NON WORKING EXCITER. I need some info 10ee 1945 MG
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    Default NON WORKING EXCITER. I need some info 10ee 1945 MG

    my 10ee exciter arrived with a non working exciter

    I am trying to get it working. It seems like it was not wired according to the schematic and the replacement brushes were never seated.

    I have a few questions.

    1. there is a variable resistor in series with the shunt field. where should the resistor physically be located?
    mine was bolted to the outside of the exciter casing with the wires running through the opening.
    it didn't look like that was the factory mounting location
    should it be mounted inside the exciter?
    More importantly to how many ohms should the resistor be set?
    i think mine goes from zero to 200 ohms.
    2.it looks like there where replacement brushes that were never seated
    the replacement brushes did not have a wire connected to the back. it looks like the wire had been removed
    and they were relying on the spring for connectivity
    should i rely on the spring or solder a wire on there?

    3. it looks like both the series field and the shunt field are wound around the same core
    so on both sides on the exciter there is a winding. each winding has two wires coming out of each side.
    there is a heavier gauge wire and a lighter gauge wire.
    i am trying to figure which wire goes to which field
    i assume that the heavier wire is the series field and the lighter wire is the shunt field
    can anyone confirm which wire is for which field?

    Thanks in advance
    Rich

    here you can see how my resistor is mounted
    fd65c0ea-81f5-4a85-84f2-40d16e3cb073.jpg

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    Here is a very good discussion about the exciter:
    From the sticky's above: 10EE - No Exciter Voltage

    The original location for the resistor is in the bell of the generator, just below the exciter. I believe that the resistor is mounted in the generator bell because there is cooling circulation through the generator and AC motor driving the generators.

    In the 'Sticky' discussion, Cal spells out the normal ohm readings and procedure.

    DualValve

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    Above link is VERY helpful. I’ve had to refer to it more than once. On mine, I finally took the exciter apart and turned the commutator down past burns/divots. Carefully filed the mica and seated the brushes, and now is working great.

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    i got the exciter WORKING! HOW EXCITING!

    I seated the brushes and I had to rewire it. previous owner wired it wrong.
    I mounted the resistor right above the sheave in the front of the exciter

    right now it is sitting on my bench. but i got it spinning close to operating speed maybe 3k rpm and it was producing 101v dc.
    tomorrow i will mount it in machine and tweak it
    thanks for your assistance
    Rich

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    i got the exciter mounted but it is only producing 105v dc. variable resistor is at its lowest setting of about 2.5ohms.

    i had some trouble starting the spindle at the highest RPM 2500.

    machine ran better with the 115vdc power supply.

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    That's definitely not the original resistor. Take it out of the circuit and see if the voltage improves.

    The problem starting at 2500 RPM is because your FA relay isn't working.

    Cal

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    i shorted the resistor and the voltage actually went down to 102vdc from 105
    i also manually pressed the FA relay and spindle still did not start

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    I wouldn't expect the voltage to go down when you jumper around the resistor. You might check the field current.

    I assume that you checked the resistances of the windings.

    It's possible that the brushes aren't correctly timed. Look at the brush ring and see if you can find the index mark, then look for a witness mark on the hub of the spider. Later model exciters have the index mark at about 9 O'clock, when looking at the pulley end of the exciter:

    img_9933.jpg


    Cal

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    Quote Originally Posted by Cal Haines View Post
    It's possible that the brushes aren't correctly timed. Look at the brush ring and see if you can find the index mark, then look for a witness mark on the hub of the spider. Later model exciters have the index mark at about 9 O'clock, when looking at the pulley end of the exciter:
    There's a good possibility!

    In our phone chat earlier this evening suggested digging PM's Monarch forum archives as to whether the field needed "flashed" as well, and if the now "liberated" DC bench supply was useful in doing that, if so.

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    I have information about flashing the exciter in this thread: 10EE - No Exciter Voltage Give it a try if changing the brush timing doesn't increase the output. Might be some other brush issue as well, perhaps one of the brushes isn't well seated.

    Cal

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    I seated both brushes. they were never seated. i assume that is why the exciter wasn't working when i got the machine. i also had to redo all the internal connections.
    is it possible i made a mistake with the polarity of the field windings that is causing the low voltage?

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    Quote Originally Posted by lectrician1 View Post
    I seated both brushes. they were never seated. i assume that is why the exciter wasn't working when i got the machine. i also had to redo all the internal connections.
    is it possible i made a mistake with the polarity of the field windings that is causing the low voltage?
    Possible, yes.

    If reversed from OEM, the timing could be working contra instead of pro.

    The magnitude seems to be about in the right range, too.

