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Full tear down and Rebuild of a 10EE Round Dial

I got the F/R switch wired up.
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It's got a couple of contacts that are quite worn. I'll need to either find a donor switch for replacments or make my own contacts. It should be good enough to at least test the M/G as first step will be to make sure the motor portion of the M/G works before moving on to testing the Exciter and the DC motor.
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Since I dont have the headstock on the lathe yet, I'm using a couple of spring clamps to hold the switch here. Sketchy, but its staying in off portion for the first set of tests.
I picked up a 3 Phase 30 amp fused disconnect for the lathe off of Amazon's ware house deals for $50, instead of mounting it directly to the back of the lathe, I will eventually mount it to the wall behind the lathe for easy access. There will be a plug between it and the lathe, so I can more the lathe for cleaning, etc If I ever need to.

I didnt have a thread chaser in the correct size, so I used a tap to clean the threads for the Start / Stop Knee switches.
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The pilot light was dead, so I replaced it with an LEDimage.jpeg
The new heater's for the motor's protection switch arrived.
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I am going to go with these ones based upon my calculations.
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They are identical to the factory standard ones, other than these have an extra winding on them.
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One then gets installed on each side.
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Ok, now I am getting close to powering up. One thin that had been bugging me was, why is the Start capacitor at 300Uf so much smaller than the 60Uf run cap? Well I decided to pull it out of the mounting bracket I had made. Its rated for 45VDC, no AC! Glad I checked! I ordered up a new Starting capacitor off of Amazon, its 300UF, and rated for 450VAC.
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Thats more like it. Since this cap is larger, it won't fit in the M/G connection box, so I need to mount a second box on the lathe. I decided, its probably smart to move both caps into this second box, to clean up the main connection box.
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Once I figured out the mounting locations, I used a transfer punch to line everything up, and then installed rivet nuts to install everything.
 
Here is the finished layout of for the Capacitor box.
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I'll need to bring wires over for T1, T2 (these are the Line voltage into the M/G's main panel) as well as Motor Lead #3. These 3 leads will then power the motor.
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The idea, is once the motor starts running the SUPCO Relay cuts out the Start capacitor. This way I can power the 3Phase motor on single Phase.

I then checked each capacitor with my Fluke meter.
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60.7 uF for the run capacitor. Perfect.
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308uF for the start Cap, just as it states on it. Perfect.
I then sprayed the lid of the cap box with clear insulating varnish, same as what I used on the motor windings. I also brushed it on the contacts of the Supco relay, as added insurance to prevent any chance of a short to the top of the cap box.
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I had a bunch of a Watertight conduit left over from another project, so I am using that to get the lines to the Cap box. Instead of using the cheap plastic water tight fittings, I am using the metal version of them.
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Not only are they metal, but they also use a metal furl that screws into the watertight conduit. These are pretty damn secure.
I drilled and taped mounting holes for the box behind the DC panel and bellow the Knee switch. These allows you two just remove two panels on the lathe to access all of the AC motor connections.
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For the main M/G Panel, I needed a way to add another hole for the conduit. I ended up using my Festool drill with its right angle attachment.
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That worked perfectly!
Here is the M/G panel fully wired up.
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I tried to keep it as tidy as possible, but there is a lot of wiring in there. Really glad I chose not to cram the caps in as well! I then removed the DC motors connections from the panel and taped over them. As I want to test the M/G alone first, then the Exciter before moving on to the DC motor, so I can logically problem solve any issues that I might have.

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For the main line connections on the back of the lathe, I used a contact bar instead of wire nuts. Since we are going to be running on 240V single, phase L3, does not have a connection. I am brining a Neutral to the lathe as well, in case I decide to add a work light latter. The grounds are screwed to the back of the box.

Ok time to power it up!
I flipped the breaker on, then hit the start button on the Knee switch. SUCCESS!!!! IT powered right up instantly! I was pretty excited and thought I was taking a video, but evidently I had my phone in photo mode still.

