Power for 1hp mill

I just purchased a 1955 Cincinnati Toolmaster 1B with a 1hp 220v 3ph motor. When I get it home what is my best option to power it. It will be the only piece of eqpt that I will be powering.

VFD.

Yup, what Bob said.

Can you help me out a little more and be specific? I am totally new to this. I searched thru the archives, but Im still a little confused as to what I need.

thanks.

Take a look at http://driveswarehouse.com , http://www.dealerselectric.com & ebay. You want a VFD with 230 V single phase input and 1 hp rated output. I've had good luck with TECO FM-100 and Hitachi L-100 units. The latter even comes in a 1 HP version with 115 V input and 230 V output, so you can plug it into pretty much any old outlet. I have the 1/2 HP version. I have also had good experiences with LG and Taian MicroPaq VFDs.

You will rewire the mill so that the VFD does all the switching of the motor power and the old on-off switch is relegated to switching little bitty control voltages into the VFD. You can also get rid of the old on-off switch and control everything from the VFD front panel. However, I find that less convenient and iffy in an emergency stop situation. Beware that many cheap VFDs are not suitable for mounting in the open. They must be mounted in a protective enclosure to keep out prying fingers and flying chips. The ones rate IP20 are like this. The one rated IP21 and higher can be used in the open. Is there room in the mill's column to mount one? I think that would be viable.

Don't mind Bob and Forrest, they're just having a bit of fun. They will be two of the best resources on this site as you get more into this.

Anyway, a VFD is an electronic device that allows you to control the speed of a 3-phase AC motor. Another benefit is that they can convert single-phase input to 3-phase output. This makes them ideal for home shops, especially if you are only going to run one machine.

VFDs are great devices, but they do have limitations. The main one for machine shop use is that they cannot be used as 3-phase "power supplies" like RPCs. In other words, you cannot plug in a bunch of stuff to the output of a VFD and switch loads on and off while the VFD is running. They are designed to operate 3-phase motors only, and if you want to switch the output of the VFD from one motor to another, you need to stop the VFD, make the switch, and then start the VFD again.

In your case, you will need a VFD that is capable of single-phase input (assuming you only have single-phase at home) and is rated at least 1 Hp. Some VFDs are fully rated for single-phase input. In this case, just get a 1 Hp and you should be fine. However, some others are only fully rated for 3-phase input and require derating when used with single-phase input. In this case, you will probably need a 2 Hp unit to run your 1 Hp motor.

Now for the sales pitch: I happen to work for a VFD manufacturer called AC Tech (www.actechdrives.com). We make a few VFDs that would be perfect for your application. We even make ones that will run from 120 Vac input and give you 3-phase 230 Vac output. If you are interested, let me know where you are located and I'll put you in touch with a local AC Tech distributor.

I'm sure other contributors to this site will have other suggestions as well.

Good luck!

John

You say "It will be the only piece of eqpt that I will be powering". That's today; how about a year from now?

I started with a one mill (3 phase); I now have 5 3 phase machines in my basement shop. A RPC will let you operate several machines simulatenously. I also have 3 machines operating on VFD's (they were operating from the RPC, but I needed easier speed control).

If you think you will ever have multiple machines, better think RPC for economic reasons.

Howard. I have seven three phase machines eacch running from its own VFD.

For those who are happy with a rotary phase converter or those with multi motor machines not lending themselves to ready VFD control retorfits I suggest you stick with the RPC.

The convenience of a VFD (infinitely variable motor ROM, full motor torque to near zero RPM - YMMV -, controlled accel and decel, etc) is a real spoiler in most situations where three phase motors must be run from single phase. They cost more but shrewd shopping can save a lot of bucks.

OTH don't automatically rule out an RPC if you're thinking about future three phase machine tools and getting them running from single phase with the minimum capital outlay. You can build your own RPC from mostly junk and an operable three phase motor.

VFDs definitely have advantages, and patient shopping can get you a high-end model at low price.

To me, main advantage of a big RPC in a shop is having three phase always on at multiple receptacles. But then that's just my personal preference. I also favor multiple idlers, at times with run cap toggle switching to achieve nice output regulation.

Nineteenhundred,

I put Mitsubishi FR-A220-1.5K (2.0 hp) VFD's on my Bridgeport, drill press and band saw - power them from single phase. Really love the quick speed change ability. I have more of these units. New, still in box, $200.00 + shipping. e-mail me if you (or anyone else) are interested.

I still use a RPC for other machinery.

Howard