FactoryMation and Dealerselectric recommend different VFD's; Help me choose

Hello everyone,

I recently purchased a small, old Rockwell milling machine with a ¾ hp three-phase motor, and I want to power it with a 1 hp VFD from 220 single-phase.

After reading through some of the posts here, I contacted FactoryMation and dealerselectric, and, based on some of the features I want, they recommended drives.

FactoryMation recommends: TECO 7300CV

Dealerselectric recommends: TECO V3-201-cs (This is a new model, apparently).

How do I decide between them?

Teco seems to have added a few new drives to their lineup. Is it good to go with new?

The features I think I want:

• Sensorless vectoring
• Dynamic braking, with an added resistor (sourced from elsewhere)
• The ability to add a remote drum-switch, E-stop (I am new at this), and a speed/ frequency POT—all at the same time.
• The drive will be mounted in a large metal cabinet, so I don’t need to pay extra for a NEMA 4 enclosure

They sell for about the same price.

Both drives have the ability to have the keypad/ screen assembly remote mounted—with the purchase of a $40.00 cable—ouch.

Which one of these drives do you recommend?

I don’t know much about VFD’s; what features, abilities, etc. separate the 7300CV from the N3?

Do I need to make sure that a drive for a mill has any other specific features?

Do the drives above have everything I need?

Any advice, opinions, detailed feature analysis/reports, general banter, and rantings/ravings will be greatly appreciated.

PS. sorry if this post is impossible to read. I wanted to get it all in, and now it's all incoherent--Darn you, cut-and-paste.

Bill

First post, good question

If you want the least costly Teco vector drive, look at the EV Series:

http://dealerselectric.com/item.asp?PID=417

Display does not detach, fewer bells & whistles, but strong performance at low cost.


The 7300CV is physically larger, which may or may not matter in your application. I've configured the nearly identical MA7200, also with detachable digital operator, and the connecting cord looked like a telephone cable ... $40 seems high, you may be able to cut & splice your own. Mount the drive out of harm's way, put the digital operator where you need it, plug-n-play. More money, more features.

Some people on this forum use the N3 & will hopefully comment. I know not much about them & have never configured one.

Hitachi & ACTech are a couple of other popular brands if you want to look at more options, but cost more.

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Barry Milton

I use AC Tech drives and have been very pleased with them.

That's not to say anything against Teco. They have an excellent reputation. But I'm not familiar with specific models.

You have to be careful when sizing a drive for operation with single-phase input power. Some will deliver full power in that configuration, while others must be de-rated 50% or so, meaning you'd need a drive rated at least 1 1/2 hp for your 3/4 hp motor.

The only way to tell is from the manufacturer's literature for the specific model series under consideration.

I rather doubt that you need a braking resistor with a 3/4hp drive.

And welcome aboard.

- Leigh

Vfd

Thanks Barry,

I appreciate the help.

You mention a couple of drives in your post, and I am interested to learn about them.

Can I connect a POT, drum-switch, and an E-stop on the EV-series drive?

I like inexpensive.

It is not important for me to have the detachable digital operator--unless it should be. I really don't know.

Will the ability to see the digital readout enable me to see the spindle speed or give me some other kind of data I would find useful?

You mention bells and whistles.

I like them too.

Where can I find out what to look for when I look at a drive at one of these retailers websites?

Is there a primer on VFD's for the layman? A quick and easy chart?

Thanks again for your advise.

Bill

Thanks Leigh,

I thought the AC Tech drives were a bit on the pricy side, but that could be because when I read about them here it is when someone is recommending a NEMA4 enclosure.

I will look at them again.

I was under the assumption that a drive only needed to be derated 50% when it was initially designed for three-phase input and is currently connected to one-phase.

Do some drives require this derating even when they are advertised as single phase input?

Thank you for the advice about the resistor. I had a suspicion that the internal braking could handle it but that was only a guess.

Thanks again,

Bill

I thought the AC Tech drives were a bit on the pricy side, but that could be because when I read about them here it is when someone is recommending a NEMA4 enclosure.

Click to expand...

That was probably me, as I currently have three SMVector drives & two of them are NEMA-4X. I like simplicity, so the NEMA-4X drive lets me mount the unit where the touch pad is easily reached - which also means that chips & coolant assault the drive regularly. The NEMA-1 enclosure is roughly $90 less, depending on size.