I immediately switch the lathe off, and verified the motor was running in the correct direction. Sucess.

Awesome, the single Phase conversion powers the M/G right up!
 
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I then proceed to check the parameters using my Fluke Meters. I want to make sure everything is correct before moving on to testing the Exciter.
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First I checked the Voltages in the wires to the motor from the Cap box. My procedure is set the meter up, turn lathe on for a min or so, get a stable reading, turn off lathe, and reset leads, and repeat.

Voltage across T1 and T2 is 238.5. Same as it is from the line to the machine.
Voltage across T1 and #3 is 296.8 this seems a bit high
Voltage across T2 and #3 is 399.9V Ok, this seems quite high with the motor running full speed.

I'm starting to think the Start Cap isn't dropping out. I'm not totally sure yet. The lathe is firing up instantly each time.

I then proceeded to check the amperage on each line from the Cap box to the M/G panel using a Fluke clamp meter.
#3 read 9.5 Amps. Thats bellow the max if 17.11A I had calculated...
I then checked T2 it read 9.6 Amps, ok this is pretty close to #3's reading. It's about half of the value I had calculated for T1 and T2's max amperages of 22.8A. That makes sense I think as there is no load on the M/G
I then proceeded to check T1 and got a reading of 0.1 Amps.
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Humm... something clearly doesn't seem right. Did I get the meter properly clamped around the line? I turned the lathe off, reset the meter on T2 turned it back on and got a reading of 9.6A same as before. Ok, meter is working. Turned of the lathe off, repositioned the meter on T1 and turned the lathe back on again. Still reading 0.1 for T1

BAMB! Holly shit what was that, I know have a shit ton of smoke coming from the Cap box. Fu(K! I immediately turn the lathe off, and then run over to the breaker and turn it off! That was quite the experience, especially with my head down there reading the amp meter. I got everything aired out. I then grabbed my meter and made sure there was no voltage left at the Cap box lines. Looks like one of the caps exploded.
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I then pulled the cap box out, to get a better look.
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Sure enough the Start cap blew. What a mess! I am really glad this wasn't in the main M/G panel! Now to figure out what happened.

Here is the schematic of how I have it all wired.
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Here is the Supco Relay Schematic
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Based upon this, can anyone confirm I had the start cap wired to the correct terminal for the relay to remove it from the circuit?

I had the Supco Pickup Voltage set to 250V.

PICK-UP VOLTAGE
370 130 310 250 180
Patent No. 5528120
INSTALLATION
1. Turn power off.
2. Set the desired Pick-Up Voltage on the APR dial.
If you don’t know what the Pick-Up Voltage is, proceed as follows: * For equipment rated for 115-120 volts set the APR5 dial to 190.
* For equipment rated for 208-240 volts set the APR5 dial to 350.
(The above setting will satisfy most motor applications. However, the voltage ranges represent averages that may not be adequate for some applications. It is better to set the Pick-Up Voltage ac- cording to the equipment specifications.)

If someone can confirm I have the start cap wired to the correct terminals according to the Supco Schematic, I think my next course of action is to order a new start cap and then do the following:

If you wish to verify the APR5 setting:
1. Place an analog clamp-on ammeter over either one of the two wires from the start capacitor, or the wire from the start winding.
2. Apply power and observe the ammeter.
3. CORRECT SETTINGS: The Pick-Up Voltage is properly set if the relay contacts open when the unit is up to 70%-80% of full speed. Under normal conditions the motor will reach its full speed within 0.1-0.2 seconds. The ammeter cannot react that fast, however you will observe some swing of the needle.
4. If the Pick-Up Voltage is set too high, the voltage on the start winding will not reach the level of the APR5 setting. The needle of the ammeter will swing to its maximum arc and hesitates for 1-1.5 seconds before returning to zero. It simply means that the APR5 automatically opened the contacts after the safety time limit. Turn the setting to the next lower mark. Each mark is about 30 volts. Repeat until the motor and APR5 operate as in paragraph 3.
5. If the Pick-Up Voltage is set too low the relay contacts will open before the motor has a chance to get to the full speed. The motor may not start at all. The needle of the ammeter may swing and return to zero too fast. The relay opens the contacts before the motor has a chance to reach the desired speed. Increase the voltage setting by one mark until the relay and motor operates as indicated in paragraph 3.
 

