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Author Topic: Indian Head to 110v only???  (Read 11102 times)

biobill

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Indian Head to 110v only???
« on: November 18, 2006, 01:27:03 AM »
  I went to convert what I thought was my ST3 head to 110v only and got a big surprise. It Ain't No ST. Two extra diode bridges, an extra slip ring, coupla series fields what ever they are. Does anyone know if this thing can be changed to 110V only? Worth doing? Is it like the ST's in that it will only deliver half it's rated watts on one leg? Possibility of transforming 220 to 110?  Need some ideas from sparky types
     Thanks, Bill
Off grid since 1990
6/1 Metro DI living in basement, cogen
6/1 Metro IDI running barn & biodiesel processer
VW 1.6 diesels all over the place
Isuzu Boxtruck, Ford Backhoe, all running on biodiesel
Needs diesel lawnmower & chainsaw

Doug

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Re: Indian Head to 110v only???
« Reply #1 on: November 18, 2006, 02:13:39 AM »
Ah a real good question and I'm glad this was brought up.....

Indian heads, the cheap kind that is are actualy inside out compared to the ST design. the field is stationary and the armature has slip rings that you draw your power off. This is an interesting way to build a syncronous machine because it affords some advantages to the DIY as well as disadvantages.

To answere your question first, if it has 3 slip rings and was designed to give you 120-neutral-120 for an Edison three wire system then I'm afraid no your stuck with that unless you buy a transformer but on the upside you now have a series fieild that self adjusts your output for increasing load more or less. Reactive loads play havock with this system so try and keep your loads near unity as possible for best voltage regulation. And yes you will only be able to draw 50% load on one half of the winding.

Realy you shouldn't wire anything 120 only if you can avoid it. Run as many of your loads 240 so your copper losses are lowest and try and ballance your 120 v loads to keep the neutral current low.

This is how the original SOM heads were built but with all the goodies removed. With this type of alternator a savy builder can combine a generator, a starter and battery charger all into one unit but sadly the Indian don't do this. Alternatively this type of machine could be built as a generator and inverter with the addition of a commutator assembly so you could run an engine with 3kw of shaft power and a large battery bank for suplimental power ( charged by the head of course ) and have a higher output for short perioids of time say 6 kw. But again India doesn't build these.

So inconclusion no your screwed and stuck with Edison 3 wire and we're all screwed out of a head with more potential than we can get in its delivered form. Last but not least they also tend to be a little more work, you need to watch the slip rings and brushes keep them clean and smooth for best opperation.

Doug

biobill

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Re: Indian Head to 110v only???
« Reply #2 on: November 18, 2006, 03:11:50 AM »
I was afraid of that.
  The house is solar electric and, since my inverter puts out 110v, thats the way I wired it. Probably isn't code, bit I just connected the two legs in my load center and fed it with 110. So... seems I've got a problem. If I send one leg to the battery charger  and the other to the load center via gen transfer relay, that's not exactly balanced, is it.
  Will a stepdown transformer solve my problem? I'm completely in the dark here, are they expensive? Is it  a rational solution, or should I think about another head. 
Off grid since 1990
6/1 Metro DI living in basement, cogen
6/1 Metro IDI running barn & biodiesel processer
VW 1.6 diesels all over the place
Isuzu Boxtruck, Ford Backhoe, all running on biodiesel
Needs diesel lawnmower & chainsaw

Doug

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Re: Indian Head to 110v only???
« Reply #3 on: November 18, 2006, 03:37:08 AM »
Hmm.....

Well 3000 w isn't much and I do have a quick and dirty trick. Find any transformer with a 120-240 primary rated at 6 kva ( even a more comon 5 in a pinch of you don't push it to hard too often above its rating ). Wire the primary to your head 240 and use it as an auto transformer by taping power off only 1 of the two sets of primary coils. The secondary is of little or no use to you so insulate the leads and ignor them. I have no idea where YOU could find a transformer that size and shipping from here is likely not an option even if I scavange one up for you.

There are 120-240 transformer available but I can't say the cost. Check Hammond, Marcus ect on line...

Double check your head only 3 slip rings not 4?

4 slip rings and your good to convert to 120....

