2 Phase Motor

[invisabledog]

Thanks for all the replies. I really was hoping to use the vintage motor to power the press, but I think it will be easier and cheaper to just find a different motor. Hopefully I can find an older one that has a vintage look.

 

[John Hasler]

Thanks for all the replies. I really was hoping to use the vintage motor to power the press, but I think it will be easier and cheaper to just find a different motor. Hopefully I can find an older one that has a vintage look.

I'd like to see some photos of it, especially of the data plate (if any). Runnable two-phase motors are rare.

 

[invisabledog]

I'd like to see some photos of it, especially of the data plate (if any). Runnable two-phase motors are rare.

I'll get some pics of it tomorrow when I get out to my shop.

 

[mksj]

This is an short description of Two Phase power I found interesting, I was not aware of this type of 2 phase. http://en.wikipedia.org/wiki/Two-phase_electric_power

Since they are phased at 90 degrees vs split phase 180 degrees, one would need a Scott Transformer ($$) or something similar. Some discussion of converting single phase to 2 or 3 phase http://www.practicalmachinist.com/v...fd/single-phase-two-phase-three-phase-158678/

Would seem that it is more economical to replace the motor.

 

[John Hasler]

This is an short description of Two Phase power I found interesting, I was not aware of this type of 2 phase. http://en.wikipedia.org/wiki/Two-phase_electric_power

Since they are phased at 90 degrees vs split phase 180 degrees, one would need a Scott Transformer ($$) or something similar. Some discussion of converting single phase to 2 or 3 phase http://www.practicalmachinist.com/v...fd/single-phase-two-phase-three-phase-158678/

Would seem that it is more economical to replace the motor.

A Scott T is just two transformers with appropriate taps. A capacitor phase-shift network would be cheaper, though.

 

[Alan Douglas]

While I've never run one, a two-phase motor ought to work on single phase, at half power. Any ordinary induction motor is a two-phase motor, but the second phase is normally called the start winding. With a capacitor in series with it, there should be enough torque to start the motor in the right direction. Of course there's no centrifugal disconnect switch, and designing for a starting relay could be tricky, so you're best off by considering it a permanent-split-capacitor motor and using a motor-run capacitor. Within limits, the larger the better; probably the simplest way is to try something and see what happens.

 

[master53yoda]

I just picked up an antique Champion camelback drill press. It came with a General Electric motor. The motor is 1.5 hp 220v 2 phase. Is there a way to get this to run on single phase? The guy I got it from claimed to have had it running years ago, but didn't remember how it was wired. There are only 3 wires in the junction box on the motor.

True 2 phase power used 4 conductors, some of the motors used 3 conductors like a 3 phase motor but they can be
ID by the fact that one of the 3 wires will be larger then the other 2 because it carries about 1.5 times the current that the other two wires carry. the reason for the difference is that it carries the vector sum of the 2 90 degree angle motor windings. True 2 phase power was used for a very short time in the early 1900s. I have never seen a true 2 phase motor.

Some of the the early three phase power supplies were connected to 2 of the three phases and the motor generated the third phase internally, but the phase angle between the two connected transformers was 120 degrees. the power delivered to the building was 240 delta with a main phase for 120 volt power available. Two of the legs to ground or neutral was 120 but the third leg was about 180 depending on load balance. This is also referred to as wild or bastard leg three phase. when looking at the transformers on the pole one was considerably larger then the other. Those "2 phase " motors used on this power system were really 3 phase motors .

The idea that the common 120/240 volt systems are 2 phase is a misnomer because the system is simply a single phase 240 Volt transformer with a grounded center tap of the transformer as neutral for 110 Volt.

208 Volt three phase is a Y configuration with a grounded center tap of the wye as neutral. Any leg to neutral or ground as 110.

I hope this helps a little

Art B

 

[invisabledog]

Re: Picture, 2 Phase Motor

This is a picture of the motor. Couldn't get a clear picture of the tag. It reads Induction motor, General Electric, Schnectedy NY. I'll try again tomorrow for a clear picture of the tag.

View attachment 88253

 

[John Hasler]

Re: Picture, 2 Phase Motor

This is a picture of the motor. Couldn't get a clear picture of the tag. It reads Induction motor, General Electric, Schnectedy NY. I'll try again tomorrow for a clear picture of the tag.

I see the word "PHASE" on there but I can't make out the number.

 

[Wreck™Wreck]

True 2 phase power used 4 conductors, some of the motors used 3 conductors like a 3 phase motor but they can be
ID by the fact that one of the 3 wires will be larger then the other 2 because it carries about 1.5 times the current that the other two wires carry. the reason for the difference is that it carries the vector sum of the 2 90 degree angle motor windings. True 2 phase power was used for a very short time in the early 1900s. I have never seen a true 2 phase motor.

Some of the the early three phase power supplies were connected to 2 of the three phases and the motor generated the third phase internally, but the phase angle between the two connected transformers was 120 degrees. the power delivered to the building was 240 delta with a main phase for 120 volt power available. Two of the legs to ground or neutral was 120 but the third leg was about 180 depending on load balance. This is also referred to as wild or bastard leg three phase. when looking at the transformers on the pole one was considerably larger then the other. Those "2 phase " motors used on this power system were really 3 phase motors .

The idea that the common 120/240 volt systems are 2 phase is a misnomer because the system is simply a single phase 240 Volt transformer with a grounded center tap of the transformer as neutral for 110 Volt.

208 Volt three phase is a Y configuration with a grounded center tap of the wye as neutral. Any leg to neutral or ground as 110.

I hope this helps a little

Art B

This is correct in my experience, certain parts of the old manufacturing areas of Philadelphia were predominantly 2 phase and remained that way into the mid 2000"s when I stopped doing that kind of work.
4 wires for motors, I recall having to switch them in pairs to change direction.