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Looking back I think the .1 amp on T 1 makes sense as that is just opening / closing the circuit. The 400v between T2 and T3 has me concerned. Either the relay isn’t opening the contacts and is defective, or I need a higher Voltage rated relay ( but it’s documented people using this one) or I need to lower the pick up voltage, or the Chinese capacitor on Amazon was junk. I also wounded is the multiple starts in a short period of time also over heated the start cap. I need to start eliminating variables.

Can someone explain to me the difference between these three capacitors and what one is better for this application?

450VAC 300Uf run cap for $18.99 Chinese crap? this is one that blew.

440VAC 300 UF for $102.67

440VAC 300UF for $91.40

Thanks!
 
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...
#3 read 9.5 Amps. Thats bellow the max if 17.11A I had calculated...
I then checked T2 it read 9.6 Amps, ok this is pretty close to #3's reading. It's about half of the value I had calculated for T1 and T2's max amperages of 22.8A. That makes sense I think as there is no load on the M/G
I then proceeded to check T1 and got a reading of 0.1 Amps.
...
22.8A max makes no sense to me. Nameplate full load current at 220 VAC is 13.7A.

Cal
 
22.8A max makes no sense to me. Nameplate full load current at 220 VAC is 13.7A.

Cal
The 22.8A value is what is calculated according to the Steelman literature with the 3Phase to Single phase conversion:

The ampere reading on the input side (L1 & L2) of the H-A-S Static Converter will read as expected with any single phase equipment. That is, as the load increases, amperage will increase and both lines will be carrying the same amount of amperage. It is important to remember that these two lines will be carrying more amperage than the nameplate of a three phase motor will indicate. This is true because it will be carrying the same total power on two lines that it would be carrying on three lines when operating on three phase. The current required from single phase lines times 1.73 delivers the same power as three phase provided that the system efficiency and power factors are the same. For an H-A-S Static Converter-motor combination, the exact full load amperage taken from the single phase lines is calculated as follows:

(ConvertedMotorFLA=1.73PFH−A−S∗PF3Phase∗Eff3PhaseEffH−A−S∗FLA3Phase)

Where:

  • PFH−A−S= Power Factor of H-A-S Static Converterx and motor combination
  • PF3Phase= Power Factor of H-A-S Static Converter and motor combination
  • Eff3Phase= Efficiency of three phase motor from nameplate or motor data
  • EffH−A−S= Efficiency of H-A-S Static Converter and motor combination
  • FLA3Phase= Three phase full load amps from motor nameplate
At full load conditions, it has been found that the power factor of the H-A-S Static Converter – motor combination is approximately .95 and its efficiency to be very nearly the same as when the motor is operated on three phase. The ratio of Eff3Phase/EffH-A-S then becomes unity and our equation simplifies as follows:

(ConvertedMotorFLA=1.73 /.95∗PF3Phase∗FLA3Phase=1.82∗PF3Phase∗FLA3Phase)

FLA3Phase for this motor is 13.2A

ConvertedMotorFLA=(1.73 /.95) x PF3Phase x 13.2

ConvertedMotorFLA= 1.82 x .95 x 13.2

ConvertedMotorFLA = 22.8 Amps!

The above relationship should be used to determine maximum L1 and L2 heater coil and fuse sizing.

At first thought, it would appear that this amperage is excessive; but it must be remembered that due to the winding connections, the I2R losses are spread out over all the motor windings.

