2 phase motor question

Discussion in 'General Electronics Chat' started by wcrenterprises, Dec 13, 2011.

  1. wcrenterprises

    Thread Starter New Member

    Dec 13, 2011
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    Hello, I was looking on the web for an answer to my question and came across this site, I'm sure there will be someone here who can help me with my questions and problem. I've done a fair amount of wiring but this job has really got me stumped as to what I need to do.
    I am in the process of wiring a Bridgeport milling machine with a J head, I believe it's a 1964 model. On the tag with the motor it says 1hp 2ph 60cy. 220/440, 3.26 & 1.63 amps. another tag says Induction Motor, type QZA, Frame 4570. The switch has a forward & reverse, there are 8 wires from the motor to the switch, 6 wires go to poles on the switch and 2 wires are hooked together with a green wire coming from them that appears to of been a ground but isn't hooked to anything at this time.
    My problem is I don't understand the 2 phase, I've never heard this, only single and 3 phase. I would like your impute as to wiring this machine, do I use 220 single or 3 phase, or ? This is just for my own personal use, the days of long hard work for this machine are done while I have it.
    Also I'd like your impute as to what I need for wire, it's 50' from the breaker panel to the machine, do I use 12/3 w/g, 10/3 w/g or ?
    Also I have a 5hp converter for 3 phase for my lathe but if I don't have to use it for the mill, I'd just as soon not, I've read where 3 phase is better for reversing the motor but again I'm not familiar with that, I'd like someones impute on that also, I'll do what I need to do.
    Thanks,
    Wayne
     
  2. BillB3857

    Senior Member

    Feb 28, 2009
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  3. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Never saw a Bridgeport with a 2phase motor. Where are you located? A town in New York state and Chicago area did have 2 phase but that was a while ago.

    Most 2phase is four wire, so the switch would have eight poles for forward and reverse, not six. Six wires plus ground sounds more like 3phase.

    Like BillB said, post a photo of the name plate.
     
  4. wcrenterprises

    Thread Starter New Member

    Dec 13, 2011
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    Thanks guys for the info so far, in my reading, I read that a 2 phase motor will have 2 sets of windings so I pulled the cover off my motor and there is only 1 so now what? was it replaced at some point and the tag not replaced???? I'm hoping.
    I will snap a picture of the tag but will someone tell me how to post it? It says just what I posted in my first post. There is also a diagram of the wiring for 220 & 440 volt, it says Design-R, 220, then under that, Two Phase Connected and 2 diagrams, each with 8 wires.
    I'm in NC but the machine came from NJ so God only knows if it came from the Buffalo/Niagara Falls area where 2 phase was used.
    Looking at the forward-off-reverse switch, there are only 3 places for wires to be hooked up, not the 4 needed for 2 phase as I understand it.
     
  5. strantor

    AAC Fanatic!

    Oct 3, 2010
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    sounds like a capacitor run single phase reversible motor to me. I just hooke one up not too long ago. 6 wires come out. you make 2 pairs, depending on voltage, so that leaves you with 4 ends (2 single wire ends and 2 paired wire ends) and these 4 ends need to go to a reversing switch.

    the only reason for bringing 6 wires out on a 3phase motor is to switch star/delta, which doesn't make sense being wired into a reversing switch

    are you sure it said 2PH and not just 2P? 2P = 2 poles
     
  6. wcrenterprises

    Thread Starter New Member

    Dec 13, 2011
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    I wished I knew how to post a picture, there are jumper wires soldered from one side(forward) to the other side (reverse) and in the middle are the 3 screws in a row to hook the feed wires.
     
  7. wcrenterprises

    Thread Starter New Member

    Dec 13, 2011
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    It says 2PH, no doubt in my mind.
     
  8. strantor

    AAC Fanatic!

    Oct 3, 2010
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    well, :
    http://forum.allaboutcircuits.com/showthread.php?t=62569&page=2
    I could see how, if this were a single phase capacitor run motor as I suspected, they could justify calling it a "2 phase", especially since all the windings come out with leads.

    How to upload a picture:
    1. don't use the "quick reply" box at the bottom, click the actual "reply to topic" button, or click the "go advanced" button.
    2. you will go to a dedicated reply page with many more options. right under the reply box, you will see "advanced options", and within that box, you will see a button "manage attachments" - click it.
    3. The box that pops up should be pretty self explanatory, just browse, then click upload. observe file size limits listed, or your pic will not upload.
     
  9. strantor

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    OP sent me a drawing of his switch. pretty obviously 3phase to me now. the incoming would connect to the center posts on the switch. any objections?
     
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  10. strantor

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    Oct 3, 2010
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    OP sent some pics to my email; I think he's having trouble uploading. It's officially 2 phase, the likes of which I have never seen before, and I have no idea about the switch.

