Generac 3 phase to 1 phase?

[bobzell]

I have a Generac model 6032-3 generator powered by an Onan CCKA-MS two cylinder air cooled motor. The altenator head is belt driven. The tag on the alternator indicates it makes 115/230 Volts 3 Phase 9KW 22.6 Amps at 3600 RPM. Exiting from the bottom of the altenator I have two metalic shield bundles: four wires in one and five in the other and two aditional wires with no shield for a total of 11 wires. Every thing I read about changing phase on an altenator refers to either 8 or 12 wires.
Here is how the bundles break out:
Bundel 1 has four wires labled 1,2,3,55.
Bundel 2 has five wires labled 00,11,22,33,44.
The two non bundled wires are labled 17 (blue) and 16 (orange) all the bundled wires are gray.
Does anyone know if/how this alternator can be configured for single phase 115/230. The motor runs very strong and this unit would be just the size I need for standby power at my house.
Thanks
Bob

[EricWood]

Sorry I can't really answer your questions directly, but here is a link for obtaining a manual for your model. About $7.35.


http://www.m-and-d.com/GEN-046055


Not sure if it will have the info you're looking for.


eric

[FarmallJeff]

Hi i am a bit confused its states 115/230 thats single phase 3 phase would be 208/277/430 Have you tryed running it and checking it with an amp meter to see what you out put is ? it sound like it wired for single phase now ?
JEFF








I have a Generac model 6032-3 generator powered by an Onan CCKA-MS two cylinder air cooled motor. The altenator head is belt driven. The tag on the alternator indicates it makes 115/230 Volts 3 Phase 9KW 22.6 Amps at 3600 RPM. Exiting from the bottom of the altenator I have two metalic shield bundles: four wires in one and five in the other and two aditional wires with no

[FarmallJeff]

Try this link it has circut diagrams

http://www.3phasepower.org/3phasewiring.htm

[Jim Rankin]

Jeff,
There's a 3 phase connection that produces 120/240 (or 115/230). It's called series delta. Takes a 12 lead generator to do it because one of the phases (sides of the triangle) is tapped in the middle (at the series connection) for a neutral.

So you have 3 lines and a neutral, but unlike the Y connection, either of the lines next to the neutral tap will show 120 when measured to the neutral and the line to line voltage is 240 in any combination of 2 lines. (L1-L2, L1-L3, L2-L3) The kicker is there's a line (commonly called the Stinger or B phase, red leg etc.) that is ~208 to the neutral, so you can't use it for 120 volt circuits obviously.

bobzell,

If you can't reconnect from a diagram, I would use the 2 lines and N that produce 120 L-N and 240 L-L as my single phase lines and expect to safely get a little more than 2/3 of the full kVA output from the set connected just as it is. Just insulate the B phase and don't use it if you have no need for 3 phase.

[Wayne 440]

It is probably a 230v delta wound machine with a center tap neutral on one phase. If that is in fact the case, you already have a single phase output available at about 6kw. Check it with a voltmeter each phase to "ground"- if the readings are roughly 120-120-208 volts you can be 99 percent sure that you have a delta wound machine. The two 120 volt leads and neutral will be used for single phase.

Incidently, your amp figure doesn't make sense with a 9kw rated machine. Are you sure it isn't "26.2" amps?. That would be right at 9kw 3 phase.

[bobzell]

Thank you all for the help! Your post have given me new paths to follow. Wayne is right. The amps should have been 26.2 not 22.6 my bad. I have not connected the alternator to the motor yet because the leads are not terminated to anything. Today I am going to ohme them out and make a table that might shead some light on construction of thei unit. Then I will bring the leads out to terminal block and connect the alternator to the engine and measure voltages. I will post the results. I was happpy to find the manual at m&d but it will not arrive untill next week. Just another note. I neglected to mention that the leads marked 1,2 & 3 were caped and not conected to anything. I am speculating the Blue and Orange wires no. 16 & 17 might be a 12V output? That would leave me with five leads used in the confiuration I found the unit in 00,11,22,33,44,55. Still somewhat confusing, but pushing back my vail of ignorance has never been easy!

Moving forward carefully.
Bob

[bobzell]

OK mystery solved. I terminated the wiring on a barrier strip and o-scoped the output. This thing only makes 3 phase. The 115V output and the 230V volt output are three phase. Why would you want 115V 3 phase!?!

Here are the pin outs.

16 & 17 go to the brush. These might have been conected to a external regulator.

115V 3 phase is on 1,2,3 (load) & 00 (neut)
230V 3 phase is on 11,22,33 (load) & 00 (neut)

Leads 44 & 55 are used as part of the regulator ckt?