Evidently, The T3 amperage may read higher than T1 amperage at no load or partial loads. This condition is normal and will not damage the motor or the converter. The T3 amperage will decrease as the load on the motor increases, while T1 and T2 amperages will increase as the motor approaches full load conditions. Although the actual amperages for L1 and L2 may be easily calculated as shown above, the amperage to use for the proper heater coil sizing for T3 is not so easily obtained. For practical purposes, however, the maximum T3 amperages should be calculated as follows:


T3 = .75 x FLA

So T3 = .75 x 22.8
t3 = 17.11A



The overall input wattage (I2R) of the motor at full load when operated with an H-A-S Static Converter does not exceed the overall input wattage of the motor when operated on three phase. For this reason, at full load conditions, the motor will have the same approximate temperature rise as if operated on three phase power.
 
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Why is your current so high in a system that has no load?
Thats a good question. With no load, its drawing half of the amps I calculate a full load would be for the conversion to 2phase.

Ok, time to do a post mortem and see if we can figure out WTF happened.

I removed the Capacitors and relays from the lathe, so they are out of the equation

First lets check the resistivity in the 3 sets of motor windings.
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T1 to T2 is 0.8Ω this is essentially across 4 of the windings.
T1 to #3 is 1.5Ω this is essentially across 2 of the windings
T2 to #3 is 2.2 Ω this is essentially across all the windings
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Here is the readings I got with my meter (red was while it was running before the cap failed. Blue was after the cap failed and with both the caps and the relay removed. The circles are where I took the readings with my clamp meter.

I dont think this is where the problem lies. If needed I can check each set of windings individually, or even break out my megger, but I'm feeling confident the motor is good.

Ok, now lets look at what actually failed. I think the problem lies with one of these two components are a combination of.
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First lets look at the start cap. It blew the end right off of it. It appears to be made up of smaller caps. Lets have a look inside.
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My Knipex electrician scissors made quick work of the plastic housing.

Thats a pretty sizable package for 4 small caps.
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Ok, what are the using for the caps in this?
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all 4 are 330uF 200WV caps.
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Ok, to me this looks like two sets of 330uF 200WV caps in series, then wired in parallel. Not sure how they are getting the 450V rating.
Can someone explain that to me, or verify my thinking that this should only have been rated at 200v? When I tested it prior to install with my fluke meter I got a reading of 308uF.

Ok, moving on to the Supco AR5 relay. Hey look, USA on the circuit board... you dont see that very often these days.
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The contacts feel stuck closed. With a bit of force from my finger I got them to open with a pop. Lets have a closer look at the contacts.
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That looks to me, like they did in fact weld themselves shut.

Ok, so what would cause the relay to weld its self shut? Too many amps? Too much voltage? Did I have the pickup voltage set too high on it? The relay was rated for
110 - 270 VAC, Single Phase 30 Amps

I am thinking a better quality cap is in order. Second, I need to see what the actual specs are for Supco Relay and varify with the meter what it is actually seeing. If anyone has any in site I all years as I am pushing my limited knowledge of this stuff.

Also, while I had the meter out, I checked the following (none of these where in circuit when I was testing the Motor portion of the M/G:

GA1 to GA2 was 2Ω
GS1 to GS2 was 0.2Ω
GF1 to GF2 was 103Ω
E1 to E2 was 3.4Ω
Exciter E1 to Gen E2 was 527.3Ω

Do these values look correct? I have not made any changes to the factory wiring schematics of the Generator side, Exciter side or the DC motor. Thanks.
 
I would go to your local HVAC supply store and buy what they sell.
A place like that will get immediate feedback if they are selling
bad stuff.

A couple of comments;

Years ago I built a 2 HP rotary phase converter. I had a 12" by 12" box filled
with AC capacitors. About half were the run capacitors and the other half
were the start capacitors. You are trying to build a 3 HP phase converter
and you are using far fewer capacitors than I had. I used information
that I got off the net for my project. I used a 1/2-second timer relay for
the start circuit cutout. It is too complicated to figure the proper cutout
current for these home-made phase converter systems.

