller. See recent discussion on this topic.
I'm running a 2x72 with a KBAC 27 connected to a 2hp motor and use 110v input. I have yet to find any grinding application where I think I need go to 220v. Perhaps others have different experiences, but 110v works for me, so far.
 

Taz575

Well-Known Member
With 110V, the KBAC is very expensive and the HP of the motor is limited. With a 220V input to 220V output VFD, it's much less expensive for the VFD unit itself.

Where is the recent topic about the motor and controller?
 

One Armed

Well-Known Member
Alway, always go 220 with anything over 1hp (750watts). A 2hp motor is not running full 2hp with 110v. I run a 1.5hp on 220v, and I haven't stalled it once with the most pressure I’ve put on it. I’m sure I could, but it would require an effort to do it on my part.
 

tkroenlein

Well-Known Member
With 110V, the KBAC is very expensive and the HP of the motor is limited. With a 220V input to 220V output VFD, it's much less expensive for the VFD unit itself.

Where is the recent topic about the motor and controller?
Drop the models in here that you're looking at. My KBAC 27D does both 110V or 220V, so there's no difference in price. That is a 230V 3 phase output.
 

Taz575

Well-Known Member
I am looking at this Chinese VFD:

It's rated for 3HP and 12 amps, I am looking at a 2 hp motor, so I think it should be OK?

I would mount it away from the grinder and use the control panel on the cord instead of having it near all of the dust. I am going to make a plastic sheeting "booth" to keep the bulk of the dust contained and under control as well.

I wanted to get the Iron Horse motor, but the 2 HP 3600 is out of stock currently.
https://www.electricmotorsforless.c...tor-3600-rpm-3-phase-tefc-PR56C2M2A_p_38.html or a Cobra Line motor are other options unless someone has another solid brand that is in the $200-$300 range?

Poking around the garage sub panel box, I see the garage door opener is on a joined circuit and I have other separate circuits in the garage. Will an electrician be able to use 2 of those 110v circuits to make a 220 v circuit with rewiring and putting a plug in? I typically only run lights and 1 piece of machinery at a time in my shop, so I would have the 220v outlet dedicated to the belt sander and run the lights and other equipment (bandsaw/drill press/toaster oven one at a time) off of the other circuit. I don't see why the motion light needs it own 20 amp circuit? Or why the garage door opener is joined together? Something above my expertise, so I want an electrician to look everything over for me.
 

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