Balancing transformer help needed

[Tom Reed]

I have transformer and am looking for info on it's suitability to to use as a balancing transformer with a ST-5 powered by a 6/1. It is a HS12F2AS 2KVA transformer MFG by Sola Hevi Duty. Here is a link to the MFG's page http://www.newark.com/sola-hevi-duty/hs12f2as/auto-transformer/dp/52M9859

If this is a suitable transformer, any suggestions how to wire it?

Here is a schematic:

[DanG]

Temperature Rise 115 Deg C on that model... mount it carefully.

Some light reading here: http://64.90.169.191/applications/electrical/energy/trans_efficiency.html (cant find smaller xfmr notes, sorry)

Anyhow, I know its probably a little late but searching for a used copper-core 1:2 up/down transformer would be my choice, over sized too...

[mike90045]

Well, you have a 5Kw generator, and a 2"kw" balancer.  You won't be able to completely pull full load off a single 120V leg, but you should be able to come close.

Check out the diagrams in the Xantrex/Trace T220/T240 Transformer manual. That should help.
http://www.altestore.com/store/Enclosures-Electrical-Safety/Miscellaneous-Electrical-Parts/Transformers/Xantrex-Trace-T240-Transformer/p2259/

http://www.altestore.com/store/Enclosures-Electrical-Safety/Miscellaneous-Electrical-Parts/Transformers/Xantrex-Trace-T240-Transformer/p2259/pdfs/xantrex/T240%20Autotransformer%20User%20Guide.pdf

I need to be careful with my 240V - 24V sprinkler timer transformer, that it does not attempt to work as a balance transformer.

[Tom Reed]

Ok realizing that only 2 kw of of the 2.5 theoretically available kw, but we are engine limited to 3 kw so that doesn't seem an issue. The next issue I see is which set of windings to use if using the secondary windings it would be neutrals to x2 & x3 with the 120v hots going to x1 and x4.

Any thought about using the primary vs. secondary windings?

[gregger2k]

Tom,
I would use the secondary windings.  Use the '120-0-120' configuration. Hook the neutral to the X2-X3 connection and the 120V legs go to X1 and X4, and do not connect X2 to ground. You will then have a big auto-transformer. I have a 4KW torrid hooked up this way and it works great to even out the current between the 120V legs.

Greg

[gregger2k]

PS: You could also possibly hook up the primary as well for more copper but I would be concerned about winding imbalance. You probably would just saturate the iron anyway.

[bschwartz]

     "neutrals to x2 & x3 with the 120v hots going to x1 and x4"

That is how I have mine hooked up.

[Tom Reed]

Ok thanks for the confirmations! I'll try not to let the magic smoke out.

[gregger2k]

Do you have the number for 911?
Or know of any firefighters in the area?

[Tom Reed]

It works, but not well enough. It seems I'm power limited due to lack of HP on the listeroid. The acid test is running the microwave on full power, which it will now do, but just barely. Voltage on the microwave leg goes to 105 and the other managed to stay around 115. The fundamental problem is that the inverter on the microwave leg will back off on it's charge rate to 0 how ever the other leg is still chugging along at a full 13 amps. This does not free up enough power to run the extra load. The microwave is about 16 amps and who knows what the power factor is.

So on to plan B. Unfortunately this transformer is probably not big enough. If the generator is wired for 120vac only and it's run through the 240vac primary windings, the 120 vac taps on the secondary winding should have 60 vac and having gone through the transformer might be clean enough to rectify and send to an MX60?

[gregger2k]

Tom,
Do you have any 220v loads on your system?
It might be easier to wire everything to 110v and change your outback stacking setup.

I could loan you my auto-xformer to try but it does sound like you are power limited with 1 outback using that much charge current.

Greg

[Tom Reed]

No 240v loads at this time, but a good wire feed welder is in the plans, also might change the pump for the water system to 240v.

I really think I'd like to make a good 48vdc charger for the battery bank. That way the generator can be run at optimal load no matter what the demand for the system is. Are there any good reasons not to go this way?

[gregger2k]

Charge control is the biggest difficulty with a ST head (but you knew that already).
I hear you can just hook up a rheostat and you are good to go

If anyone knows of a source for a big 48VDC alternator, or one that can be modded to 48V I would also be interested.

-Greg

[gregger2k]

Something like this  http://www.weirdstuff.com/cgi-bin/item/22081 might be a good way to go.
Wide voltage range input and regulated output. Hook it up directly to the 220v windings and no imbalance!

I remember someone documented what bins to jumper to power it up. I will try to find the information.

-Greg

[bschwartz]

Greg, if you find that info, ill buy you a bunch of beer!!!!
I bought one of those a year ago, and never got it working.
The seller was no help.