Are you sure that you have the motor windings connected properly?
Your drawings seem overcomplicated. Simply stated, when the motor is
wired for 220V each phase winding pair is wired in parallel. When wired
for 440V they are in series. If you get one winding reversed, you
will create a dead short. If you don't trust the labeling, it is not too hard
to figure it out yourself.
 
I studied your drawing some more, and you have some mistakes. The drawing
to the right is correct, although the two star points can be connected together
but it will work the way shown.

Wires B4, B5, B6 and B10, B11, B12 are the center of the star and can all be
connected together, but are connected to nothing else. Wires B1 and B7 are
connected together and form one phase. Wires B2 and B8 are connected
together and form the second phase. Wires B3 and B9 are connected together
and form the third phase.

The idea of a phase converter is to apply your 220 volts to two of the three motor
leads. Let's call the motor leads M1, M2, and M3. Let's call the incoming 220V
power P1 and P2. Connect P1 to M1, and connect P2 to M2.

That leaves M3, which needs to be connected to the run capacitors. The other
ends of the run capacitors are connected to either P1 or P2, depending on the
direction that you want the motor to run. To start the motor, you need to connect
another capacitor in parallel with the run capacitor for a moment to start the
motor turning. After that, the start capacitor drops out.

It gets a little more complicated when you "tune" the circuit to get a balanced voltage
on the M3 connection. That is why I had a box of capacitors.
 
...

Also, while I had the meter out, I checked the following (none of these where in circuit when I was testing the Motor portion of the M/G:

GA1 to GA2 was 2Ω
GS1 to GS2 was 0.2Ω
GF1 to GF2 was 103Ω
E1 to E2 was 3.4Ω
Exciter E1 to Gen E2 was 527.3Ω

Do these values look correct? I have not made any changes to the factory wiring schematics of the Generator side, Exciter side or the DC motor. Thanks.
That all looks fine. Any time that you're taking a reading that involves a commutator (for example GA1 to GA2) the reading can be a bit high if the machine hasn't run in a while. There's probably some oxidation that forms on the commutator as it sits. If you check GA1 to GA2 again after the generator has been in operation, you'll usually find it's closer to 0.1Ω.

Cal
 
I ordered a new Run capacitor from Newark as they are the only one that had one with the exact specs I was looking for in a continuous duty. Its 300uF and 440V. Only issue is that Newark's shipping division is completely incompetent and they shipped it in just a padded envelope instead of boxing it.
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Notice the terminals are bent! After dealing with their horrible customer service for over a week, they finally agreed to refund my card and I ordered a replacement. That one showed up a week latter, with the same packaging issues and the same bent terminals. I contacted them again, and still waiting on a response another week latter... I wont be doing business with them. They could at least use customer service reps based on this continent.

I'm hoping they will send a replacement in a box, third time is the charm, but we will see. I did test the last one after I bent the terminals back and it does test good.
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While waiting for Newark to resolve the issue, I decided to clean up the motor's name plate.
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I used a black Lacquer stick to fill in the engravings,
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The excess gets ripped off, then I hit it with a couple coats of clear coat. This then gets installed with drive screws.
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Turns out the motor uses a #5 drive screw, which is the only size I dont have on hand and is the only size McMaster doesn't stock... odd. I then drilled the motors mount holes with a #29 drill and installed the name plate using a #6 drive screw.
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The name plate came out ok, the engraving wasn't that deep, so really hard to get the lacquer to stick in it.

Moving along, I didnt like how I had setup the terminal box previously on the M/G, so I decided redo it with a dedicated terminal strip for the motor leads... this will allow me to test various configurations, more on that latter.
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Previous box, with the new one on the right.
First step is to use my transfer punches to locate the screw mounting holes for the box.
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Those made a quick job of accurately locating the screw holes. For small holes in sheep metal, I find a step drill works best. I use a sharpie to mark it so I dont drill too large of a hole.
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For larger holes I like to use my knockout punches.
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I have a Klien set that serves me well for this.
 
