SR motor from Maytag Neptune

Under the assumption that this is the 3 phase variable speed motor that was discussed here a couple times in the past, I suspect the best way to get some use out of it would be to get an appropriately rated VFD and wire it to the motor. You may be able to find wiring diagrams and/or spare parts for the controller that blew, but then, it blew once already, right? Aside from that, I'd bet that there are a bunch of features to the factory controller that would be of limited use outside of a washing machine, like the multispeed agitate cycle.

Have fun!

Cheers Trevor Jones

I've never seen a 120VAC VFD. He might have a hard time finding one.

Since Maytag gave him a new motor, I'd think twice about hooking any electronics up to the old one that costs much more than free.

Hmm ...

Mitsubishi FR-U110W-0,1K-UL

a cute little VFD which is supposed to be used with 1/8 HP 240 V three-phase motors, though I am told that it will work well with up to

It runs from 120 VAC single phase input, but will generate 240 VAC three phase. However, like any VFD which I have encountered, it is possible to tell it to reduce the output voltage if you so desire.

Yes -- but if the old motor can be used to run a small machine tool (e.g. a Taig or a Sherline), it might be worth something like the $35.00 that It cost me on eBay about a year ago or so. (I had hopes that it would generate up to 400 HZ (as some of the larger ones will do), so I could use it for playing with some ancient aircraft instruments which I have (an artificial horizon, and a gyrocompass). These were surplus back in about 1960, so they must be no great shakes, but fun to play with.

Enjoy, DoN.

DoN, Recently I purchased a Danfoss inverter that goes up to 1000 HZ. It's for a 5 hp motor. I would consider trading for one that doesn't go up that high if it was new and comparable. ERS

I was wondering about that part.

Agreed. I do have a small AB vfd. I will have to check to see if the output voltage is adjustable.

I dont' think it is the motor's fault that it blows up. From reading various boards, the location and mounting of the board itself contributes to a lot of the problems.

JW

I've got a couple of others -- a 2 hp and a 3 hp one (respectively for my Clausing lathe and my Bridgeport) which will go above 400 Hz, but I don't want to hang the instruments on something that large (and deprive my machine tools of it.)

And somehow, I doubt that my little 1/8 HP VFD would do for your

Enjoy, DoN.

Headline: A VFD will NOT work here.

The SR motor in the Neptune is made by Emerson. SR motors are *not* the same as 3-phase induction motors, not even close. The SR motor has a sailient pole rotor with no windings. The unique aspect is that the rotor has a different number of poles than the stator, so some poles are always slightly out of line when others are lined up. A stator pole that is slightly misaligned with a nearby rotor pole is energized. Magnetic attraction "pulls" the misaligned rotor pole to align it with the stator, thus producing torque. As soon as it is aligned, torque would stop unless excitation is then switched to a pole then slightly misaligned -- and so on.

The advantages to such motors are: capable of very high speed because there are no windings on the rotor, good torque at low speeds, wide range of speed controllability. Disadvantages can be high torque ripple and acoustic noise. A lot of innovation and good engineering went into the Neptune to make it accceptably quiet.

A "sensorless" SR motor drive technique was devel>Anyone have any ideas on how/if this can be used for something useful >w/o a lot of work?

So will it just not run, or will it blow up my VFD?

Research on the Internet seemed to indicate a 3 phase sinusoidal would work, but it is not the ideal waveform. Something square wave is better for max torque output.

I dont' have any sort of actual application in mind for this thing yet, but if it could be useful I will keep it around. If not, off with it(trying to cut down on my packrat tendencies).

JW

I don't know. I know a little about SR motors but much less than some other RCM folks about VFD's. It's conceivable that some SR motors might run on 3-phase excitation, don't know how well. They don't necessarily have 3-phase geometry in the stator.