Doug

biobill

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Re: Indian Head to 110v only???
« Reply #4 on: November 19, 2006, 10:16:35 PM »
  OK, transformer it is. I'm looking at a used one rated a little over twice what I need (3KVA). Any problem with that (other than weight :P)? i.e. inefficient at part loads etc. The portable ones with the plugs look like they might not hang in there for the long haul. Any info on what to look for, and what to avoid, in a transformer would be greatly appreciated.
                                            Bill
Off grid since 1990
6/1 Metro DI living in basement, cogen
6/1 Metro IDI running barn & biodiesel processer
VW 1.6 diesels all over the place
Isuzu Boxtruck, Ford Backhoe, all running on biodiesel
Needs diesel lawnmower & chainsaw

Doug

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Re: Indian Head to 110v only???
« Reply #5 on: November 21, 2006, 11:20:05 PM »
No Issues I can think of.

I was looking at a 10 kva Westinghouse unit Saturday and thinking about you....
Its intended purpose is to step 600 down to 120/240 and the thought hit me. How far is your power house from your home. If you can find a pair rated at 3 kva ( note this smaller size is possible because you can parralel the LV windings rather than auto transform with the bigger unit ) you may wish to consider running 600 or 480 from you power house to your home. This offers some advantages, like smaller cable from your power house and a local ground directly at your inverter and main service. The transformers will also act a little like a filter and clean up a small amount of distortion if you have any.

As a side note there will be a slight drop in efficiency because some energy is wasted inthe iron and copper. Transformers are the most efficient electrical device because it has no moving parts and the magnets flux is tightly coupled as compared to a rotating machine like a motor. Obviously the losses remain about the same from no load to full load so the closer you come to running at full power the better use you make of your power system for the cost of generating it.

Doug

Doug

biobill

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Re: Indian Head to 110v only???
« Reply #6 on: November 22, 2006, 02:11:29 AM »
 My "powerhouse" is in my basement, about 18' from my load center.  Am I OK just getting a dry type, 440/220 X 220/110 in the 3 to 7.5 kva range or do the kva's need to be sized more specifically. Should I oversize it a bit? Chances are that it won't be maxed out much of the time.
                                            Thanks, Bill
Off grid since 1990
6/1 Metro DI living in basement, cogen
6/1 Metro IDI running barn & biodiesel processer
VW 1.6 diesels all over the place
Isuzu Boxtruck, Ford Backhoe, all running on biodiesel
Needs diesel lawnmower & chainsaw

Doug

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Re: Indian Head to 110v only???
« Reply #7 on: November 22, 2006, 02:37:51 AM »
Sory Bill I don't explain myself well do I ?

The reason to up size the transformer when using the Auto transformer connection is the wire size on the winding has to be large enough to handle the current.

Your basicaly oversizing the transformer to overcome the same problem as your head has. I wouldn't go smaller than 5 kVA, and I wouldn't ask more than 20 amps from it.

Lets assume for a moment your not going to exceed about 80% of your engine generators power in general duty. This makes good sence because your at a point where your engine should last longest and give best efficiency. A transformer is most effcient at 100% so by my math this is the limmits of where you want to be.

A larger than 5 kVA transformer will let you run at full power for longer peroids of time in Auto tansformer connection but you will pay a price of lower efficiency.

I feel like I'm talking in circles now, but I hope I have explained this better....

Again try and find a used industrial 5 kVA dry transformer with a secondary 120/240 ( marked X1, X2 --- X3, X4 ) the primary will be marked H1 and H2 the voltage doesn't matter you won't be needing this. Find some electrical contractors who do industrial work of comercial buildings ect. They may have a used one laying around you can get for a cheap.

If not and you decide to spend money on a new transformer then by all means get a 3 kVA 240 to 120  unit and your set with that too.

biobill

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Re: Indian Head to 110v only???
« Reply #8 on: November 23, 2006, 04:41:56 PM »
 Not your explanation Doug, my ignorance. I know just enough to make some really bad decisions. I understand the basics of how transformers work, one winding inducing a current into another which can be longer or shorter to change current and voltage. I don't know what the term "auto transformer" means. Sounds like you are using the windings from the same side to induce to that side.

