18 wire 2 speed dual voltage motor puzzler
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  1. #1
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    Default 18 wire 2 speed dual voltage motor puzzler

    I have a 1980's Howa 17x60. It has a dual speed motor 3 phase (4 pole/8 pole); 7.5 hp at 4 pole, 3.75hp at 8 pole. The motor name plate says Fuji, but the rest of the data is mostly meaningless to the question at hand.

    It works great, but I need to change it from 240 to 480 to use VFD I have. I thought I'd seen most motor configs over my time, but this one is new to me.

    There's 18 leads coming from the motor. No switching of the leads is required to change speeds - just remove the voltage from one set of connection points and apply the same voltage on a different set, and it changes from 4 pole to 8 pole. Edit : AND short U1,V1,W1 when applied to U2, V2, W2. Rest left for context.

    The winding are arranged as 6 sets of 2 with the common point on each pair joined, hence 18 wires. All windings measure about 1.2 ohms so I assume they are all "the same"

    My first thought was "easy"; it's just two separate winding sets : one for 8 pole and the other for 4. Not so... and they are all interconnected at all times.

    I have drawn out the rats nest of connections and boiled it down two "interconnected" delta sets. Does anyone recognize this configuration and point me to examples I can see for 480v connections? It looks like I can maybe just change what looks like parallel deltas to series, but a lot of stuff has to go together "just right".

    Even better would be a lathe manual, but the electrical diagram of the stock manual does not cover the "optional" dual speed motor.

    Last edited by Lakeside53; 07-30-2016 at 12:18 AM.

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    There is enough typos or bad information here to keep anyone confused!

    2 phase motors do not connect as delta, they normally have 4 connection points, not 3.

    Normal 2 speed 3 phase dual voltage motors have 18 leads. Both Y connected and consequent pole motors.
    2 speed dual voltage delta connected motors need more than 18 leads.

    Some require the 3 leads that power is applied to for high speed to be shorted together for low speed. This type is called a consequent pole motor. Yours appears to be this type, but you do not note the shorting of the leads that are required for low speed.

    The other type that does not require the short is actually 2 independent windings, but you say that all windings are interconnected.

    "I have drawn out the rats nest of connections and boiled it down two "interconnected" delta sets." This does sound like the consequent pole motor for high speed. Using the other connection points and shorting the unused connection points cause the poles to be doubled and converts the 2 delta sets to basically 4 parallel Y sets.

    Clear as mud?

    Bill

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    I corrected the 2 phase to 3 - just a typo. Thank for catching that.

    Did you look at the diagram? I just put it "in-line" in case you missed it.


    Update : ha.. I did just find three hidden wires that short U1, V1 and W1 together when the high speed contactor is off and power is fed to V1, V2 and W2. That explains the speed change. I'll update the diagram above.

    Now... All I need to solve is the 480 conversion. It is possible according to the manual, but we'll see. Not obvious to me how to do it. I don't need the 8 pole config - just 4 pole.



    Here a redraw... but it's just to make clearer the connections.



    I be happy to just use the vfd with the motor as 4 pole; the 30hz performance will be the same as 8 poles. Now I just need to figure how to rearrange the windings for 480.

    Anyone want to comment about the below? Makes sense to me, but..
    Last edited by Lakeside53; 07-30-2016 at 01:52 AM.

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    Quote Originally Posted by Lakeside53 View Post
    It has a dual speed motor 3 phase (4 pole/8 pole); 7.5 hp at 4 pole, 3.75hp at 8 pole. The motor name plate says Fuji, but the rest of the data is mostly meaningless to the question at hand.

    It works great, but I need to change it from 240 to 480 to use VFD I have.

    All I need to solve is the 480 conversion. It is possible according to the manual, but we'll see. Not obvious to me how to do it.
    The motor tag should tell if it's possible, but you seem to feel that it is meaningless?

    Most 2 speed single winding motors are for a single voltage, if it's convertible the tag should state such.

    SAF Ω

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    Meaningless meaning it doesn't tell me how to convert it.

    You are right... but unless I take it out the I really can't reliably read the plate. I'm pretty sure it says 460/230. I was working from sketchy Howa info saying they were all convertible. I can only get a glimpse of the first couple of lines, and that is with two mirrors. I'll give it another try today.

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    In the IEC motor world, "dual voltage" motors will be 380/220, or 400/230, or maybe 415/240V all at 50Hz. The point is, the voltage ratio from low to high is 1.732, the square root of 3. In that IEC configuration, you connected the winding in Delta for the lower voltage, Wye (Star) for the higher voltage. Those types of motors will not be wound for 230/460V, which is a voltage ratio of 2:1.

    Now, technically if you WERE running it at 240V and it was fine, you SHOULD be able to run it at 480V, in fact that might even be better for it. So to connect it to a 480V source, use the Wye configurations in each speed.

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    Here is a scan from a Hardinge machine utilizing an 18 lead motor similar to yours.
    Insure that the shorted power leads are on the low speed. If they are on the high speed, there is another style motor that it is, different setup.

    Note that the power is applied to different leads on high voltage than it was on low voltage.

    Redrawing your diagram to be similar to this one, but with your lead labels makes it more useful.

    Is your current connection the same as what is shown, after you make the lead label changes? If not, we need to figure out why before proceeding.