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    Default exciter VS power supply

    another weird thing. with the dc power supply, the lathe would run/start flawlessly at all speeds even if the supply was as low as 90v dc.
    Now with the exciter at 105v, the spindle has trouble starting at 2500rpm. When trying to start at 2500 rpm, the gen would sound taxed, for a second then the forward contactor drops out. another second and the contactor pulls in and the gen try's to start then the contactor falls out again. this keeps happening. on off on off.
    happens worse when in reverse

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    i had to guess about the internal connections and which wires went to which windings and the polarity.
    i saw in an old post that the armature connection to the series winding had to be on the right side brush when looking from the front.
    i saw the post after i installed everything and i am not sure i did it that way.

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    Quote Originally Posted by lectrician1 View Post
    another weird thing. with the dc power supply, the lathe would run/start flawlessly at all speeds even if the supply was as low as 90v dc.
    Now with the exciter at 105v, the spindle has trouble starting at 2500rpm. When trying to start at 2500 rpm, the gen would sound taxed, for a second then the forward contactor drops out. another second and the contactor pulls in and the gen try's to start then the contactor falls out again. this keeps happening. on off on off.
    happens worse when in reverse
    Does that only happen at high RPMs? If so, it sounds like the exciter voltage is dropping enough that the contactor is opening. If it's now happening at all speeds, it's an issue with the hold in circuit.

    Cal

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    Quote Originally Posted by lectrician1 View Post
    i had to guess about the internal connections and which wires went to which windings and the polarity.
    i saw in an old post that the armature connection to the series winding had to be on the right side brush when looking from the front.
    i saw the post after i installed everything and i am not sure i did it that way.
    Ah.. hard to not come across as snarky, but surely you don't expect one of we chikn's out here in PM land to remember which way? AFAIK, we weren't even in the room?



    I'd flash just because you can, check the polarity, set the timing - confirmed by actual output, not just to the mark, see what happens.

    You don't have full voltage, you don't have full current, at least one Rheostat is imperfect.

    - FA relay is wonky - there's your poor start at 2500 RPM. Hardly any Field with the Rheostat current-limiting what is already short-rations.

    And we are still not 100% certain there isn't some other fault still hidden.

    Dig that thread Cal posted. Good info there AND in the links as branch off of it.

    See the wiring there.

    You've mentioned some re-wiring on your machine. It is important that OTHER things - contactor actuation coils , for example - see the full power from the Exciter, not what is left AFTER the Rheostats have done their job of current-limiting it for the variable fields.

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    it only drops out at the highest rpm starts

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    Quote Originally Posted by lectrician1 View Post
    it only drops out at the highest rpm starts
    Of course. As stated - the Field is only weakened above base RPM.
    EG: Anything above 670 RPM (at the motor..) for the large-frame Reliance 3 HP.

    Similar effect to trying to pull off the line in a motor vehicle in overdrive fifth gear.

    The FA relay is equivalent to an automatic-transmission's downshift. Close parallel, MOPAR Powerflite 2-speed. Kicks down for passing as well.

    Just as the FA acts for rapid change of speed, not just starting.

    WHEN.. it is working. Otherwise, NOT. Same effect as dropping the clutch in fifth gear. Tries to stall the motor.

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    The exciter is designed to put out a constant 115 VDC at varying loads. The series field, in series (as the name implies) with the exciter's armature, increases the field and therefore the output of the exciter when the load increases. The shunt field, which has the adjustable series resistor, must operate in opposition to the series field. As the voltage increases, current through the shunt field increases, opposing the series field and DECREASING the exciter's output to keep the voltage where it belongs. That's is why a jumper across the resistor, which increases the series field current, DECREASED the exciter's output. Try increasing the series resistance.

    Also note that if the polarity of the shunt and series fields aren't correct, they will work to push the output voltage in wrong direction as load changes. You say you guessed at how to connect the leads; how many leads are we talking about?

    Cal

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    there are 8wires altogether.
    one winding on either side of the armature
    two wires coming out of each side of each winding.

    so each winding has two wires coming out of the top and two wires coming out of the bottom

    one of the wires is heavier like 16 awg
    one wire is lighter like 18awg

    i figured the heavy wire was the series field

    the lighter wire was the shunt field

    so four series field wires and 4 shunt

    I tied the two windings together in series
    so the series wire from the top left winding spliced to the series wire from the top right winding
    same for the shunt wires

    i also measured the resistance of each winding pair and they matched. iirc 530ohms was one set dont remember which

    now there where 4 wires remaining
    one heavy, one light coming out the bottom of each winding

    i brought one heavy to the brush
    i spliced the other heavy to the light wire of the shunt field that became E1

    the other light wire went to the resistor

    the other side of the resistor became E2
    and was connected to the other brush

    i tried to follow the schematic but wasn't sure about polarity
    i just put it together and ran it to see if it would produce DC voltage

    it produced voltage while running it on the workbench but it was only about 103v
    i figured i wasn't spinning it fast enough so i installed it in the machine

    tomorrow i will take it apart and switch the polarity
    so the two windings oppose one another
    the way i wired it i dont think the windings are opposing one another

    i tried increasing the resistance all the way and the output just went lower
    it went down to 24v


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