230-240v alternator : where to get one??

[mike]

I need a 230-240v alternator does anyone know where to get one of these puppies? I looked on trademe but no luck.

[curly12]

What sort of amps does it need to develop???

[mike]

13-21 amps is what im looking at or 3-5KW. just sent an enquiry off to china to hard surfing for it local. see what they come back with.

[UBZ]

I'd try searching for a generator. 1-2kva units are quite small these days . But output will be rpm dependent

[chrome]

just run 20 truck ones

[sibainmud]

Try Webster Group up here in Aucks. They are gene experts, or if you need to get one re-wound City Rewinds, Auckland. I deal with both of them all the time with getting marine gensets repaired. Some times there are different ways of reulating them, the most common these days is with AVR's (auto voltage reulators)
Hope this helps.
Cheers,

[Damz]

just run 20 truck ones

[Gofer]

I had my Golf Ute alternator modified to run a welding machine for mobile work. Fitted a diesel fast idle cable to keep the rpm at 1200rpm minmum and off i went repairing breaks on construction machines.....havnt seen this ever again.

[sibainmud]

I assume you are after AC? 220-250 volt is the easy part, 50 htz is the hard part.
Takes hours of setting up the rpm under full load.
Then watch the cycles go through the roof with no load
Done a few boogie installs and seen heaps of appliances blow up
Best of luck

[safarifern]

Best to look at Marine. Volkswagen marine do a 3.5 KW and a 5 KW. But as sibainmud said, getting the load right is hard. You need some decide load to get the amps up I would recommend you have a pulley set up to crank the RPM up at the gen end. Can I ask what you need such power for? You can do a lot with a 12V battery set up and a decide Inverter? Also Ebay is your friend, quite a few come though. Links below for new

Any other electrical help give us a shout

http://www.vw-m.de/index.php?id=368&L=1
http://www.machinemart.co.uk/shop/produ ... alternator

[Landynut]

yes i believe it largely depends what you are going to run off it.... if you need 50hz a pure sinewave inverter might be better, they go up to 5kw but the price is right

you dont want to be running sensitive gear off a modified sine wave, bad things will happen

I thought alternators were AC to begin with???
AC = alternating current ?

[safarifern]

Your right they do, its the diodes that turn AC to DC in an alternator for a car

Also agree with the "sensitive gear" comment, can be real hard to smooth your AC power gen so when RPM goes up and down you don't get spikes / low power .... really depends on what your using it for.

[rangimotors]

any reason he couldn't run it through a UPS with a battery? That should smooth out everything and charging the battery should give a good "dummy load" when not running anything from it. Although I would probably eat my words because a high amp UPS is pretty expensive...

[safarifern]

UPS is only designed to give power for a limited time, thus with continue use it will just burn out ... all a UPS is an inverter with a few large capacitors and relay to switch over from 240V source to 12V source when your 240V is gone ... and yep your right too, a 13 to 21 amp is big bucks! You can get an inverter for cheaper now days, but a 20 amp one which will be 240 x 20 = 4800 Watts is still a lot of $$.

[rangimotors]

UPS is only designed to give power for a limited time, thus with continue use it will just burn out ... all a UPS is an inverter with a few large capacitors and relay to switch over from 240V source to 12V source when your 240V is gone ... and yep your right too, a 13 to 21 amp is big bucks! You can get an inverter for cheaper now days, but a 20 amp one which will be 240 x 20 = 4800 Watts is still a lot of $$.

depends if you get an inline UPS or not. They will drop/increase voltage as required. I run a small (bunnings) generator through an inline UPS so that it's nice clean power.

[safarifern]

Oh OK so your using yours as a "Cleaning machine" for clean power out. A good idea if you have continues power I.E from a gen but if your going from battery the conversion from 12V / 24V to 240V will heat up circuitry quite a lot thus may have the "burn out" problem. Your set up sounds good, what sort of Watts do you get out of the gen? Petrol I take it? Quite loud or not to bad?