Most drives 3 hp and smaller can be purchased as 3ph input, or as 1ph input without derating. There are some older drives (sometimes seen on eBay) that are 3ph only & require 50% derating.

I rather doubt that you need a braking resistor with a 3/4hp drive.

Click to expand...

+1

Braking resistors are needed when there is a high inertial load to stop, or when you want instant stop from high speeds. A small rotor (in the motor) driving a light spindle with smaller tooling has not much inertia, a lot like a drill press (which I have on VFD). The drill press will instantly stop at slower speeds, up to 200-300 rpm. Above that, it takes anywhere from one second to a few seconds to decel to stop. You can play with the decel time, starting long & dropping down one second at a time until the drive faults from high buss voltage. You will probably find that it stops fast enough without the braking resistor.

Will the ability to see the digital readout enable me to see the spindle speed or give me some other kind of data I would find useful?

Click to expand...

Probably. You'll need to print out a chart that links Hz to spindle speed on each of the four pulley steps.

Can I connect a POT, drum-switch, and an E-stop on the EV-series drive?

Click to expand...

Without any problem.

Is there a primer on VFD's for the layman? A quick and easy chart?

Click to expand...

Whomever invents that can retire in a year Lots & lots of info in this forum, without a doubt the best VFD information source on the web. Take a look at some of the many VFD installs that have been done & you'll get a bunch of ideas. The best teacher IMO is experience, and you'll know ten times more after doing just one.

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Barry Milton

If you only want remote control without the keypad, why aren't you looking at the TECO JNEV series? They are about $135 and will accept a speed pot and remote stop/start.

why aren't you looking at the TECO JNEV series?

Click to expand...

Teco does not have a JNEV series, but they do have the EV series drive, which I suggested in the second post. All the model numbers for the EV series start with the letters JNEV, but there is no JNEV series.

http://www.tecowestinghouse.com/PDF/EV_Micro_Drive.pdf

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Barry Milton

cryptrx1 said:

I was under the assumption that a drive only needed to be derated 50% when it was initially designed for three-phase input and is currently connected to one-phase.
Do some drives require this derating even when they are advertised as single phase input?

Click to expand...

Hi Bill,

All (?) drives are designed for three-phase input power.

Many can operate from single-phase input, but not all.

Of those that can, some must be derated, while others can operate at full rating. You must consult the manufacturer's specs.

For example, the 5 hp AC Tech drives that I use will run a 5 hp motor with either single-phase or three-phase input. That's the reason I chose the AC Tech drive, since it was cheaper than a 10 hp model. This is the only 5 hp drive I know of for single-phase input.

- Leigh

Thank you, everyone.

Barry and "Waterlogged," I am going to take your advice and buy the EV-series drive from Dealerselectric.

Leigh, I had no idea. I think it would be a good idea for me to look into how the units work. It will help me make more informed decisions. I understand that a VFD rectifies AC to DC and then inverts the DC to AC, but never looked into just exactly how that is all accomplished. That will change.

Thanks again,

- Bill

Just FYI and for what it's worth, in an effort to explain why they might promote different products from the same manufacturer...

Factorymation is an on-line only distributorship that is partially owned and financed by Teco themselves. But to avoid conflicts with their established distribution chain, they can only sell "last year's models" of drives. So in essence, Factorymation is the "Outlet Store" for Teco. They sell NOS (New Old Stock) with full factory warranties, but not always the latest and greatest (L&G) drive products. Many of the other Teco products they sell, such as the PLCs, contactors etc., are L&G because Teco has had difficulty setting up traditional distribution for those products in a saturated marketplace. Drives and motors however have a long history here in the US and are widely distributed through the old Westinghouse Motors distribution chain, so they had to avoid pissing those guys off. They have also now expanded into other products such as Weg, Cutler Hammer etc., but as far as I know, their charter with Teco as the NOS drives outlet remains the same.

Dealers Electric, although originally only a surplus reseller, is apparently now a full fledged Teco authorized distributor so they are able to promote the L&G product. However, they are also still a surplus buyer and have NOS product they buy up from other Teco distributors as well. That means what they really promote most is what they have on the shelf and that may be both NOS or L&G.