View Full Version : 440 Lathe to 220?

12-14-2011, 11:29 PM
I've been following Hotrod32's thread on his Bridgeport cnc mill. I'm about as electronically challenged as Hotrod and I think my problem May?? be easier and I could sure use some help getting this thing up and running. I bought a rather large lathe with a 10 hp motor. It's wired for 440. It also has a coolant pump and I assume it is also wired for 440. Both motors are 220/440. The main problem will be with the contactors and overload relays. It was suggested that I would need a transformer so the lathe could run on 440. That seems to me like driving a tack with a sledge hammer. The lathe was made in Tiwan? in about 1985. I'm wondering if the contactors and overloads could be modified? If not, how about replacing them? I was really stretching my skill set when I was able to hook a VFD up to my Lennox nibbler and get it running. I would sure appreciate any help. I'll try to post some pictures. Thanks Norm

12-15-2011, 04:31 AM

You are a mile ahead, you need to swap the "control" voltage transformer taps there to 220.. I suppose you don't have 3 phase.. so the coils on it need to be on the single phase power and not the phase generated leg.

Since all the controls run off the 120 volt secondary on the control transformer there is nothing to swap there, (sometimes they have line voltage contactor coils in them relays)

1: Heater coils on them motor contactors. They are set up to "heat up and trip" at a watt-loading, ie: 440 @ 3 amps is the same watts as 220 at 6 amps.. (volts x current = watts) BUT, with a slightly imbalanced phase generator that is all changed slightly and they will probably trip out.

2: inside the motor tap-boxes.. peckerhead, con-box where the feed comes in? You'll need some pictures of that.. where you will find probably Lil copper strips to change the internal winding connections to the 220 connections. I didn't see a picture.. but.. I have not finished my coffee yet either.. Lemme drink a cup and I'll look some more.

Home-made phase generator,
I use a 10hp motor here to generate 3phase for my 5hp hyd press.. I spin it up to speed with a 120 volt washing machine motor then slam 220 single phase on two legs.. take the 3rd leg off to the other three phase devices here.. NO expensive phase convertor, no refrigerator relays, nothing.. It works, thou the phase generator makes some growling as it idles.. it works.
The more 3 phase motors you have running, they "back feed each other".

If I was local, that is about a Steak dinner's worth of conversion there. you are lucky, just take your time. There are more electricians here than me also.. so.. anyone else that wants to back up my half blind-forgetful self can wade on in..

12-15-2011, 07:57 AM
Well Norm welcome to the world of the electrically confused!!! :confused:

I'm still plugging away at mine and dieing to find out if I can get the motor to turn. Cold weather and no real heat in the garage is slowing me down now among other things. Young fellow down the street was sanding away on something so I went to see what he was up to.

Ended up loaning him some hammers and dollies and the like and trying to show him a few things about metal bumping. I'm hoping it cut down on the mud he used over all.

So I'm going to see about changing out the fuses on the bridgeport and get that done. I still haven't found them "heaters" to even go about replacing them. Its not as much fun now working on a 1 ton chunk of cold electrical confusion!!! :lol:

12-15-2011, 10:08 AM
The control circuits are on the 110V side of the transformer and only 1phase. Just rewire the transformer. You now have a short wire H2-H3. Move one end so it goes H2-H5. Then make another short wire H1-H3. Now the lathe should start and run, but the motor will be very weak so do it just for a test, no cutting.

Then you will have to rewire the motors. Usually there are 6 connections wit some shorting bars inside the motor connection box. You have to move these shorting bars to make it run in delta configuration instead of wye. Put up some pictures of these. Check inside the connection box, often the instructions are there.

If you don't have 3phase you have to take care of that first. David knows how to. I have always had 3 phase, even in my summer house. :)

12-15-2011, 04:10 PM
Yah, I'd figured that out, but didn't want to plunge into something and then forget what I'd done or hadn't done. It's age related. On the fuses under that transformer, there is some clear plastic-like leakage (see new pictures). Is that bad?
1) This is the one I'm completely in the dark about. If they trip what then? (I was going to ask pointed questions but was afraid you would think I know more than I do). All I think I know was gleaned from a FactoryMation catalog.
2) Motor tap boxes (see new pictures). This is the one for the 10 hp motor. The strips are in the bottom of the box. Never done one like this. Most are bolting wires together. The pump motor is still buried deep in the gut of this thing, but I'm sure it can be changed too (see picture).

Phase converter? Glad you asked. I bought a used one but i've never installed it, but have started (see new pictures). It's suppose to be good, but aren't they all. I'm into it $250 with the 15 hp idler motor. I also have two other 15 hp motors to try if this one is no good. The reason I haven't completed the installation? Don't know what I'm doing and afraid to cause darkness through-out the state.

