2 phase? What is this symbol?

[Kurt Wyberanec]

Looking at a mid 2000s scmi saw and it says 2 under the ~ block on the name plate... is phase? And what does the 2 signify? Is this a 2 phase machine and if so what does that mean? I've seen this as a 3 on many machines too... not my area of expertise.... thanks

[derek labian]

You might post a picture of the plate to get a quick/accurate answer if you have it.

[Michael Schuch]

No motor is going to be labeled 2 phase. It is either 1 phase 120v, 1 phase 240v or 3 phase. So, no, definitely not.

[Phillip Mitchell]

Well....there was/is 2 phase power still in certain, shall we call them “historical” locations - Philadelphia, for example, if I’m not mistaken. From my limited reading on the subject it seems like a problem I would not want to wrestle with and I have many 3 phase machines.

I cannot, however, see any logic behind an SCMI machine having a factory stamped 2 phase motor, but maybe someone else out there has experience.

A few photos would help.

[Rod Sheridan]

Looking at a mid 2000s scmi saw and it says 2 under the ~ block on the name plate... is phase? And what does the 2 signify? Is this a 2 phase machine and if so what does that mean? I've seen this as a 3 on many machines too... not my area of expertise.... thanks

No, it wouldn’t be 2 phase power, 2 phase is a three wire system with a 90 degree phase displacement.

I’ve only seen it in aviation applications…… Regards, Rod.

[Patrick Kane]

Are you sure it isnt a poorly/incomplete stamp of the number "3"? You can do some backwards engineering if you have the KW/HP rating, full load amps, and voltage of the motor.

[Jared Sankovich]

Well....there was/is 2 phase power still in certain, shall we call them “historical” locations - Philadelphia, for example, if I’m not mistaken. From my limited reading on the subject it seems like a problem I would not want to wrestle with and I have many 3 phase machines.

I cannot, however, see any logic behind an SCMI machine having a factory stamped 2 phase motor, but maybe someone else out there has experience.

A few photos would help.

Philadelphia seems to be the most common place to find OWWM with 2 phase motors.

[Erik Loza]

Some of the early Italian machines showed 2-phase on the motor plates. Every one of those I ever saw was a 1-phase machine.

Erik

[Frank Pratt]

2 phase is something we learned about in electrician school, but it's little more than a curiosity and was never used in mainstream power distribution.

[Bill Dufour]

Some old school electricians and EEs referred to 240 volt as two phase. That is not the same as true two phase since it only requires two hot wires not three or four.
Bill D

[Frank Pratt]

Some old school electricians and EEs referred to 240 volt as two phase. That is not the same as true two phase since it only requires two hot wires not three or four.
Bill D

I personally don't know any who do that, but if they did, they'd be dead wrong.

[Greg Funk]

I personally don't know any who do that, but if they did, they'd be dead wrong.

Technically, in North America, a neutral and two hots is two phases 180 degrees apart. In some parts of the world they will supply a residence with 2 out of the three phases from a conventional 3-phase distribution system. In that case you have a neutral and two hots 120 degrees apart. Doesn't make much sense in the context of a motor though.

[Rollie Meyers]

2 phase is something we learned about in electrician school, but it's little more than a curiosity and was never used in mainstream power distribution.

In the early days of electricity, 2Ø was the original polyphase power, it's largely disappeared but there are a few hangers on still in existence in Philadelphia, PA, & Hartford, CT.

[Erik Loza]

Photo I took of a CU300 Smart ID plate, circa 2006. Look closely at the motor phasing designation. This is a 1-phase/230V machine.

Erik

A1DF5DFB-38E3-4675-A640-E65E5A006556.jpg

[Frank Pratt]

I suspect regional terminology variations.