Well anyway I have strong Onan CCKA-MS out this deal. Can anyone recomend a good 10KW belt driven alternator?
Thanks to each of you for your assistance.
Bob

[pegasuspinto]

It looks like to me you have a normal 3 phase Y setup
i drew up a little diagram to show how i believe your gen is hooked up, check it with an ohm meter to see if it works out

3 phase voltages are all based off of 115 volt(or multiples of 115 volt) windings stacked up in different orders and combinations.

if you fire it up and measuere between 1 and 2, 2 and 3, or 1 and 3, you should find about 208 volts, if you measure it betweem 11 and 22, 22 and 33, or 11 and 33, you should find 430 volts.

you can hook this one right up to your house in several different ways, you can hook 00 to netural, and pick two out of 1, 2, and 3 and hook those up to the two 115 legs. one of those 3 is left unconnected..or perhaps run it as a seperate 115 outlet in the generator house. all your 115 outlets will still be at 115, and the 230 appliences will be running on 208. if you check the data plates on your 230 volt equipment, you will often see it rated for "208 to 240 volts", this is because buildings wired in 3 phase will sometimes do just what i am telling you to do. anything with an electric heater will run at about 87% of the wattage at 208 then it would run at 240 volts, but that's not a bad thing, as it will cut down the stress on your generator a bit, and you'll really not notice that bit of loss. my gen's regulator is set to run about 125 volts right now, a bit hot but within range of most anything that is a 115 volt device, but it puts my 240 volt setup at around 230 volts actual. if you can isolate 00 from netural, you could run 1, 2, or 3 as netual, 00 as one 115 leg, and the outer leg off your netural (for instance, 00 1 11, OR 00 2 22, OR 00 3 33)
that kinda complicates things a bit, also the open legs will be running somewhere in the 300+ volt range above netural, and you really couldn't use them for anything safely. (if anything above looks wrong to anyone, let me know, and i'll edit this...don't want anyone in danger)

as a side note, you should be fine overloading this set on the amperage a bit, the amps the legs are rated at are the watts devided by the volts devided by the phases. you can go over the amp rating a bit, as the real enemy is the heat, this results from the total wattage it runs. if everything stays cool, you have no real problem (no, don't try to do this with your electrical inspector present) i've had mine at over double the amp rating without anything running even a bit hot, it was still within the total watt rating of the set. your milage may vary, your electrician will be in convultions and fits, OSHA, UL, FBI, and PETA will all be on your doorstep soon

Rob

[Jim Rankin]

bobzell,

Wow, it really is 115 and 230, just not in the normal way!

Okay, now clarify whether the 115 and 230 are L-L or L-N measurements!

If you are quoting L-L measurements and you get 230 on the 11,22,33, you should get 133 or so from any of these lines when you measure to neutral. This could work as a backup using any two lines and N as your single phase source. And as mentioned, you could load all three lines if you set up a 3 phase distribution panel and plug cords into it so you balance the load over all 3 phases. It's just hard to do this if you use a transfer switch to connect to a single phase house etc.

You might want to load it with an electric range or space heaters, hot plates, blow dryers, light bulbs etc to see what the regulation does when it's under load. If you're missing the regulator, it may drop too low under load or maybe not? Any voltage on the other leads? 44 and 55? What do the brushes run on? sliprings or commutator with segments?

Pegasuspinto,

I would not recommend isolating 1 leg of a 3 phase set as you mention in your last proposal. For one thing, it would cut the output way back even compared to using 2 lines and neutral for single phase "220". He's only got 9kW 3 phase to start with.

Most small appliances and tools these days are rated for 120 to 125 volts and should do fine up to 130 volts. In fact depending on where you are along the transmission lines out in the country, our utility voltage runs 125 volts +, and it does shorten the life of incandescent bulbs quite a bit. So we buy "long life" bulbs which are rated at 130 volt instead of 120 or compact fluorescents.

For a 3 phase wye connection, the voltage between 2 lines is always 1.732 (square root of 3) times the voltage between any line and the neutral. Vary one by changing the regulator setting and the other varies proportionally.

On a standard low voltage (parallel) wye connection, this could range from 110/190 120/208, 127/220, 130/225, 133/230, 139/240 as you adjust the regulator. For the standard high voltage (series) wye connection, the voltages are in the range of 230/400 to 277/480. Where you set the voltage depends on your needs and on where you are located and whether you are matching a 50 hz or 60 hz power grid with your backup generator. Volts/hz ratio is important in things like electric motors.

Your explanation of amperage rating is pretty much a quick brush by the real situation. To calculate the amperage of a 3 phase set (if it isn't on the tag
***Not kW***, but kVA x 1000 = VA divided by 1.732 divided by line-line voltage = amperage.
example 100kVA X 1000=100,000 VA/1.732/208 volts= 277 amps

Or kVA X 1000 = VA divided by 3 divided by line-Neutral voltage = amperage.
example 100kVA x 1000=100,000 VA/3=33,333 VA/120 volts=277amps.

Single phase kVA X 1000 = VA divided by line-line voltage = amps per line.

Why not use kW?
kW is the measure of engine POWER, and determines electrical POWER capacity but not amperage. The amperage of that electrical POWER depends on the power factor of the load. It may be an "easy", low power factor load like a lightly loaded motor, or a "hard", high power factor load like a bunch of electric strip heaters. In either case, the same amperage limit derived from the kVA rating applies because as you say, amps or current is what causes the heating in the generator windings.

kW or watts or real power is what causes the heating in the engine driving the generator, so kW and kVA are two different things that look alike and sometimes are equal numbers, but tell you 2 different things about a generator set.

