Henry A. Steelman converter revisited

Hello-
Looking for Peter H to comment.

I was examining this again.
I am looking at the 230V section of the hand drawn diagram.

There are the 4 coils, 2 sets in series, and those series sets in parallel.
To me it seems the sequence is set up so the coils to buck one another.
I mean the coil windings change from CW to CCW, effectively bucking each other.

Another way of saying this, is the coils are connected >N--S> <S--N<, two of these sets in parallel.
I see the 460V diagram has this same feature, connected >N--S> >N--S> < S--N< <S--N<, all in a series.

I assume this "wired-in" buck is serving the same purpose as the shaded pole(s) in the stator winding of single phase, induction run motor. But since the run capacitor acts on the remaining (3rd) set of windings, as well as a start capacitor, I would call this a single phase, capacitor start, capacitor run motor. The difference being that instead of a shaded pole(s) in the stator creating the buck (phase offset), this is accomplished by the magnetically opposed wiring of the windings. The phase offset from the capacitor(s) on the remaining set of windings causes rotation as this arrangement normally would.
Do I have this figured out right?
Thanks for taking the time to understand my explanations of my interpretations.
--Doozer

Please fix the somewhat meaningless title of this thread to more clearly show the subject or it will be closed.

Edit: Thank you.

The H.A.S.-type converter is patented and is more than adequately documented in Steelman Electric Service's own documentation.

The entire point is a three-phase motor may be turned into a single-phase capacitor start/capacitor run-type motor.

H.A.S. serves, predominantly, the petroleum recovery and agricultural irrigation markets with its products.

That its ideas, and patents, also can serve the machine tool markets is most interesting.

That was my point.

http://www.google.com/patents?id=Wr...ages&cad=2#v=onepage&q=Henry steelman&f=false

Peter H-
I am trying to figure out how it works.
I have posted my observation of the connection of the motor coils in a "bucking" arrangement.
I have posted my theory as to the reason for this bucking arrangement, and related it to how a conventional single phase motor operates. I was asking others to comment on if they agree or disagree with my observations and conclusions.
--Doozer

One thing you might note...

The coils in question are on different phases. That means they are displaced in physical space, as well as electrical space. The displacement makes them differ in phase.

Normally, they would be fed 120 degree different phase current, but here it is the same current through both sets.

By reversing the phase on one set vs the others, they may be closer to correct, so that is what is done. 180 is closer to 120 than zero is.......

Thank you to Peter H for posting the Steelman drawing in the Monarch forum and thank you to J Tiers for entertaining my question.

I have two brand new Leeson 5hp 1200 rpm 12 lead motors, and I think I will try this on one of them.

--Doozer

Is there a table or formula for the amount of capacitance needed for the start and run capacitors???

Piper106

Found answer to my own question.

Found this at the Monarch Lathe forum on this site.

peterh5322 writes;

"I have not detailed the values of the capacitors. Clearly, the run capacitors must be 370 VAC, minimum (740 volts when placed in series for 460 volts), and the start capacitors must be 250 VAC, minimum (500 volts when placed in series for 460 volts).

Initial values for C may be obtained from

I = 2 * π * F * C * V

where I is the FLA in Amperes, π is the constant 3.14, F is the frequency in Hertz (the factor 2π converts this frequency from Hz to radians/second), C is the capacitance in Farads, and V is the voltage in Volts.

Final values for each C may be obtained by tuning.

Recommended initial values for Cr are 11.53 µF per FLA amp for 230 volts and 5.77 µF per FLA amp for 460 volts. Use a clamp meter to ensure the current in the start winding doesn't exceed FLA amperes.

Recommended initial value for Cs is ten times the value of Cr, tuning for starting in two seconds or less."

Again thank peterh5322 for this information.


Piper106