Phase converter question

D

DHackney

Joined
Jul 12, 2004
Messages
178
Hi folks,

On last Friday there was a thread related to phase converters for 3-phase motors. I am completely and thoroughly electrically challenged and would afraid to try building a home-made rotary converter. So.....

I took the initiative and found some converters for sale at the Surplus Center site and was wondering if someone of you electical genius folks could tell me if this item would be all I need to hook into and use a machine with
a 3-phase motor?

Here's the link:

http://www.surpluscenter.com/item.asp?UID=2004121311353195&item=11-1877&catname=electric

Many thanks,
Dana Hackney
Monument, CO
 
Dana, I see no reason why you could not safely run up to a 3hp motor on this converter. Just don't expect to run more than one motor on it. These static converters are great for the low-horsepower motors, and I'll say up to 3 hp would work fine on that one. Many folks use these if they only have one 3-phase machine in the shop, but if you get more than one, or say a huge lathe with 5ph or better, then a rotary converter will save you a lot mor money in the long run than buying several static-types.
 
Shows you how muc I know. I did not realize that it was a static
converter. I tho't I was looking at a rotary one. Duuuhh!

Thanks again, Jeff.

Dana
 
Dana,

Don't do it. That is a Phase-a-matic product. It is junk! It is a scam. I've been burned by the bogus marketing ..."Three phase motor will produce approx 2/3 of its rated HP." This is absolutely not true. You will get less than 1/3hp from this device.....I've had them...I studied them....I'm very bitter about throwing my money down the drain on this product. I'm even more bitter about the money spent to rewind the motor that was fried with this product. It is just a capacitor used to make a 3ph motor start. Once it starts...the 3ph motor runs on 1 leg...not 3...or not even 2. Once the motor is running....this device completely disconnects from the circuit. Heck...you can use a pull rope to do this.


Sorry for the negativity.....it's been about 8 years...and I'm still smokin' hot about my experience with it.

By the way...this is just my opinion...there may be folks that have had good luck with these things....at least...the manufacture told me that.

....one last thing....don't do it! :D

Sincerely,
Rob
 
Hello Dana

You are better off getting a real VFD (Variable Frequency Drive) for an extra $100 or so. You will get way better results such as easily variable speed, full torque from zero to full speed, overload protection...

A VFD will take up way less space too. Someone posted the following link (www.dealerselectric.com/FM100.html) for a Teco/Westinghouse VFD that is an industrial quality product that should serve you well for a long time and cause you way less headaches.

You can also try calling the various VFD manufacturers to see if they have refurbished units available. Toshiba, where I work, sell appropriate ones for about $200. Feel free to contact me if you are not able to find anything on the Dealers (or other) sites.

Good luck.

Phil
 
I've got a Phase a matic on my Bridgeport (came on it) and it hums even when the machine's turned off. I've also managed to stall the machine when taking drilling aluminum with a 1" silver and demming drill after drilling a 1/2" pilot hole. I'm thinking that for Xmas I'm getting one of those TECO VFDs and will be removing the Phase a Matic. If I do, you're welcome to it cheap. It does the job, but just barely.

John
 
rfrink said:
Dana,

Don't do it. That is a Phase-a-matic product. It is junk! It is a scam. I've been burned by the bogus marketing ..."Three phase motor will produce approx 2/3 of its rated HP." This is absolutely not true. You will get less than 1/3hp from this device.....I've had them...I studied them....I'm very bitter about throwing my money down the drain on this product. I'm even more bitter about the money spent to rewind the motor that was fried with this product. It is just a capacitor used to make a 3ph motor start. Once it starts...the 3ph motor runs on 1 leg...not 3...or not even 2. Once the motor is running....this device completely disconnects from the circuit. Heck...you can use a pull rope to do this.


Sorry for the negativity.....it's been about 8 years...and I'm still smokin' hot about my experience with it.

By the way...this is just my opinion...there may be folks that have had good luck with these things....at least...the manufacture told me that.

....one last thing....don't do it! :D

Sincerely,
Rob
Click to expand...

Sorry to hear you got burned, Rob. I have heard some horror-stories about static converters, but have never witnessed any in person. Some of the shops I've worked in have had static converters on every machine under 2hp, and they all seemed fine. Personally, I convert all my 3-phase to single when converting old equipment anyway. If I set up a commercial shop in NC, I'll try to find local grid 3-phase, and 408/480 - just in case I get a really big lathe or something.

Dana... what are you going to run on that thing? I belt grinder?
 
Hi all,

I am trying stay ahead of the game by having a converter on hand just in case I find a good deal on some older disc sanders, surface grinders or mills.

Rob, I am about to go with your 9" disc for my older 3/4 delta (1750 rpm) motor for my disc grinder. Would you suggest the one with the rounded shoulder or the 90 deg edge? It might be a bit before I can afford it as I've been trying buy all the other stuff I need :eek: By the way, I finally got the KMG set up. I mounted it on my bench (on a 2x2x1/4" plate), hooked up the 2hp Baldor to a big hinge and attached a cable to the opposite side of the motor's plate (with weights at end) that runs through a hole that goes through the bench. That way I can simply push up on the hinged motor and change the shieve arrangment - poor mans variable speed :) .

Many thanks folks for all the help and advice. This is such a great resource for the knife maker (novice to expert). You guys are great!

Dana
Monument, CO
 
Hi Phil,

Thanks for the link. I will add you to my favorites list and make a note about a used/refurbished converter for the future. $200 sounds like a great deal!

Thanks again,
Dana
 
I know I hit alot with this one site, but there is some really good stuff there.

Lindsaybks.com has a very breif book on running 3ph motors on single phase power. I bought it. I think it was like 3.95 or something like that. It goes through the explanation of the three different types of phase converters, and the ins and outs of each. That capacitor version that someone was talking about is for starting only,a nd on light or no load motors.