                    480/240  X  240/120
                                       ^     ^
 Power in at the 240 pair and out at the 120 pair???  I don't get it I'm afraid, so...maybe you could explain some more if you happen to be in this neck of the woods. Use small words

                                                Bill
Off grid since 1990
6/1 Metro DI living in basement, cogen
6/1 Metro IDI running barn & biodiesel processer
VW 1.6 diesels all over the place
Isuzu Boxtruck, Ford Backhoe, all running on biodiesel
Needs diesel lawnmower & chainsaw

Doug

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Re: Indian Head to 110v only???
« Reply #9 on: November 23, 2006, 11:50:38 PM »
No problem Bill:

An Auto transformer uses one winding not two to raise or lower the voltage. In this case what  I sugested was to take a transformer with a windings X1 - X2 and X3 - X4 and connect them in series for 240 volts. Then where you have X2 and X3 connected connect your white wire, this will be your neutral. X1 or X4 will have 120 volts across it, chose one of these as your 120 volt line. The generator is connected to X1 ( line one ) and neutral to gound ( this is your generator neutral and your main system ground, you will have to disconnect this ground), your other line on the head will be connected to the last wire X4. Now X4 will become your new neutral and you will ground here and not at the original neutral in the generator ( this oart is important be sure you understand this ). When the generator is running all of it power is routed threw the 240 connection to the transformer windings and the X4 is your neutral and the point of connection between X2 and X3 is your new 120 volt power source. The windings will transform the 240 to 120 and give you full power but the 120 volt windings must be rated for 20 or 25 amps ( 5 or 6 kVA transformer ). The other terminals or wires on this theoretical project with a used industrial 480 or 600 transformer are not used.

This is a bit of hack job but it will work and it makes sence to try it if you can get a surplus or used one from an electrical contractor for less than a true 240 to 120 transformer new from a suplier. I could also probably get sued for this if you burn down your home and get hurt by taking my advice so I guess I better add you assume the risk for doing this yourself.

Price out a true 3 kVA 240-120 transformer and see what you can find.
Lastly be careful if your not comfortable with this don't do it.

Doug   

Technonut

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Re: Indian Head to 110v only???
« Reply #10 on: November 28, 2006, 03:40:39 AM »
I have a similar issue....  I have a Trace 4024 inverter and battery bank. The Trace 4024 has a built-in battery charger that is capable of throwing a 30 amp charge into the batteries. (which is what I want to charge the batteries as quickly as possible when using my diesel generator) The utility power comes in to the main panel box, which goes to a sub-panel box, and from there to the Trace 4024.

The Trace 4024 can only handle 120 volts going in. My 12.5 KW Isuzu diesel generator puts-out 100 amps @ 120v / 50 amps @ 220v. I need 30 amps for the charger, and at least another 10 amps to run the house while the batteries charge.

I wired the 120v from the generator to a 100 amp breaker in a panel box. I have a 60 amp breaker in the box that is wired to the Trace 4024. From what I gather, it is not "balanced" running the generator this way, but it has worked well so far. :)  (I do have the generator head grounded to an 8ft copper grounding rod with # 6 copper grounding wire. (not spliced) )

I found a transformer here: http://www.surpluscenter.com/item.asp?UID=2006112720341102&item=15-1161&catname=electric, but I am not sure of how many amps it is rated for. If it is the 25 amps that I have seen on other transformers, it would not do much good in my case.  :(

Any input would be appreciated...
Metro 6/1 (4 kW Indian GenHead)

GM-90 6/1 (7.5 kW ST GenHead)

Isuzu 3LD1 (12.5 kW Croatian GenHead)

Andre Blanchard

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Re: Indian Head to 110v only???
« Reply #11 on: November 28, 2006, 02:40:53 PM »
I have a similar issue....  I have a Trace 4024 inverter and battery bank. The Trace 4024 has a built-in battery charger that is capable of throwing a 30 amp charge into the batteries. (which is what I want to charge the batteries as quickly as possible when using my diesel generator) The utility power comes in to the main panel box, which goes to a sub-panel box, and from there to the Trace 4024.

The Trace 4024 can only handle 120 volts going in. My 12.5 KW Isuzu diesel generator puts-out 100 amps @ 120v / 50 amps @ 220v. I need 30 amps for the charger, and at least another 10 amps to run the house while the batteries charge.

