ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

I'm back wiring dairy sheds and a 2nd hand alternator turned up here last week.
It has a large diesel engine on the front of it, but when I spyed the name plate on it, it turns out it came from the US.
Single phase voltage is between 120 and 208VAC
Three phase voltage is between 277 and 380VAC.
I'm not sure what to make of this machine, I never even bothered to have a decent gander at the actual machine itself.
All the farmer said was "Pretty Grunty, Eh!!"
Apparently it came out of a hospital, I have no idea which hospital it was.
Will get some pics and move this over to the Pics Submitted Area.

My understanding is, this was bought on the cheap and although the farmer has never heard it run, I think the diesel motor might be had it.

Your thoughts on the voltage though, over here we need a single phase voltage of 230VAC and a 3 phase voltage of at least 400VAC.
Sure this might only be a back-up, but I have a problem with wiring this at all.
Oh BTW, the alternator is 50Hz, just to make it more "fun".

50 Hz isn't from North America. It might have come from the US, but probably wasn't used there. 50 Hz makes the clocks run slow.

Mike:
120/208 single phase/neutral is normal from 120/208 3 phase. 'Y' setup here. The 380 volt, 3 phase is 'odd' to say the least. Our other common voltage is 277/480 'Y'.

And the 50 Hz is not our 'common, as THW said.

Sounds like it was 'made' to run some custom type equipment.

Greg (Gfretwell) is the 'local' maven on the 'odd' voltages here IMHO; he helped me out last week on something I was unfamiliar with.

Good luck, & stay safe!

Mike,

how many output leads are there? Hopefully 12.

Can you verify it is 277/ 480 not 380.

Also verify the frequency. The stated voltages sound like standard 60 Hz values.

You can adjust the hz [50 - 60] at the engine governor. [3000 - 3600 RPM] with the aid of a tacho and a 16oz hammer .
Assuming this isn't a set cobbled together by an amateur, the governor should be able to hold revs within a few % of set speed throughout the power band - and the voltage controller should be capable of maintaining the output with minimal sag within the generator max. output amps. If it's an unmodified vehicle engine nailed to an alternator, it will have an automotive governor designed to run 15% or more sag on demand - it is virtually impossible to drive a diesel-powered vehicle with a generator type governor, [unless you're a kangaroo! ] which would make for some interesting phenomena in use.

I did this back in the eighties, coupling a close-governed fire-pump engine to a huge ancient 36" cylinder-type bowling-green mower. As I lurched up the lawn at ever increasing velocity perched on the roller-seat, the clutch failed to disengage and the governor ignored the throttle. The choice was now between driving into the kitchen [and incurring the wrath of Her Indoors] and a rockery. I chose the latter. The engine finally stalled with me halfway up a larch tree.

If the prime mover is a diesel engine, the engine speed is probably 1/2 to a 1/4 of that. Typical diesel engine speeds for 60 Hz are 900, 1200, and 1800 RPM. Corresponding 50 Hz speeds would be 1500, 1000, and 750 RPM.

If you have access to all 12 output leads (dual voltage) or all six leads (single voltage), you should be able to wire it for single phase dog leg (derated) or three phase output. Tweaking the voltage regulator for a non factory output voltage may require some precision surgery.

Larry, pardon, I assumed pro-rata on the revs, whether that be by pole # numbers or gearing up a 2 pole alternator. The plate says 120-208v. NZ 2010 REGS = 230v±6% 1Ø, 400v±6% 3Ø poco supply as Mike says, so some volts tweaking will be necessary for ideal service. Most stuff would still run at 208/380 and 60hz as a temporary emergency supply, induction motors a bit fast, lights a bit dim[?], Amps a bit higher... breakers replaced with knitting needles! - only joking! A dairy shed may well need 3Ø for the vac-pumps etc..

The biggest hurdle will prob'ly be that oiler lump. If the external condition is reflected inside, no amount of tweaking will help. Only one way to find out, clean filters, clean oil, fuel-up and turn her over....

I just read the destructions [Rule #1 - only to be read once you have wrecked the unit!] on my 6kw 3Ø 415v 2 pole Italian built alternator. The mnfr. recommends setting the Voltage Control 3 or 4% over-voltage to allow for sag when drawing power using a gas-engine drive. The adjuster appears to be a simple setscrew in the pic. [I never touched it from new, the only mod was to ground the centre-tap on delta as recommended on ECN for anti volts-drift.] I use a pair of single-phase duplex-drive 2 pole induction motors [ = 50 hz supply in theory] , pulley-veebelts @ 1:1 to the alternator: this must give me about 4% sag on hz as the motors slip at full chat, but the machinery I run just goes a bit slower, with no probs after 6 years of daily use.