[rangimotors]

Its only a small cheap and loud generator, i built the set up when i didnt have power after a week from the earthquake damage. Fiunny enough i got power back the day that i built the system. I get about 1000 watts but my UPS can only "clean up" 650 watts at a time. I have been thinking about buying a decent sized ups and 4 stroke generator at some stage soon and bolting it all together on a portable trolly to take away where ever i need it. I have also considered ditching the tiny (12v 6a/h) battery that comes with the UPS and wiring up a few camper van batterys so that I don't have to run the generator all the time and can run the generator until the batteries are charged and then get 5-6 hours out of the battery set up before i need to run the generator for an hour or so to charge them up. It would stop me getting such a headace if i take it away camping.

ps. Sorry mike getting way off topic.

[mike]

still on topic, since i havnt elaborated what im trying to achieve.

I live on a yacht, a steel one and I'm trying to be completely portable power wise.

I'm mostly 12v power so a 12v alternator does fine for charging the battery banks. I also have a 50amp(dc) smart charger than runs off 230v so can charge that way.

What I really want to run is my 230v inverter arc and tig welder while away from shore power. This draws between 10amps (240v) and 30amps(tig, plasma) hence why looking for a 230v alt.

I have a 1000w pure sign wave inverter to run normal shit but not grunty enough to run the welder. I dont want to stuff the welder with a shitty wave from a genset either.

I also need to run a water maker (which i have to build) and dive compressor so the 240v alt could have supplied power to a 240v motor but i think ill take these as direct drive off the diesel engine i get for it.

are DC motors better than AC motors? or is that vice versa? I probably wont be welding long periods so maybe just a grunty DC alt and grunty pure sign inverter is the trick. or perhaps the ac alt at the correct rev range, governed by electronic governor so the revs never drop produces a clean enough current for the welder with its sensitive electronics. I need some system for powering the welder as I might be relying on it for income while away to help pay for food and fuel.

[safarifern]

Mike, you running a marine diesel in your boat? What's the specs?

[mike]

nope not yet. looking at getting a small 12hp one and converting it. will be running a dry exhaust with a heat exchanger.

this one to be precise thats if the guy comes back to me.

http://www.trademe.co.nz/Browse/Listing ... =348141466

[curly12]

Mike, go onto crew.org.nz and post up there or pm pwederell on that forum. Pete is the guy who knows his stuff, also wheels will be a minefield of info

[safarifern]

If it is 12hp as he said then you should be all good. I recommend you get a 240V alternator and put a small pulley on, then hook up to main drive. Most 240V alternators need between 2000 and 3000 RPM (at alternator) pending the quality to get full power, thus your diesel should idle around half (ish) that, say 1300 to 1600 RPM (ish) .... Then its just 240V cable to a surge protector and plug and you should be all sweet. As you will be just using the engine for 240V power the load will be even and cause no problems.

Now back to you original question .... were to get one??
Marine shops - just start calling around.
Boat builders - see if they have spare units as most refits would put a external gen in and may have an old one to sell.
Boat owners - no doubt your around them ask about they may know of friends / company's that can get you one cheap.
TM - save a search and sit and wait and see if any come up.
Ebay - more common here and our exchange rate is good to buy!

http://www.vw-m.de/index.php?id=285&L=1

The link above shows a RPM to power graph ... the one is high quality so will be different to lower quality one, but you get the idea

[tgaguy1]

I use to use one of these generators

http://southerngenerators.tripod.com/id8.html

In my workshop service vehicle to power my electrical tools. They are not cheap but worth the money.
I don't know if they will satisfy your power demands though.
Just an idea.

Jase.

[Moriarty]

How about one of the ex-army landrovers that were used by Signals, they had a special Alt that cranked out 28V and 90 Amps.

or

http://www.soldsmart.com.au/l3.aspx?goods=DG3673&cam=14