12-15-2011, 04:25 PM
Like your mill. I have a 1 hp Bridgeport. Like my lathe its been sitting waiting for it's home to be completed. I'd really like to have both going by the first. What a way to start the new year. Can't believe the collective knowledge and the sharing that goes on on this site. I know a little bit about a few things. I just hope I will be able to pay back. Norm

12-15-2011, 04:32 PM
Thanks for the input. I've posted a few more pictures that show what you were asking. Are you seeing anything else that will pop or fry if I put power to it. What is that clear plastic thing in the later pictures? Again thank you all for your help. Norm

12-16-2011, 03:13 AM

No clue why anyone would "glue" a set of fuses in??

That clear plastic thing is a relay, from the looks of it, a 2 pole 8 pin relay that plugs into a black base.. there is a indexing point on a round socket there under it where it plugs in, you can pull it out, it will only plug in one way, (sometimes installed upside down) with the index down, the lower outside terminals are the coil inside, the inside two on bottom are the common relay contacts, the top outsides are Normally open contacts that pull in with the coil, the inside top two are Normally closed contacts that open when the coil energizes.. Being two contacts in relay, the left is isolated from the right.

I've wired a million of them, used to be control logic didn't come out of a computer but relay logic. These days things have became complicated.

No clue about the phase generator you have there.. I'd find the instructions that came with it and go from there.. the capacitor bank in it, that "smooths" the phases generated and moves the "pulses" to a location where it can run.. I'd still run a idling motor to further smooth it out. You got a expensive box there. I did a breaker panel like that once here with a "3rd" phase terminal strip to connect the machines.. I took the breaker 2 pole and a unfused 3rd leg out to each machine where they had a switch and overloads there. It has gotten much simpler here now, I got a twistlock plug and extension cable for the inverter and the phase generator.

Retapping the motor.
The lil links, wires in the motors have to be all pulled loose and connected there as shown, stacked and linked to make the "connected" diagram.. You maybe needing more links than you have there. There are "markings" next to the screws I can't see from Georgia. AND you are right, most the motors here in America just "tap" wires together there.
Sounds like you are "more knowledgeable than average" and I have confidence you can figure it out.

Heck, what do I know? it is 4am, I got up and the bulldog took my warm spot in bed.. He's worse than a big kid. I'm making coffee..

12-16-2011, 03:37 AM
Lucky you?? them overloads under the contactors have "adjustable" trip on them... the red screw on the right hand side can adjust it. Those might work as is.. or adjusted up slightly.

Normally "here in USA" it is a coil of wire heating up a thermal switch (why they are called heaters) , or a link with a gear (square D) that liquifies-melts when the wattage is exceeded and allows the gear to turn and trips out then re-solidifies when cooled off. The purpose of motor overloads is to "protect" the windings in the motor from excessive amperage-heat and premature burn-out.

A big lathe like that? if you are loading that motor up making cuts.. shame on you.. I had a 24" lathe here for a while, It shook the building as it ran. I turned a few Harley solid mags.. but never used it much.

12-16-2011, 08:13 AM
I cannot see that picture 1 and 2 belong together?

If the motor runs as it is in pic.2 I don't know. Those I know would not.
If I can assume the 3 links lying in the bottom were shorting out the 3 uppermost screw posts that would be the 380V configuration here. (Shorting U2-V2-W2 together) To make a 220V configuration the links should be placed vertically. (Shorting U1-V2, V1-W2 and W1 to U2 or any other shorting <Letter 1> to <Letter 2> where the letters are different for each short. And doing this on 3 places.) The above may be misleading, as things may be different as we're almost half a globe apart. But the next paragraph is universal.

And don't be afraid of making Oregon go in black over the holidays. :p That's why there are lots of circuit breakers between you and Oregon's main power source. You may have to reset one or more within your own house though. It seems you know how to sort volts from amps, so I'm sure you'll figure out where those breakers are.

12-16-2011, 09:54 AM
The combination of links and wires, next to the studs in the motor are lil circles with "legends" ie: U, V, W, Are cast in the ceramic insulator. You'll have to move the wires to read them.

The 220 hook up.. Combine incoming wires, Motor wires, labeled studs, copper strips to connect as follows.
Common on Phase A from overload, U1,U2,Z1,Z2
Common on Phase B from overload, X1,X2,V1,V2
Common on Phase C from overload, W1,W2,Y1,Y2

if it runs backwards to buttons, swap the motor wires there on the overloads. Swapping any two main phase wires in a 3 phase motor, will reverse rotation. IN a Paper mill, I've rehooked up whole buildings only to find out the whole plant is reversed. swapped the leads on the transformer and all was well, changed directions in all the motors at once.

That lil control voltage transformer??
one 220 line to H1 and H3
One 220 line to H2 and H5
May have to make a pair of jumpers.. Do not use the "generated" phase on the transformer.. a generated phase is not "voltage stable" and will give random results.. possibly burning out the transformer.. OK??

Not sure about the coolant motor? Turning radioactive materiels it needs it, magnesium? lemme see.. (heck no, not here at my shop)...

12-17-2011, 10:44 AM
The motor wire box and the four "star" picture are the same. The "stars" are the schematics for the various ways the motor can be wired. dawai (david?) is right on that. I'm going to rewire the big motor and the transformer today. At least I can get that far. I'm starting to see the light at the end of the tunnel.