If you haven't ordered a catalog I would suggest you do it. It is free, and there is no telling what you may find of interest in there.

Doc
 
Dana

If you are interested in a refurbished Toshiba VFD, I can find out what they have in stock and the prices. You can then compare with the prices from Dealers (or anything else that you find) to see which is the better deal. I have no financial interest in this since I work in a different department.

Please keep in mind that not all models of VFD's are capable of running from 240V, single-phase. Most of those that can will have a reduced capacity. This issue has been discussed on this forum before.

Phil
 
Thanks a lot, Phil, for your help.

I would be interested in what the cost would be of one of the Toshiba
converters. I might have to wait a while before I can order one but I would like to get a ballpark figure of whow much it'll set me back.

Kind regards,
Dana
 
Hello Dana

Please let me know the hp rating of the motor that you want to run using the VFD. Please also confirm that you will be using a 240V single-phase mains. How long are you likely to wait before purchasing one?

Take care.

Phil
 
I might be interested in one as well. I would need to power a 1 HP three phase motor on my Bridgeport. I have 240V single phase available.

John
 
Hi Phil,

Sorry for taking so long to reply!

It'll be, probably, mid-year before I'll need one (and can afford one).

Please forgive my electrical knowlegde but when you say 240V single-phase mains, are you referring to the motor (3hp 3phase) on the old equipement (surface grinders,...), or are you asking if I'm running off 220 power in my shop :confused:

Currenlty, I've got both 110 and 220 supplied to my shed and am running my KMG (1phase 2hp 220) off of the one 220 outlet.

Probably giving you too much info but I want to make sure I'm answering you correctly.

Thanks Phil,
Dana
 
I love surprises. I was just surprised with a Christmas bonus! Yeah! That means I'm definitely getting a VFD for my BP for Christmas. The question now is, will it be one of Phil's refurbed Toshiba units, or that Teco 1 HP unit that's just under $200.00 at Dealer's Electric, to as to time frame Phil, immediately would be my answer.

John
 
Dana

My question about the 240V mains was in reference to the supply that you have (220V).

What do you want to run with the VFD? You mention a 1hp, single phase motor on your KMG grinder. You will not be able to use this with the VFD. You will have to change to a three-phase motor. You also mention a 3hp, three-phase motor on a surface grinder.

If you set up a change-over switch or have some plugs and sockets, you can run multiple motors from the same VFD, but not a the same time. The VFD must be chosen to accomodat the biggest motor that you want to run.

Let me know when you are ready and I can check to see what they have in stock at that time. You may also decide that a new one for similar money from Dealers may be a better deal for you.


John

I will check to see what they have that may be suitable for you tomorrow. I think that they will have gone home by now.

The $191 Teco would probably work for you though you may want to consider spending an extra $59 and get the 2hp one. That would allow you to use it with a grinder, or some other equipment, that needs up to 2hp. It will be less likely to trip out if you overload your 1hp motor and it will run a lot cooler, leading to a longer life for the VFD. The 1-3hp Teco's are some of the few that I have seen that allow full rated power when running from a single-phase supply. A typical single-phase supply will not be able to support a load greater than 3hp. The Teco's also look like they have an input that can be connected to a potentiometer to control the motor speed. One would have to look in the user's manual to confirm this.

You may want to ask Dealers about buying a brake resistor (FM100-2BR1 for $19 or FM100-202-N1 for $24) for the VFD. Adding a brake resistor will allow you to program the VFD so that the tool will stop really fast.

Phil
 
Hello

I checked with our VFD R&D Manager and our VFD Marketing Department to see what they could offer.

They gave me alist of older/discontinued/refurbished VFD's that they are selling at reduced prices. They recommend using derating the VFDs to half capacity if it is a 3-phase input model and is being used with a 1-phase input. Most of the ones on the list are probably too big (say 20hp) and/or too expensive (over $1000-$2000). Many probably have some special accessories or features tht you would not need and would not want to pay for. The following are the ones that I felt might be useful to you guys.

VFS7 2hp, 3-phase 200-240V input (3 available) $191
VFS7 2hp, 3-phase 200-240V input refurbished (1 available) $143
VFS7S 2hp, 1-phase 200-240V input (2 available) $150
VFS7 3hp, 3-phase 200-240V input (4 available) $143


For new VFD's, they have two series, the S11 and the VFNC1 (www.tic.toshiba.com/productpages.php?prod=S11&family=Drives). These are really compact. They normally sell these through distributors but they could sell them to someone with a credit card. The list prices are higher than for the TECO's from Dealers though. I am showing the prices for the some of the single-phase input models only. I think that the three-phase input models are slightly less expensive than the corresponding single-phase model.

VFNC1 1-phase 100-115V input, 3-phase 200-230V output (!!)
0.5hp $374
1hp $510

VFNC1 1-phase 200-240V input, 3-phase 200-240V output
0.5hp $326
1hp $358
2hp $452
3hp $496

S11 1-phase 200-240V input, 3-phase 200-240V output
0.5hp $400
1hp $500
2hp $600
3hp $700


Hope this helps.

Phil
 
Thanks for the info Phil. I don't want to turn this into real work for you, or seem too greedy, but I have a couple more questions.

These units are factory refurbs, is there any warranty? Is there any provision for a remote mount rheostat for speed control? Is there some sort of display to indicate what frequency is being generated? Are these units constant torque? Do they have the above mentioned braking resistor?

I'm most interested in the following units:

VFS7S 2hp, 1-phase 200-240V input (2 available) $150

I'd probably be interested in both units, depending on the above noted questions, if that's not being too greedy.

Thanks for the info,

John
 
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