That 30 amps into the 24 volt battery which will be somewhere around 28 volts at peak charge power, is only about 7 amps at the 120 volts (<1000 watts) into the charger.  Your 12.5KW generator is just loafing.
Are you sure the charger on the 4024 will only do 30 amps?
My 2512 says it will do somthing around 100 amps but I have only ever seen 50 amps, small battery pack and a small generator.  Trace chargers, at least the one in the 2512 are not power factor corrected and so for full power they need a very stiff line voltage.
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Technonut

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Re: Indian Head to 110v only???
« Reply #12 on: November 28, 2006, 03:33:46 PM »
I have a similar issue....  I have a Trace 4024 inverter and battery bank. The Trace 4024 has a built-in battery charger that is capable of throwing a 30 amp charge into the batteries. (which is what I want to charge the batteries as quickly as possible when using my diesel generator) The utility power comes in to the main panel box, which goes to a sub-panel box, and from there to the Trace 4024.

The Trace 4024 can only handle 120 volts going in. My 12.5 KW Isuzu diesel generator puts-out 100 amps @ 120v / 50 amps @ 220v. I need 30 amps for the charger, and at least another 10 amps to run the house while the batteries charge.

That 30 amps into the 24 volt battery which will be somewhere around 28 volts at peak charge power, is only about 7 amps at the 120 volts (<1000 watts) into the charger.  Your 12.5KW generator is just loafing.
Are you sure the charger on the 4024 will only do 30 amps?
My 2512 says it will do somthing around 100 amps but I have only ever seen 50 amps, small battery pack and a small generator.  Trace chargers, at least the one in the 2512 are not power factor corrected and so for full power they need a very stiff line voltage.



Thanks for the reply. I found that the highest I can set the 4024 charger for is 35 amps. At least I have it maxed-out now. :) I have a 16 batteries in my bank, and plan on adding 4 more shortly.

I originally had a 10 KW gas generator that had 25 amps available on 120v. It would immediately throw a breaker when it was hooked-up to the inverter no matter how low I set the charging amps. I then tried a 6.5 KW air-cooled diesel generator that had 30 amps available on 120 V. It did not throw a breaker when hooked-up to the inverter, but the inverter refused to switch over to the output. :(

The current radiator-cooled 12.5 KW Isuzu switches power over and charges fine.  :) 

Am I hurting the generator just running 120 V out of it? I saw this post, and was wondering if I would be better off running 220 V to a transformer, and 120 V from it to the inverter. The only thing that concerns me is having enough amps from the 120 V output of the transformer to the inverter to run the charger and house loads.

Metro 6/1 (4 kW Indian GenHead)

GM-90 6/1 (7.5 kW ST GenHead)

Isuzu 3LD1 (12.5 kW Croatian GenHead)

Andre Blanchard

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Re: Indian Head to 110v only???
« Reply #13 on: November 28, 2006, 06:25:34 PM »
The current radiator-cooled 12.5 KW Isuzu switches power over and charges fine.  :) 

Am I hurting the generator just running 120 V out of it? I saw this post, and was wondering if I would be better off running 220 V to a transformer, and 120 V from it to the inverter. The only thing that concerns me is having enough amps from the 120 V output of the transformer to the inverter to run the charger and house loads.

I would not worry about it with that generator.  You may want to check the manual I have seen some generators that had the center tapped 240 volt winding to get the two 120 volt windings but one of the 120 windings was made with larger wire so that if you used that circuit you could pull full power at 120 volts.  I other words the generator was designed to be run with the 120 windings as far out of balance as they could get.
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Tom

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Re: Indian Head to 110v only???
« Reply #14 on: November 28, 2006, 08:15:04 PM »
I had a sw2512 that and ran the charger from an Onan 6.3kw Onan LP generator. What I did to balance the load was to run the inverter/charger off one side while charging and the house load off the other. After shutting down the generator I would switch the house load back to the inverter. Not an ideal solution, but it worked great for the long term outages we endured at that location.

The best solution is go get another sw4024 and wire them out of phase, then you can charge your batteries faster and keep the load in balance. Your sw4024 should be drawing 35 amps and is charging your battery bank at 175 amps.
Tom
2004 Ashwamegh 6/1 #217 - ST5 just over 3k hours.