12-17-2011, 11:24 PM
Here is a picture of the jumpers installed on the transformer. That "glue" on the fuses may be epoxy that has leaked from the transformer. Is that a problem? The "coolant pump" is actually the oil pump for the headstock (what was I thinking) and it's really buried. It's almost impossible to access the motor wiring. I'll try again. Norm

12-17-2011, 11:44 PM

If it is a "oiling" motor pump instead of a coolant pump, it is needed huh? It may run on 440 wiring at reduced power. It may stall out by having less than half power. Wired as it is at 440 connection it will not burn out from too much amperage. It may overheat thou from stalling out without enough hp.

You are learning "chinglish". Converting Chinese manual into American English, sometimes I think they do that crap on purpose. About all the 3 in 1 tools I have saw have the manual "incorrect" showing the wiring of the head stock motor. I had one, never doubted the manual. The 120 volt and 220 volt diagrams were reversed. I cursed that thing everytime a drill or cutting tool would stall out the under powered motor.. Little did I ever "think" that it was tapped wrong. It was tapped like the directions said, I checked. The crappy motor would never reach "full power and heat" thou and would last a long time huh?? I only realized this much after selling the tool helping someone rewire one all the "switches" were gone from.

We, can only follow directions so far. If you are fed bad information it normally ends poorly. Like Einar said, we are a half a world away from each other. Somewhere a engineer is propping his feet up on a desk smiling at all of us.

12-19-2011, 10:48 PM
This is a picture of the oil pump. It's buried 10 inches down a 6 X 10 tunnel in the guts of this thing. The adventure continues. I can't read the numbers or count the leads.... yet. Any guesses as to how it's wired? (note the three leads tied together with a bar). Thanks for all the help. Norm

12-20-2011, 04:22 AM
I am assuming it is "star" tapped, of the two voltages on the legend plate, it will be the higher labeled one, since the resistance is "higher" to limit current through the windings.

(when you assume, you make a " ass of u and me ") Can you "find someone else with a lathe like yours, possibly on Home shop machinist or another machining forum?? and beg for a real big favor.. of a picture otherwise, you need to go purchase a "camera snake" to send down the tube and read the wires, then get some very long tools to work down the tube.. or ... try it at the higher voltage, and if it burns out then you can tear it all apart for a rewind.. (what most hired electricians would do, since they don't own it) They'd be paid and long gone and not answer any more phone calls..

Harbor freights model.. called a digital inspection camera, currently $89... or there is always a dental mirror taped to a stick and a flash light.. and some contortionist training videos. (Most electricians stand on their heads anyways>>??)

12-20-2011, 10:21 AM
(note the three leads tied together with a bar).

I bet there are 3 shorting bars on the right side even if only 2 would do the job. Use these to short right/left instead.

It's like this now:

( The dots are there just to place the "|" shorting bar in the right position.)

You want them like this:



12-20-2011, 10:41 AM
You're great!!! I bought one of those from HF about a year ago (with discount and coupon). I've used it 3 or 4 times reading stuff on this project alone and it's more than paid for itself. Need to make a bracket for the wand to make it work though. I'm thinking the pump motor is a 9 wire and the big motor is a 12 wire. I've never run into a twelve wire. (not suprising given my very limited experience). I can find no schematic for the pump motor and will have to get the wires loose to see how they're marked. It's neat, even as you grow older you learn new stuff. Thanks for all your help. Norm

12-20-2011, 10:52 AM
I think I see what you're saying. There are three bars a stacked all stacked on the right side. I the final wiring they will be in three positions horizontally, tieing the wires together???? Thanks I didn't see the stack. I'll get it apart and report. Thanks. Norm

12-20-2011, 12:02 PM
Einar "sounds right".. I'd look at the wire markers and the terminal post markings just cause that motor would be hard to replace.

Mostly we have "wire tapped 9 lead motors here in the USA". 12 lead motors are odd.. saw more than one or two hooked up wrong by seasoned electricians here. the ones with the terminals and bars to make internal connections really confuse a lot of USA electricians..

(I stay confused) Recently I helped some guys out with a old "wye-start delta-run" 100 hp motor.. The motor was burned out and we sent it out to be rewound, they rewound it as a 3 lead motor.. and I spent a half hour on the phone trying to explain to the young guy why it would not work. (cause everyone's lights would blink with across the line starting)

You have of course missed out on some "great home made chicken and dumplings, some Home made cornbread" and now I need a nap...

I think you got this whipped..

01-01-2012, 05:56 PM
Well I finally got to the pump motor. I was able to pull the leads loose from the terminal block and read the numbers on the wires. the leads read one though six. The input leads are wired to leads one, two and three. Leads four, five and six are "wired" together with the three two hole brass bars. If I read Einar right I should "pair up" one and four, two and five, and three and six and then wire each one of these pairs to an input lead. Is that correct? Man this thing is tough. using only one hand and using mirrors and flashlights. Thanks for all the help. Norm