Mike.,

This what you have to do with this primemover { engine } readjust the speed down to 50 HZ so the primemover it have to be 1000 or 1500 T/min { most common depending on which engine } but 1500 T/min is the universal speed for most genney on 50 HZ supply with 4 pole alternator for 6 pole alternator it will be 1000 T/min while 8 pole verison will be at 750 T/min

Once you get the primemover on the correct speed as I listed above then adjust the voltage the 12 lead alterantor will be same as 60 HZ verison beside 120/240 volts 1Ø will not be avabile on that on 50 HZ.

If you can get a photo of that unit one of the guys will indentify it quick ditto with the primemover we can able tell you quick.

Merci,
Marc

Thanks Guys for your ideas.
I intend to get some pics of this unit tomorrow and will post them up tomorrow night.
Oddly enough, this unit must have come from the US, because there is an OSHA sign on it about minimum clearance, referencing the NEC.
It also has a Westinghouse disconnect on the side of it, as far as people over here are concerned, Westinghouse only make refrigerators.

Pretty much, the only things in a dairy shed over here that run on single phase is the flourescent lighting, the power supplies for the pulsator and electronic cup-removers and maybe a few refrigeration controls, the rest of it is all 400V delta connected.

Will keep you posted.

Westinghouse has not built appliances since the 70's or so. But on the other hand they have not built electrical equipment since the mid '90's either.....

Weeell... if you actually manage to get stable 380V phase to phase out of it, most modern 400V gear shouldn't be too unhappy unless you drive it to an absolute maximum - a well-regulated 380V supply is well within the tolerances of a long 400V run (high voltage drop).

This thing has to have some seriously creative winding though if it actually puts out 120/380V, maybe completely separate windings for 120 and 380V?

Well guys,
This is going to be somewhat of an anti-climax, but I've been taken off that particular job and moved on to "the next big thing" (another shed, groan).
I would have loved to have seen how this generator thing panned out, unless I get sent back there to fix something up in future, chances are I'll never set foot in that shed again, dairy construction is like that, but at least you get to see a fair bit of the country-side.

Never say never. When the crud pump fails and they're up to their ankles in it, they'll remember where they left your phone number. In the meantime, you can eat a sandwich.

It is times like that, mate, that I wish I had one of them un-listed numbers.

You'll still get calls, Mike, but that's because the service provider sold your flipping number to a call-center. PITA! You just sit down to a nice plate of bacon, eggs, toast, HP sauce, fried toms and a slab of suet puddin' with lumpy custard and some herbert phones to ask you if you want to buy a heat pump or have your house drenched in woodworm killer. When we bought our broadband-plus-free-phone-calls package, we told no-one our new number and retained our old one to be able to call emergency services in an outage. The cold calls started immediately! In French! Nyyarrggh!

My response to all calls on either phone now is to say "Hell-ohh!" in a very plummy upper-class English accent wot I copied off H.M. The Queen.. . .the call centres usually just ring off!

Alan, eggs and HP sauce, suet pudding and lumpy custard? You don't need an English accent to get rid of those callers. Just tell them what you're eating.

I import my HP [Houses of Parliament] Sauce- it's not to everyone's taste, I know....

Suet pudding is my favorite. Here's a recipe. http://www.deliaonline.com/how-to-cook/baking/how-to-make-suet-pastry.html

Suet is the very hard crumbly beef fat found around the kidney area in a carcase. It was used as a pudding / pie shortening to eke out meagre supplies of meat, so it's akin to Yorkshire Pudding, Pizza or Spaghetti with a sauce. If using fresh suet, you need to remove the fibrous adipose tissue and broken blood vessels by ripping the suet up by hand. Chop the cleaned suet finely - 1/4" chips. My butcher gives it to me for free, as the French don't eat it - and as far as I'm aware, neither does anyone else but us older limeys. You may need to visit a specialty butcher. Lard won't work, and for heaven's sake, don't use bird suet- it's full of chemicals and is likely rancid!!
Fillings: Apple [peel, core, chop, add sugar] is my favorite, steamed for at least 3 hours, when the apple will go pink. My Auntie Gussie, sadly departed these 60 years, used to make fabulous puds when I was a lad. She steamed her "4 pint-ers" all day in the wash-tub boiler! The resultant pudding was as light as a Victoria sponge cake.
Chopped bacon is excellent. Steak is also good, chopped up in chunks, with just a little water and seasoning added before sealing the lid to make some gravy. Steam for 2 1/2 hours to get tender meat, [depends on the type of steak]. Don't let the steamer boil dry. Brits usually add chopped kidney, but that's not to all American's taste. Warning: 6000 calories a slice!
Suet puddings MUST be eaten hot. Once cold they are, frankly, just absolutely horrible - so woff the lot while it's hot! As to lumpy custard- just get your kids to make it- never fails!

To tie this back to the original thread, there's beef in suet pudding and a dairy barn.

What I meant about the sandwich is that when you work in a dairy barn, you don't eat anything you have to touch - which is what would make suet pudding okay. No one who cares about their health would touch it. Thanks for the recipe, though.

If you check the internet, there are ways to get the lumps out of the custard. Yuck!