    It's made by fairbanks morse, which as I know them, made a bunch of wacky stuff. They made the opposing piston diesel engine that goes in los angeles class submarines, the ND 8 1/8. I would expect some wacky 2 phase nonsense from a company that puts a fraction in their model numbers.
     
  11. strantor

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  12. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Checked the Bridgeport manual I have and doesn't mention 2phase motors. So when to Practical Machinist and found these -

    http://www.practicalmachinist.com/v...fd/single-phase-two-phase-three-phase-158678/

    http://www.practicalmachinist.com/vb/transformers-phase-converters-vfd/2-phase-converter-103376/

    Hope it helps. Seems like 2phase was still being used in the Buffalo/Niagara Falls, NY/Niagara Falls, Ont and Philadelphia/Camden/Reading areas until the 1960s.

    http://www.practicalmachinist.com is a good place for Bridgeport information and all things having to do with machine tools.
     
  13. wcrenterprises

    Thread Starter New Member

    Dec 13, 2011
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    Thanks for all the help with this bugger, I really appreciate all your efforts. I have one more question, do you think, $ wise I should just go ahead and try to find a replacement motor? if so 220 single phase?
     
  14. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Personally I would change the motor.

    About 15 years ago a guy I worked with bought a Bridgeport with no motor. It was the step pulley type. A new Bridgeport motor was very expensive.

    I talked him into making an adapter plate. Laid out the shape and size of the original motor, they are not of a standard/popular frame type, on a piece of 3/8" steel plate. Then machined a hole and bolt circle to fit a face mount motor like this -
    http://www.surpluscenter.com/item.asp?item=10-2374&catname=electric

    Haven't seen him for a few years, since retiring but it was still working fine when I retired. The motor he used was actually from an old swimming pool pump he already had. This idea does work and is much cheaper than a replacement Bridgeport motor.
     
  15. wcrenterprises

    Thread Starter New Member

    Dec 13, 2011
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    Thanks once again, fabricating something to fit won't be a problem as 50% of my time at work was welding/fabricating. I believe that's the avenue I'm going to take.
    This machine came from Cherry Hill, NJ which is real close to Philadelphia, it might explain why it is 2 phase. However, it is one more lesson in life, I was told it was 220 volts,3 phase by the seller so I wasn't concerned with what the tag said.
    I still wonder about the 2PH having 2 sets of windings, I did a image search for 2 PH motor windings and there are a couple motors with 2 sets of stators & windings, but they looked like large motors. Is it possible for the same stator plate to incorporate 2 sets of windings, like every other coil being for 1 set? Hope you follow what I'm asking. The coils on this stator are small and close together, would the armature turn fast enough so it would work? If I'm all wet with my thoughts don't be afraid to tell me so as I'm NOT an electrician.
    Thanks again
     
  16. shortbus

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    Thats basically what a 2phase winding is, two sets of coils. One set for each phase.
    3phase has three sets of coils. Thats a real simplified view of it, but thats how it works.
     
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  17. PackratKing

    Well-Known Member

    Jul 13, 2008
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    OK......retired "novice" here........stop confusing me !!! :p

    I was under the impression that a normal household 240 volt power feed - connecting to two bus-bars in the AC Panel, are 180 ° apart, which in theory/practice could be called 2-phase for a 240 volt motor.

    I like my old 1 1/2 Hp 220 v. monster running the air comp. Repulsion start, w/ brushes and commutator instead of a switch. Thing starts like 3-phase.
     
  18. shortbus

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    2phase is 90° apart, unlike the single phase. Thats what allows the 2phase motor to start without a start winding. The only or one of the reasons that 3phase won out over 2phase is that 2phase takes more wire. Since there is no neutral in 2phase it takes four wires plus ground. Where 3phase takes three wires plus ground. And 2phase is two separate currents of a single voltage. Where single phase because of the 180° separation can have a lower voltage and a higher voltage from one line. Like single phase 240 - 120 or 440 - 220.
     
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  19. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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    1964 seems kind of recent for implementing that type of motor, but it could have been a retrofit or specific request for an exsisting facility. 2 phase preceded 3 phase as a utility service, but that was many moons ago. If you have 3 phase available, you could do some research on a Scott T or Scott connection to obtain your phasing. Personally, I'd switch it out to single, or better yet, 3 phase.
     
  20. wcrenterprises

    Thread Starter New Member

    Dec 13, 2011
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    This operation is just for my own personal use more or less just playing, I have a 5hp phase converter for my lathe which is 3 phase the reason I think I'm going to switch the motor on the bridgeport to 220 single is so I don't have to have the converter running. It would just be nice to just turn the mill on if I want to do some milling. If I planned to run the mill real frequent I'd go with the 3 phase.

    Can anybody tell me how large the transformer or what ever it consist of is on the Scot T system? meaning would it have to go on a telephone poll or would it be something that just mounts to the wall by the electric panel ? Thanks
     
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