1-3ph VFD install on 3 ph Drill press

[CarterKraft]

Entropy was asking about this another thread and I thought this might help the NON pixie wranglers get some old iron working again.

I have a "Buffalo 18" Drill press from Canada that is old school bad ass iron. Heavy duty everything, big bearings, big belts etc. It has a (I think) 3hp 3phase motor running at 1710 RPM for a low speed of 400 rpm. That's good but I like to spin the hole saws quit a bit slower than that and I don't have three phase. A simple phase-a-matic would be easy enough to get it running at 60hz but then I would have no speed control so a VFD makles more sense.

I started looking at VFD's and it's a crap shoot really. There are some excellent used units on Ebay etc. but you have to be really careful about the specs because some of them are very application specific and will have weird characteristics that make them hard to use.

I opted for the cheapest way I could see to get what I wanted. This item 1.5KW 2HP 7A 220VAC SINGLE PHASE VFD will take 220V single phase AC and spit out the same voltage in 3 phase. If your motor is not multi voltage this might be a problem because I believe the VFD's can only output the same voltage as they are fed. SO if you have a 380v or 460v motor that is not able to step down to 220/240 then this probably won't work for you.

The drill press is a 3hp but I have no real intention of using all 3 hp and I am sure I am violating all the laws of physics by only using a 2hp drive but it has worked fine for these 2 years of "hobby" level usage.

The connection is really simple for the "get running" portion. There is a hardwired extension cord from the double pole 15A breaker in the panel to the VFD. I ran regular 12ga extension cord with the ends cut off from the panel to the drill press. white/black connect to the double pole breaker and the green to ground buss. A 220v outlet will be added at a later date for this so I can move the drill press for cleaning etc. but so far I haven't needed it.
At the VFD the white/black connect to the input single phase power terminals and the green is doubled with the ground wire of the motor/controls to the ground terminal.

The motor is then wired for the correct voltage, there is usually a tag that shows the wire orientation. The motor then is connected to the output terminals of the VFD. All this is fairly simple in most cases but could be complicated by motor condition, availability of wire diagrams etc.

The controls portion is loads more complicated depending on control stations of the original tool. In my case I love electrical/electronics but have been to lazy in the 2.5 years I have had it running to actually wire in control buttons.
My controls are redundant for controlling the A/C voltage and so won't work correctly out of the box to wire into the VFD stop/start input so I just use the stop/start inc/dec on the VFD itself. One day I will wire in the controls, I want to keep the old controls and mount the VFD in a nema enclosure for dust filtering (there are numerous warnings about this on the VFD paperwork).

There are various settings required to setup for the motor settings and RPM ramp up/down but googling other forums and the chingrish manual I was able to get it running pretty quickly.

[icould]

Looks impressive and a heavy duty drill press for me! What brand is the drill-press from? Because I'm not able to see the name of brand on the machine!

[alwaysFlOoReD]

Take a look again; at the 4th pic.