VFD recommendations

[chrismunn]

Just picked up a Kent 3vk mill and don't have 3 phase in the garage.

http://www.kentusa.com/mills/manual-kne ... knee-mill/

The mill is 220v 60hz 3 phase. I don't know anything about VFDs so I'm not sure exactly what I need? I don't think I want a phase converter tho? I was recommended by someone who uses Allen-Bradley so I was looking at thier website and read up on the Powerflex 523.

http://ab.rockwellautomation.com/Drives ... #selection

I'll be honest, I don't really understand what I'm reading there?

And suggestions or input on this subject will be incredibly helpful. The guy I was talking to gave me a big list of brands but I don't know one from the other in terms of performance, so...?

[Magicniner]

All the big brands tend to be good, I prefer Siemens but I also like Mitsubishi and ABB. Siemens Vector Drives are my particular favourites, they react to load slowing down the motor by supplying more oomph to maintain speed.
Regards,
Nick

[chrismunn]

How do I know which VFD will be right for my machine? Is it just comparing numbers? Im assuming i want the output of the VFD to match what the machine needs? Can the output of the VFD be higher than the requirements of the machine without damaging anything?

[mcostello]

I bought a Hyang (or similar Eastern Asia spelling) would not program from the beginning. Factory gave a refund.

[Patio]

There was a good discussion on this awhile back. Do a search on VFDs. I would post a link, but I am not home and only have my phone.

[Magicniner]

A good VFD rated for your motor power will suffice, over power should still be fine but check manufacturer's specifications as some large VFDs will not run small motors well.

- Nick

[NP317]

I am waiting for delivery of a new milling machine, that includes a built-in Japanese brand of VFD phase converter. My single-phase 220Vac power will work directly with this mill's 3-phase motor.
Of note: The motor is 3 HP, and the electronic VFD is rated at 5 HP output.
~RN

[chrismunn]

Was watching Stan Zinkosky's YouTube channel and saw that he runs a VFD on pretty much all his machines. Was able to get him on the phone and based on my situation we decided that a rotary phase converter is better suited to my machine. The only advantage to a having VFD for me would be over driving the spindle RPMs and having RPM control with a potentiometer. But, since the head is already a variable speed geared crank control there's no need for the pot speed control and it's a 4200 RPM spindle. Plus if I ever end up with another 3 phase machine [within spec] in the shop I can just tie right into the existing phase converter, as long as I'm not running both machines at the same time. I didn't realize how much rewiring was involved with the VFD so I'll probably get on the horn with American Rotary next week for a consult? Got the mill going in tomorrow morning. Excited!

[medic0079]

I use a hitachi on both mill and lathe they work great and are easy to set up. I think they were 200$ shipped for 3hp of fleabay

[bill jones]

-I normally use a rotary phase converter that I have mounted down onto the left side of my mill---with a kick switch installed so I can turn it off and on real easy with my foot.

-I paid about $650 for this phase convertor in 1992 from a local electrical shop called Nelson Electric here in SLC utah----only thing it's needed is to have a little bearing grease about every 10 years.
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-I also occasionally use a Hitachi VFD---#NES1-022LB with the optional NES1-OP operating pad---particularly for slowing the speeds down below about 60rpm of the phase convertor.

-I machine valve seats on racing cylinder heads and they usually always like some speed around 30rpm.
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-the main issue I don't like about the VFD is it can't be instantly stopped and reversed like when threading.

-the VFD instructions doesn't want it to be operated thru a reversing switch as the VFD box needs a slow ramp up to speed when starting and then a slow ramp down speed to stop.
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-I always use the phase convertor---but I change back and forth between using the VFD.

-I built a yellow quick access hard wire box to where I can switch the three main wires from VFD to the phase convertor back and forth---takes about 2 minutes for this hard wire arrangement.

-this wiring system is sort of a cluster up on the top left hand side of my mill---but it is my way of having the convenience of either power choices.

-there is sort of a series of operational changes necessary to deal with when going between each system so I have made some lock outs so I can't screw up---like you can't use the hand brake lever with the VFD so I have a lock out under the lever---and several other lock out procedures to deal with.
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-I had a slightly larger blue Hitachi unit #X200-022NFU that cost a little over $200 and lasted for maybe 4-1/2 years then burnt up internally in one little spot on the circuit board that I couldn't fix---so when I got this black unit I installed a small computer type fan to blow air thru it to cool it better.

-I had got to where I was running the blue unit most all the time except when I was tapping etc.
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-both of my VFD's came from Drives Warehouse in Texas I think---this black one with the optional key pad cost $245.

[Patio]

Well Chris it looks like you gave Stan an idea for a YT video. He has posted one on RPC vs VFD.
https://www.youtube.com/watch?v=jh7v71uehH4

[spro]

I enjoyed the video and three after. It starts where RPCs are the best and then VFDs are the best, depending. Altogether interesting. I was watching the one in which the man was diagnosing and repairing a blown VFD. I found that I was talking to the screen Yes yes and wait. Think he was using a Fluke 66 and definitely a seasoned tech. All good info, thx for link. ( I need to get one of those push/grab test leads, alligators and loop fit aren't right).