Bridgeport 3 phase to single phase

Hello all,
I have been reading the older threads concerning this topic. I am aware
that I can go the phase converter route and the other suggestions that
people have made. But, my situation is a bit different. My motor is a
2hp, 3 phase, 600 volt, on a 2J variable speed type mill. I can get a
phase coverter and a step-up transformer to make it work, but at
considerable expense. I am just wondering if anybody has actually
converted their mill to a 2hp single phase and can tell me which motor
I need to buy.
Thanks for your ideas,
Todd
Reply to
toddbest
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I don't think much of your economic decision. You'll lose the ability to plug reverse the machine, which, to the uninitiated, may illicit a "so what?" response. Only when you understand the proper operation of a drop spindle mill will that have any value for you, then it's too late.
Spend your money getting the three phase service via a rotary phase converter, not replacing the motor. That's a decision you won't regret. Ebay can be your friend in this instance-----watch for a 3 phase step-up transformer.
Harold
Reply to
Harold and Susan Vordos
If he's going to do a rotary converter he would be better off either stepping up the voltage with a less expensive single phase transformer before the converter and using a cheap-because-nobody-wants-it surplus 600v 3ph motor in the converter, or by replacing the 600v 3ph motor with 220v 3ph motor and staying low voltage.
Pete C.
Reply to
Pete C.
Yep! I agree.
Harold
Reply to
Harold and Susan Vordos
Buy the appropriate C-frame motor, and make a switch mount and a motor mounting ring and wire it up. Look at your existing motor and make sure you get a replacement that has the same shaft size, as you'll be swapping the pulley old/new.
GWE
Reply to
Grant Erwin
I'm be surprised if you couldn't find a used 3 phase motor and a capacitor only phase converter for less than a 2 hp single phase motor. A single phase motor will not instant reverse like a three phase motor will, even if the three phase motor is run from one of the above mentioned phase converters. ERS
Reply to
Eric R Snow
Todd, If your ok with losing reverse..... I dont see why you can't convert it to 230V single phase. I might be able to help you get a single phase motor for it. There is a Frame designation on your existing motor is it 145TY-4 ??? Also verify the RPM printed on the label it sould something like 1750 or 1800. If its diffrent let me know. I should have a line on what you need for it. Keep in mind that a 2HP single phase motor might not have the muscle of the 3ph, however if your an average user you'll never know the difference.
If loosing reverse is a serious problem, (it would be for me) youll need to rewire, rewind (a good motor guy can do that), or buy a 3ph 230V motor for it. I can also help you with a drive that will take in single phase 230v and output 3ph. It is not rotary - all electronic. virtually silent.
Ryan snipped-for-privacy@cruisecontroltools.com
Reply to
Ryan
Note that if you want to plug reverse a motor running inertial loads (all those pulleys and spindles), you may need to size the phase converter more conservatively (ie get a bigger one).
i
Reply to
Ignoramus14487
I would think having reverse is absolutely essential - can't use low range and standard tools without it...
Reply to
Stephen Young
[ ... ]
I think what he was talking about is the ability to "plug" reverse. That is, just switch the windings while it is running forwards, and suddenly it is running in reverse.
You can't do this with the typical capacitor start single-phase motor, in part because the speed of the motor will keep the start winding from ever engaging until you coast down to almost a dead stop. Just throw the switch to reverse, and it will keep going forwards at full speed.
And plug reversing is important when you are doing tapping with the mill. Skip that, and you break off a tap in the bottom of the hole. (Well ... if you have a tapping head like the TapMatic ones, the reversing is built into the mechanics of the head, but for "rigid tapping", you have problems.)
Personally, I have gone the VFD route, though I started with a 230/460V motor, not a 600V one. But the advice to pick up a 230/460V Bridgeport motor and swap it into the head is the right way to go, I believe.
Enjoy, DoN.
Reply to
DoN. Nichols
Very much true. Not to mention losing the ability to tap quickly and easily.
Gunner
"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3
Reply to
Gunner
Hi
I take it fro your voltage, that you are in Canada. What I did in my shop is buy a 7500va 220-600V single phase transformer and hook up a VHD to my mill, my drill press etc. None of the VFDs i used were rated for single phase but three of the four that I bought worked. I have an AB 1333, an AC Tech and a Hitatchi j100. I have also mounted a single phase motor on a Bridgport but this is not that easy. If you are in Southern Ontario I can help you find a used transformer and VHD. I think you could get a transformer for $150 and a VHD for about $150.
Reply to
sbaer
Hi,
Your right that I am in Canada. But, down east in Nova Scotia. The checking around that I have done I have found that there isn't a direct replacement for the 2hp 3ph. The way you have done it sounds like the way to go. If you can provide me with some names/numbers on where to start looking for what I need, it would be a big help. Also is it straight forward on the hook-up of all the required systems? I have been a machinist for 20 years and I'm also pretty good with electrical systems so I understand the tech talk.
Thanks, Todd
Reply to
Bluesman
3-phase motors go very cheaply on Ebay. VFDs can be gotten on ebay as well, or Dealers Electric. The whole conversion with motor and VFD should cost about $300 from these or other surplus sources. There was also a recent post re cheap Teco VFD prices.
Reply to
lens

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