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  1. #1
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    Default need help with electric motor

    hello,
    working on my SB lathe got a new motor
    trying to figure out if this motor can be reversed,
    thanks for any help Godbless



    marathon-motor.jpg

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    Since the nameplate does not have a wiring diagram for it, I suspect it can not. But the final answer would come from the manufacturer. A spec sheet on it would answer the question without a doubt. The web is your friend:

    Marathon Motors from RS Electric - Marathon Electric Motors Sales

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    Default

    as i'm aging i'm losing the mental capacity to understand these kinds of schematics and motor diagrams.

    basically you've got a thermal protector with 1 input and 2 outputs.

    both outputs are used when the motor is connected for 120, but only one when connected for 240.


    the start winding connects to one end of the winding, goes through a switch and a capacitor... and is connected to the midpoint of the winding for 240v connections, or it is connected to the end of both paralleled windings for 120v connections.. it is also connected through the thermal reset device.

    i think you only need 5 wires exiting the stator to pull this off for a non reversible motor.



    if you want to reverse the motor, find the start winding and cut the lacing on the coil and find where it joins the other coil, and bring the required 6th wire out of the motor.

    alternatively you can reverse the motor if you leave it connected for 240 but you would lose the thermal safety in (this case, counter clockwise rotation). in the event the motor overheated in counterclockwise, it would slow down and stop and as soon as the clutch engaged the capacitor and start winding would be left with current flowing through them. which one blows up first i would give it a 50/50 coin toss.

    this isn't completely unacceptable to me in terms of risk, for a lathe or similar machine. it would never be left "on"

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    Either way, this won't "Plug reverse" like a 3 phase motor will.
    So be aware of this when tapping.

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    Looks like a jet pump motor, Might not be the best motor to use, my guess is it is 3450 rpm if so find something else...Phil

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    Quote Originally Posted by Phil in Montana View Post
    Looks like a jet pump motor, Might not be the best motor to use, my guess is it is 3450 rpm if so find something else...Phil
    Converting the South Bend for ceramic tooling.....

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    thanks for all the help ,i had the original motor for the lathe, well it went up in smoke,,
    thanks for the link to,i had this jet pump motor on a 6" jointer ill have to see what i can find thanks again,
    Godbless

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    Quote Originally Posted by johansen View Post
    as i'm aging i'm losing the mental capacity to understand these kinds of schematics and motor diagrams.

    basically you've got a thermal protector with 1 input and 2 outputs.

    both outputs are used when the motor is connected for 120, but only one when connected for 240.


    the start winding connects to one end of the winding, goes through a switch and a capacitor... and is connected to the midpoint of the winding for 240v connections, or it is connected to the end of both paralleled windings for 120v connections.. it is also connected through the thermal reset device.

    i think you only need 5 wires exiting the stator to pull this off for a non reversible motor.



    if you want to reverse the motor, find the start winding and cut the lacing on the coil and find where it joins the other coil, and bring the required 6th wire out of the motor.

    alternatively you can reverse the motor if you leave it connected for 240 but you would lose the thermal safety in (this case, counter clockwise rotation). in the event the motor overheated in counterclockwise, it would slow down and stop and as soon as the clutch engaged the capacitor and start winding would be left with current flowing through them. which one blows up first i would give it a 50/50 coin toss.

    this isn't completely unacceptable to me in terms of risk, for a lathe or similar machine. it would never be left "on"
    it is running counter clock wise now, i dont no why, the tag says cw-ope ,running on 110 volt?
    Thanks,Godbless

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    EPAIII i can,t seem so find a spec sheet on it, Thanks Godbless

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    Quote Originally Posted by digger doug View Post
    Converting the South Bend for ceramic tooling.....
    LOL Godbless

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    Quote Originally Posted by Phil in Montana View Post
    Looks like a jet pump motor, Might not be the best motor to use, my guess is it is 3450 rpm if so find something else...Phil
    yes its 3450rpm will the rpm cause a problem??
    Thanks Godbless

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    No low speed on the lathe and a really high speed unless you add new pulleys...Phil

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  19. #13
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    Ok ,got a new motor, which is CW or CCW, i need some help wiring the forward & reverse switch
    this motor only has three terminals, see included pic and my switch layout Thanks for all your help
    Godbless

    100_2128.jpg

    lathe-switch.jpg
    Attached Thumbnails Attached Thumbnails lathe-switch.jpg  
    Last edited by love4god; 05-19-2020 at 10:24 PM. Reason: pics


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