[bobzell]

I must say I am impressed by the depth of knowledge displayed by contributiors to this forum and touched by their willingness to share that knowledge.

Here are my thoughts about my decision to abandon this alternator head for this project:

The output of the alternator would be less than what I need unless I could tap very near the full rated output (9KW).
The unit will be hooked to the house through a manual transfer sw so balancing the loads might be a problem. I can't imagine trying to explane "blanced loads" and saying, "Don't plug that in there!" to "she who must be obeyed" while we are all experiencing PHSD (Post Huricane Stress Disorder). If it was just "us guys" I think I would go ahead and use it.
Fuel efficiency is a issue when running a 16HP motor to make <9KW of power. I plan to convert the motor to LPG and use a 250 Gal tank. This should give me plenty of run time and eliminate the need to find fuel in a crisis situation.
I would need to construct /purchase a regulator to obtain consistant output adding to the complexity and delay of the project.

So now I'm looking for a diffrent alternator head. If any one wants this one email me and you can have it. I would still like to know where 115V 3 phase power might be required? European applications?

Thanks
Bob

[pegasuspinto]

this gen is -not- 3 phase 115, it's 3 phase 208. the power from netural to the legs is 115, the power ACROSS the legs will be 208. with it set up like that, netural connected, you have no need to balance any loads

also, a 16 horse motor can make only 12kw of power, assumeing 100% efficency in conversion. you're going to loose some horsepower converting it from gasolene to LPG, between that and inefficency (if you have to belt drive the new head, you will have considerable friction loss), you're going to end up with a generator that can't even make 9kw

just my 1 cent

Rob

[bobzell]

I beg to differ Rob. The Generac ID plate is stamped quite planly 115V/230V 3phase. In additon I have lately been sent a Generac drawing NO.46057 that shows my alternator hooked up to something called a reactor box and a optional control panel no.5984. The wires coming out of the altenator in the drawing and the wire markings on the altenator I have are identical. Also my o-scope test yeterday proves out the drawing and the pin out I described yesterday. The man who supplied me with the drawing said he had encountered a unit like this one as the power source for a bucket truck of the type used by the telephone company. He did not recall the manufactuer of the bucket. What we have here is some kind of very specilised alternator obviously directed at a very small market. I have never seen 115V 3 phase. Untill now. But here it is clearly shown in the drawing 115V 3 phase can be had on leads 1,2,3,and 00. And 230V 3 phase on leads 11,22,33 and 00. And here it is sitting in my shop floor. I sure don't know everything. But I do know I have never seen anything like this before! I still dont know why anyone would build such a odd powerplant. Just to make it worthless if stolen? Seems like a lot of trouble to go to.

Thanks
Bob

[Wayne 440]

Several models of Telsta brand aerial lifts use 3 phase for lift motors. However, all of them I have seen were smaller than 9kw, and most were Onan branded sets as well. 115V 3 phase was common in the WW2 era for searchlight and fire direction control units, radar antenna positioning etc. The same turret that rotates a good sized AA gun would turn a bucket, so maybe that technology crossed over.

[K D Redd]

I have access to several 60's era military generator. They all have provision for a 115 volt 3 phase. I was told this was a delta connection. I was also told there were power tools at military surplus auction that required the 115 3 PH. All of the info. is VERY second handed. I also wonder IF the 115 3 PH delta with no grd. return needed and used on power tools was to enable the uses of said power tools in wet location with less danger than normal equipment.

WONDERING
Kent

[Jim Rankin]

Kent,

I don't know how much safer it would have been, but it could have been used as an ungrounded delta source so that a phase shorted to ground (the first one) would not prevent operation. Might be handy when the manlift bucket was up in the air with someone in it. Nice to be able to get it down or even finish the job before tracing down the fault. The problem with these systems is when the second phase shorts. then there is current flowing from fault to fault. Some industrial plants are wired like this, and have fault detectors on the system.

the 3 phase motor doesn't care whether the 3 phase generator or transformer connection is wye or delta.

[Steve Dawkins]

Regarding 115V / 3 phase, I heard that type of power is/was used aboard ships. It allows for a balanced 3 phase system among 115 volt loads, and keeps the power isolated from the ship's hull to reduce electrolysis.

[pegasuspinto]

if this is truely a 115 volt 3 phase, it seems to me you STILL have 6 115 volt windings inside. open it up and lead out all 6 windings individually, and you will have a 12 lead reconnectable generator.

Rob

[bobzell]

Hello Rob
What you say is true but a bit outside my comfort zone. I have never dug into the inside of an altenator.
Thanks
Bob

[bobzell]

Hello Rob
What you say is true but a bit outside my comfort/ability zone. I have never dug into the inside of an altenator.
Thanks
Bob