The knockouts use a set of dies for each size that require you to first drill a smaller pilot hole.
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You insert them into the pilot hole and tighten with a wrench.
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This results in a much cleaner hole, that unlike a hole saw hole, does not need to be deburred.
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The chips are also a hell of a lot easier to clean up too.
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Thats a big plus if you are adding conduit to a box already in service as it keeps the box clean from metal chips.
Here is the new box installed and wired up with the motor leads.
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Thats way cleaner and more organized than my previous attempt. I'm glad I re-did it!
Next I tested each pair of windings with my Fluke meter
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I got the following results for each pair of motor windings:
1~4 = 0.9Ω
2~5 = 0.8Ω
3~6 = 0.9Ω
7~10 = 0.8Ω
8~11 = 0.9Ω
9~12 = 0.8Ω
Ok, resistance across each individual coil looks great!

Next, I tested motors insulation by testing each lead to ground with my Klein Megger
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I started off testing at 250V and got >4000MΩ for each lead to ground, I then redid the test at both 500V and again at 1KV and got the same >4000MΩ reading for each. Finally I tested between each motor Terminal and still got >4000MΩ with the exception of the coil pairs. So the motor is sound electrically. Not bad for a garage motor rebuild.
 
Cal Haines was kind enough to draw up the various wire diagrams for connection the M/G motor to AC power. I hope he doesn't mind me sharing these here.
Here is the standard 3 Phase High-Voltage wire Diagram
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Here is the standard 3Phase Low Voltage diagram
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Notice, the High Voltage Diagram have the motor's coils in SERIES with 4 coils between any of the Terminals. The Low Voltage diagram has them in PARALLEL .

Now looking at the Steelman connection diagram for converting the motor from 3Phase to single:
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The T1 and T2 circuits are also in PARALLEL, however the T3 circuit is in SERIES. This is interesting. It brings up the question, can you use a start / run capacitor setup with the standard Low-Voltage connection to get a 2 Phase motor?
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Both the Steelman and the Low-Voltage diagrams share the following jumpers
1~7
2~8
4~5
10~11

Noticing this, I then wired those jumpers and placed them behind the Generator wires as these connections will be used regardless, and they are all part of the original factory configuration.
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I now have a good test bed to do some testing and see if it is possible to use the Low-voltage connection with a run capacitor to run on single phase, and see how it compares to the Steelman method of converting to single phase.

Testing any two coils in Series gives me 1.6Ω. This is good, as they all tested the same. This makes sense as testing each of the individual coils gave me readings between 0.8 and 0.9Ω so 0.8Ω plus 0.8Ω = 1.6Ω. Along those same lines, if we then wire two of the series of coils in parallel we would take the 1.6Ω divide it by 2 and we end back up with 0.8Ω same as what each individual coil tested at. The Electrical Theories that I "learned" back in the few EE classes I took in college are quite foggy, but this is at least making a bit of sense to me.

Ok, lets wire it up for the standard 3Phase Low Voltage connection and see what we get.
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For this configuration we add the following jumpers
3~9
5~6
11~12
The motor is now in the 3 Phase low-voltage connection identical to the name plate.
Lets see what we get for the following connections
T1 ~ T2 = 0.9Ω
T1~T3 = 0.9Ω
T2~T3 = 0.9Ω
Ok this is what we would expect based upon the calculations above.

Now, lets remove the 3 sets of jumpers for the Low-Voltage connection and then wire it for the Steelman conversion:
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For this we add only two sets of jumpers
1~12
9~6

Now lets test our Terminal combinations again
T1 ~ T2 = 0.9Ω. Same as the standard low voltage connection above, since it is the same connections.
T1 ~ T3 = 1.6Ω Same as any two coils in series
T2 ~ T3 = 2.3Ω Interesting. Ok, looking back at when I tested the motor previously with the Steelman conversion, before the start cap blew, I was getting a voltage reading across T2 ~T3 of 400V. Interesting.. .thats high voltage territory. Humm.