    I would check current draw on each phase and speed on 240, reconnect for 480 but run it on 240. Check all 3 phases and both speeds again. Are currents 1/2 of the values before the reconnect? Are the 3 phases balanced as well as before? Does the motor run smoothly?

    If yes to all, try running on 480 and recheck.

    Bill
    Attached Thumbnails Attached Thumbnails 18wire2speed.jpg  

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    Thanks! I'm going to have to draw out what Hardinge is doing, but at least it's an 18 wire like mine. Yes, my "shorting" is of the low speed inputs (U1, V1, W1) when on high speed (input then applied to V2, U2, W2).

    I did manage to verify the motor name plate - it is 2.8kw/5/5kw, and 230/460. FLA are listed for each.
    In case anyone can help with motor data... Fuji Electric Co, Ltd, Type MRA1135A. Fuji is being unresponsive.

    Edit.....

    I've drawn out the Hardinge connections.

    Hardinge High volts : The Low and High speed configuration are the same I proposed below for 480v - series windings to make Delta for low speed, then flip power connection points and short low speed inputs to make parallel Wye for high speed.

    Hardinge Low volts : These are different to mine (2 x delta in parallel). For low speed Hardinge has two independent sets of parallel WYE (each leg with dual parallel windings), and for high speed the same but fed and arranged differently. I'm not seeing any obvious change between the high and low speed arrangements that made the consequent poles.

    I will take another good look at mine in a couple of days but I'm pretty sure it's connected as shown below for the 240 volts.

    I can post scan of the Hardinge interconnections if it would help.


    And I screwed up (grrr) the Low and High speed connection labels on the diagrams above. Too late to edit them and I probably messed up the original IMG tag with photobucket, so here they are again.

    Original 240v connections:



    Redrawn to show double delta arrangement :



    Proposed 480V arrangement :

    Last edited by Lakeside53; 08-01-2016 at 01:18 AM.

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    Just an update.

    I wired it for 480 as above but didn't like the "sound" of the motor running in 4 pole mode. Hard to pin down though so I measured the RST currents. In both high speed and low speed configuration I noted about 1 amp difference (low) on one connection so figured I'd messed something up.

    I reconnected it for 240 as per original and measured again... damn.... unbalanced current again. I isolated the "low" current to one set of coils. It "sounds" fine, works well but now I'm unsure if the motor has a problem that is masked by the parallel Low volts connection. I spent some time last Sunday measuring and detailing the process carefully. I'll get back with the data once I have time to document it and do some further testing. Work is a bit hectic right now. lol.. I'm supposed to be retired.

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    Hello,

    My name is Marian. I have a Harding DV-59 / DMS-59. 3 Phase 230/460 VAC Dual Speed 1750/550 Motor With 18 Wire connection. Currently its wired 460 VAC dual Speed. I was wondering if anybody can help me to wire this motor to a lower voltage of 230 VAC still dual speed. img_5567.jpgimg_5573.jpgimg_5574.jpgimg_5576.jpg


    I did see the wiring diagram for the 18 wire connection. But it looks like it not matching my currently wired 480 VAC. If any body has any idea of how to switch from 480 VAC to 230 VAC it would be greatly appreciated.


    Thank You
    -Marian Zieba

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    I don't know of any way to have a speed ratio of 3, so your motor has two completely separate windings.

    for low voltage your connection is the same as any 9 wire motor:
    line 1 to T1,7
    line 2 to T2,8
    line 3 to T3, 9
    T 4,5,6 shorted together

    add 9 to those numbers for the other set of windings.

    before you do this you can verify there is continuity between T 7,8 and 9 but nothing else
    continuity between T 16,17,18 but nothing else

    continuity between these wires and nothing else.
    T 1, 4
    T 2, 5
    T 3, 6
    T 10, 13
    T 11, 14
    T 12, 15

    its possible they have some other numbering scheme.

    edit: they skipped T 10 to avoid confusion. subtract 10 from the second set of windings.

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    Thank You Johansen for the quick response and for solving my puzzle on the 18 wire motor. I'm partially done. The first 9 wires are correct, but the second 9 wires i have continuity between T 17, 18, 19 and nothing else. There is no continuity between T 16. I don't have T 4, 5 and 6. Please can you verify that and show me exactly how i should connect the second 9 wires. Since I have T 11, 12, 13 coming from drum switch as the main power to those 9 wires. Can you show me which wire from the motor i should connect to each of the line coming from the drum switch.

    Or if you have a diagram of how to connect those wires. Should it be connect as Y or Delta.



    Thank You
    -Marian Zieba

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    continuity between 17,18,19 is correct, subtract 10 and you have 7 8 9 as in a regular 9 wire motor.

    16 should have continuity to 13 as should:
    T 12 to 15
    T 11 to 14


    correct 11,12,13 do go to the drum switch. subtract 10 and you have 1,2,3 as you would any other 9 wire motor.

    connect 17,18, 19 to the drum switch along with 11,12,13.

    14,15,16 get connected together, they are the new star or neutral point.


    how do you not have T 4,5,6? you have 18 wires right? T 4,5,6 need to be connected together for low voltage for the first set of windings (probably high speed)


    9-leads-star-high-volts.jpg


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