Rectified 3 ph possible or not to do.

[r77]

Hi everyone

Can I take two 230 feeds from a three phase 400/230 volt alternator, one live from each phase and use the common neutral / centre of the y
and put both lives through a bridge rectifier and from there take the DC out to feed an inverter, or can I go as far as to take a 230 volt feed from all three phases
and the common centre of the y and rectify them to feed an inverter.

Bottom line I have a three phase alternator, and do not want to buy a single phase of the correct kva rating, and am hoping I can harness either 2/3 of 3/3 of
the power my 3ph alternator already has, rectify it to dc and use it to heat water in dump load mode or feed an inverter charger in standard mode, it is 10kva
6 wire three phase, I either have 230 volt or 400 volt, have not seen the alternators terminals yet so unsure if there are more reconnection oportunities, the
plate says 230/400 volt, and the diagram shows 12 wires, though on most set if this was the case you would have more voltage options on the plate.

Any help would be much appreciated

Thank you kindly, john

[r77]

Here is a schematic of the alternator in question, it is a Mecc alte BTO3, transformer controlled 3 ph,
230/400 volt y connected setup.

[Tom Reed]

Hello John, I think the lack of replies is that we aren't really sure what you're asking. If I understand correctly you want to run the generator to power a water heater? The most efficient way to do that is to put a 3ph element of the correct size in it. If for some reason you want to run it on dc than there are 3ph rectifiers that will do the job and are not expensive.

[r77]

Thanks Tom

To simplify things, will this work

[r77]

Im only susing out whether or not this will work,
I will be connecting the generator to an inverter charger that can load share, this way when I need to top up the battery bank, I can start the generator and charge them, this will initially take a lot of currenrt, but when this initial charging phase is done, the generator would be wasting fuel while the batterys are topped off and conditioned, and it is at this point the dc rectified current will be used to heat water while the batterys are being topped off, this way the engine is kept loaded heating water. I could let the inverter charger actually heat the water instead of using the dc to do it, but I want this DC circuit as a backup incase the inverters power sharing gives bother, or I come across a cheap inverter that does not have power sharing.
Im only trying to grasp the principles of this, and will test as I go along.

[Tom Reed]

Ah I see, said the blind man, as he picked up the hammer and saw. I use an electric water heater as a "dump" load for my PV panels when the charger goes into float mode. The outback MX60 has a relay that can be set to close when it enters float mode and that turns on inverter power to the water heater. It's got 240 v elements running on 120 v so it only uses 1175 watts.

Newer controllers like the midnight classic will do PWM of the dc to a load so you could rectify the entire genset output to dc, send it to the midnight classic and let it take care of charging the batteries and diverting any extra power to the water heater.

[r77]

Thanks again Tom

Glad someone understands my problem. The pheonix  inverters I looked into a year ago, do the load sharing thing, they are disigned for boat owners, who sometimes have
shore power, ie, mains, and a genny on board, the idea being one assists the other and shares the loads, one being charging, the other being whatever you have your inverter
plugged into aside from the battery bank.
The reason I do not rectify the whole gennys output is and feed it to the inverter is that the voltage I am currently messing with is too high, 230 ac rectified is 325volts and
finding an inverter that wants that may be a challenge, its safer for me to dump it to heating via the programable relay on the inverter or a current relay.

I will look into the inverters you mention, sometimes the brands that are populare in the US are not to be got here, anyway, plenty of experimenting and planing to do first.

[r77]

Thank you Tom, I have taken in all I can and will be proceeding with caution, the high DC voltages involved here have concerned me all along, and I do not plan putting this into operation but may impliment it as a test case.

I am now questioning the fesability of using a transformer based AC Welder rectified to supply a charge controler / inverter, below is a link to this post, I hope someone will once again take on my many questions, and in return hopefully help a lot of others who are consideing exiting the controlled sanctioned taxed to the hilt existance our so called governments are pushing down our throats.

Below is a link to my new idea, an 80 volt 180amp output welding transformer, which will keep the voltages quite low.

http://www.microcogen.info/index.php?topic=3460.0

Many Thanks to all.

[Tom Reed]

IIRC The midnight classic charge controller will take 600 vdc. Your rectified 3Ph will be a little over half of that. No extra transformer required.

[mike90045]

IIRC The midnight classic charge controller will take 600 vdc. Your rectified 3Ph will be a little over half of that. No extra transformer required.

There are several different Midnight Classic models, 150, 200, 250 (volts)
http://www.midnitesolar.com/products.php?menuItem=products&productCat_ID=21&productCatName=Charge%20Controllers%20-%20Classics
the high voltage controller ( 600V ) are made by Morningstar and Schneider Electric, and cost a fair amount more then the Classics