Mike RzMachine
Cast Iron
- Joined
- Feb 4, 2007
- Location
- Utah
I searched and read up on this, and did some checks with the fluke, but i'm still unclear as to how to wire this motor. from what i've read, it looks like it's what someone referred to as a center tapped motor, not 2 isolated windings.
it looks like from what i've read that i'll need to supply 3 of the phase leads (for discussion called A,B,C) and leave the other three (D,E,F) open to run in one speed. then short ABC together and supply power to DEF.
the motor is a taiwanese 2 spd ( 1750/875 rpm) 3 ph ~1-2hp 220v on a Select mill from what seems to be the 70's. the motor has 6 leads numbered 1 thru 6.
i measured resistance between leads with a fluke 87:
- 4.8 ohms between 1-2, 1-3, 2-3
- 4.6 ohms between 4-5, 4-6, 5-6
- 3.3 ohms between 4-2, 4-3
- 5.5 ohms between 4-1
this 3.3/5.5 ohm pattern repeats itself throughout
can anyone refer me to a wiring diagram of the guts of this motor? i'm having a hard time figuring out whats going on in there just from resistances. the existing wiring on the machine is not really any help, as the previous owner bypassed the contactors and just put a drum switch on the horizontal motor, and removed some switches and most of the wiring that used to run the vertical motor.
i did find this, but i need to confirm that this is the type of motor i have, and also how to identify which leads are the 3 which need to be shorted.
http://www.wiringmanual.com/motor059.html
that's the first task to get me up and running. i was also thinking about adding a vfd to allow me to slow the spindle down as it doesn't have a back gear. the minimum speed is 250rpm in the lowest belt ratio with the motor in low speed. will a low cost V/Hz vfd allow me to slow it down to ~50-100 rpm at the spindle (~175 rpm at motor) or will i need a vector control Vfd to control at such a low speed?
thanks,
Mike
it looks like from what i've read that i'll need to supply 3 of the phase leads (for discussion called A,B,C) and leave the other three (D,E,F) open to run in one speed. then short ABC together and supply power to DEF.
the motor is a taiwanese 2 spd ( 1750/875 rpm) 3 ph ~1-2hp 220v on a Select mill from what seems to be the 70's. the motor has 6 leads numbered 1 thru 6.
i measured resistance between leads with a fluke 87:
- 4.8 ohms between 1-2, 1-3, 2-3
- 4.6 ohms between 4-5, 4-6, 5-6
- 3.3 ohms between 4-2, 4-3
- 5.5 ohms between 4-1
this 3.3/5.5 ohm pattern repeats itself throughout
can anyone refer me to a wiring diagram of the guts of this motor? i'm having a hard time figuring out whats going on in there just from resistances. the existing wiring on the machine is not really any help, as the previous owner bypassed the contactors and just put a drum switch on the horizontal motor, and removed some switches and most of the wiring that used to run the vertical motor.
i did find this, but i need to confirm that this is the type of motor i have, and also how to identify which leads are the 3 which need to be shorted.
http://www.wiringmanual.com/motor059.html
that's the first task to get me up and running. i was also thinking about adding a vfd to allow me to slow the spindle down as it doesn't have a back gear. the minimum speed is 250rpm in the lowest belt ratio with the motor in low speed. will a low cost V/Hz vfd allow me to slow it down to ~50-100 rpm at the spindle (~175 rpm at motor) or will i need a vector control Vfd to control at such a low speed?
thanks,
Mike
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