Lets move the jumpers around and see what we get with the motor in the High-Voltage setting. In this setting, each combination of T1~T2, T1~T3 and T2~T3 is identical, in theory I can just test one of these and see what we get for resistance.
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Turns out it is 2.3Ω! That is exactly the same as I got with the T2~T3 connection in the Steelman configuration.

So this is making a bit more sense, as to why I got different voltages in my previous testing.

So in summary with the Steelman configuration

238.5V T1 ~ T2 = 0.9Ω. Same as the standard low voltage connection above, since it is the same connections.
296.8V T1 ~ T3 = 1.6Ω (two coils in series)
399.9V T2 ~ T3 = 2.3Ω

Since T2 ~T3 also has the start / run caps connected across them, I believe the higher voltages here make sense...(If I am thinking correctly, the capacitor is what provides the phase shift so the motor can start, and because of the phase shift, the meter is reading it as high voltage.

Next step is to add the start / run capacitor to the system and see where we are at. I really wish I had an oscilloscope for the next round of testing, just to better understand what exactly is going on.
 
Haven't been WITHOUT anywhere from one to four 'scopes since 1954. And refuse to be without.
I’ve been trying to find a suitable and reasonably priced scope. Seems there are a ton out there in the $100-200 problem is finding one capable of the voltage range found in the 10Ee and then the probes are stupid expensive. Hell even the fluke probe set for my amp meters was $200.

Open to suggestions on a scope and lead combo.
 
Ok, thinking about this some more,

After measuring resistance in each configuration, I dont think the Low-voltage with the caps across T2T3 is going to work.
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In the standard, Low-Voltage configuration we get:
The motor is now in the 3 Phase low-voltage connection identical to the name plate.
Lets see what we get for the following connections
T1 ~ T2 = 0.9Ω
T1~T3 = 0.9Ω
T2~T3 = 0.9Ω
Thats with each terminal set seeing 220/240V across it.

With the Steelman configuration
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T1 ~ T2 = 0.9Ω. Same as the standard low voltage connection above, since it is the same connections.
T1 ~ T3 = 1.6Ω Same as any two coils in series
T2 ~ T3 = 2.3Ω Interesting. Ok, looking back at when I tested the motor previously with the Steelman conversion, before the start cap blew, I was getting a voltage reading across T2 ~T3 of 400V. Interesting.. .thats high voltage territory. Humm.

in the High-Voltage setting it is 2.3Ω between any two combinations of T1,2,3

So based upon the voltages I got from my attempt prior to the start cap blowing in my previous tests, I got
So in summary with the Steelman configuration it is wired to handle the high voltage across T2~T3

238.5V T1 ~ T2 = 0.9Ω. Same as the standard low voltage connection above, since it is the same connections.
296.8V T1 ~ T3 = 1.6Ω (two coils in series)
399.9V T2 ~ T3 = 2.3Ω Same as the standard 3 Phase HV connection.

The low-Voltage option with the run capacitor would not be, if I’m not mistaken.

Going back to the first thing in the Steelman manual: "it is important to remember that T1 and T2 two lines will be carrying more amperage than the nameplate of a three phase motor will indicate. This is true because it will be carrying the same total power on two lines that it would be carrying on three lines when operating on three phase. The current required from single phase lines times 1.73 delivers the same power as three phase provided that the system efficiency and power factors are the same.”

Thoughts?
 
The thing about static and rotary phase converters (basically the same thing) is
that they are trying to generate the 3rd phase by using capacitors. This scheme
requires a balancing of the phase angle and voltage by of the 3rd phase by
varying the value of the capacitors. Unfortunately, a well-balanced converter
is only balanced at a certain load. This requires a trade off.

I built a rotary phase converter and did a lot of tuning. In the end I got it
pretty well-balanced but only with my lathe running but not cutting anything.
When I would cut something, the balance would shift. This shift and the
corresponding loss of horsepower is the price you pay for this method of
generating 3 phase.

Another thing, you don't mention a start mechanism. That generally
requires another capacitor and a current sensor or timer.
 








 
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