2 Phase Motor

[invisabledog]

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.

 

[John Hasler]

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.

It's either three phase or single phase. Post photos of the dataplate, the inside of the junction box, and any diagrams found inside the junction box or anywhere on the motor.

 

[Jamiethesquid]

The 15" Regal Leblond I bought was also listed as "2 Phase". I believe that this is a common misnomer for 220v AC as it takes 2 breakers. But I will defer to the electrical gurus among us. I hope that it is not something more nefarious than that, because I haven't got the lathe home yet.

 

[invisabledog]

It's definately 2 phase. It's a turn of last century motor circa 1916. 2 phase was common at that time. Can't post a pic right now, will try to get one up in the next few days.

 

[rwm]

Well 220 is kind of 2 phase because it uses opposite phases at +110v and -110v. Is there an older 2 phase that I am unfamiliar with?
If you run it on 110v (which is single phase between the neutral and one phase) it will run at reduced power by at least a factor of 4 and may not run well at all.
It is really easy to run a 220v line if you are near the breaker box. In a pinch, you can find 2, 110v receptacles that are on opposite phases and use the hot leads from both receptacles to run it. I don't recommend that but it works.
R

EDIT:
Disregard the above sorry. I should have checked first. There is an old 2 phase power that uses offset phases. I just read about it. It's not 180 deg offset like current 220v.
Is it possible you could use two of the phases of a 3 phase VFD? I don't know if that would damage the VFD. Maybe you could put a dummy load on one phase?
2 phase power is still in use in Philly PA if you want to move!
R

 

[John Hasler]

It's definately 2 phase. It's a turn of last century motor circa 1916. 2 phase was common at that time. Can't post a pic right now, will try to get one up in the next few days.

As far as I know GE made no 2 phase motors. Westinghouse did but I would be surprised to see one being installed as late as 1916.

 

[John Hasler]

Well 220 is kind of 2 phase because it uses opposite phases at +110v and -110v. Is there an older 2 phase that I am unfamiliar with?
If you run it on 110v (which is single phase between the neutral and one phase) it will run at reduced power by at least a factor of 4 and may not run well at all.
It is really easy to run a 220v line if you are near the breaker box. In a pinch, you can find 2, 110v receptacles that are on opposite phases and use the hot leads from both receptacles to run it. I don't recommend that but it works.
R

220 is not two phase. It's single phase with a center tap. Two phase involves a four wire system with the voltages at 90 degrees. It's what Tesla first came up with, which is why Westinghouse sold two phase systems for a while.

 

[invisabledog]

From the little I understand about it, it can't be run off a vfd. The three phase is 120 degrees apart and the 2 phase in this motor is 90 degrees. Somehow the previous owner was running it in his shop, but I don't know how and he can't remember. He had someone else hook it up for him. It also runs at a lower rpm than the normal 1725. I can't remember what it said . I'll have to check when I get back to the shop.

 

[CluelessNewB]

Yes two phase was/is a thing. Assuming you could find one and had 3 phase power available a "Scott T Transformer" would convert 3 phase to 2 phase. My guess is it would be easier to find another motor. That the motor only has 3 wires is very odd for a 2 phase motor.


http://en.wikipedia.org/wiki/Scott-T_transformer


You may find this interesting:

http://www.phillyfacility.com/two_phase.htm

 

[John Hasler]

From the little I understand about it, it can't be run off a vfd. The three phase is 120 degrees apart and the 2 phase in this motor is 90 degrees. Somehow the previous owner was running it in his shop, but I don't know how and he can't remember. He had someone else hook it up for him. It also runs at a lower rpm than the normal 1725. I can't remember what it said . I'll have to check when I get back to the shop.

You could use a capacitor phase shift network similar to that used for a so-called "static phase converter" to run a two-phase motor on single phase. There also is a way to connect a four wire two-phase motor to a four-wire three-phase source. The lower rpm just means that it has more than four poles. Not uncommon, especially for older motors.