50 hz gen to 60 hz

[binnie]

Thank You Andy,
Looks like just the type of Transformer I will need. It is all coming together nicely. Don't know what I would do without this forum: It is a god send. I have wiring manuals on the way for the SOM, thanks to Rick Janes, a method of getting usable output from the machine, thanks to you, and an overseas crater for my machine, tks to Mike Montief, and a reasonable shipper thanks to T19. Great guys, all of you. Just hope I can return the favours. I am indebted. THANK YOU, binnie (yes T19, I'm screeming) !

[Doug]

Better to look up on the net and learn how a transformer works then squint at that and judge your needs lol.

I don't know much about outback products, I'm think they are good.

I'd look for a used single phase lighting transformer double the size you need and just use the X1 threw X4 in what ever auto config fills your needs....

Doug

[buickanddeere]

  Used 5,7.5 & 10KW single phase transformers with 600V  or 480V input and 120/240 input are a dime a dozen during building renovations, tear downs etc.
  Just leave the 600V side open and connect your single phase 240 machine across the transformer's 240 terminals.You will have to be certain the 240 generator winding sare floating and not tied on one end to chassis or ground.
   The center of the transformer will become the neutral. It will have to be refernced to ground if used with a 3 pole transfer switch or used as a stand alone generator. The neutral needs to be floated if used with a two pole transfer switch and the generator not used as a stand alone.

[Doug]

I like the Idea of the 600 still being there on H1 and H2 incase I want to move some power significantly further down the line to say a remote building.

480....
I think I've only seen that used twice up here, I understand its more Common in the south....

Doug

[Dursley Dave]

Hi all! Just reading through this thread and I have the opposite problem!
I have a Petter PH2W hooked to a stamford-Newage 7.5KVA single phase head, rated at 60HZ
Because Im in England I need 50HZ. So, I throttled back the revs from 1800 to 1500 and the voltage dropped from 230 to 197. I took the cover off the head and saw a kind of wound bobbin with a sliding tapping on it, (Obviously to regulate the field current) to get the voltage up, I ended up taking the whole of this resistor out of the circuit. but the voltage is still down, at 210.
Is there a way that I can get the volts up to 240? there is also two rectifiers in the end of the head with wires a plenty coming out of em!

[mobile_bob]

its impossible, can't be done,,

you have two choices

a. move to the states

b. stay there and send it to me



bob g

[ronmar]

Hi all! Just reading through this thread and I have the opposite problem!
I have a Petter PH2W hooked to a stamford-Newage 7.5KVA single phase head, rated at 60HZ
Because Im in England I need 50HZ. So, I throttled back the revs from 1800 to 1500 and the voltage dropped from 230 to 197. I took the cover off the head and saw a kind of wound bobbin with a sliding tapping on it, (Obviously to regulate the field current) to get the voltage up, I ended up taking the whole of this resistor out of the circuit. but the voltage is still down, at 210.
Is there a way that I can get the volts up to 240? there is also two rectifiers in the end of the head with wires a plenty coming out of em!

Probably not without re-winding something or building an external regulator to feed the field.  I am not familliar with the generator you are talking about, but it sounds as if it is harmonically excited.  The harmonic windings are wrapped in such a way that at rated RPM they deliver enough average power when rectified to properly feed the field and deliver the desired output voltage.  It sounds like you also had a variable resistor to fine tune the ammount of current fed to the field and set the output voltage.  By dropping to 50 HZ, you have lowered the average output from the harmonic windings(fewer passes thru the magnetic field per second).  The only way to get that back is to increase the size of the windings to catch and convert more of the magnetic field into current to be rectified and feed the field winding.  

[solar]

you also might be able to increase the reduced (rectified) feed to the brushes at 1500 rpm by adding a large (electrolytic) capacitor across the brushes to better filter the dc from the rectifier.  That added capacitance should boost the excitation a bit and it just might be enough to get your field current back into range.

a cheap (maybe) fix, and no assurance of good (sufficient output voltage) operation under load, but you might give it a go...

Solar 

[Doug]

Sliding the that tap over on that will probably adjust your field current up or down.
Many sets have this sort of thing and no it won't cause your batteries to melt because the induced voltage in your DC armature windings will also drop withthe decrease in speed and your only increasing the excitation to compensate.

That much said, I haven't seen what you have and you may have something different there, but more likely you have a voltage adjustment there.  Removing things like that are probaly not a good idea.

If you can't manage 240 v at 50 you might be abvle to get away with 60 hz. Most 50 hz motors and equipment runs just fine on 60 ( and motors develop about 15% more power ). Obviously record players and wall clocks will not, computers and electronics with switching power suplies will probablybe ok but you need to check the manuals and in some cases the manufactures for more info.

Doug

[Dursley Dave]

Thats the trouble, the washing machine spin cycle may cause probs at 60HZ, electric clocks would would ebb my life away quicker, microwave oven wont work at anything but exactly 50HZ. I dont know if flourecent lights are sensitive to HZ?

The other thing is, I dont know what the head would now be rated at in KVA now its had a drop in rpm.

I bought this set from a mate, late @ night by torch light! I didnt read enough of the plate on the gen head........just saw 7.5 KVA and thought "That will do nicely!"

The engine is rated @12hp @ 1500 or 16hp @ 1800, so it wont be short of power with this setup.
The Stamford head is a substantial bit of kit, massively built and with the sliprings double brushed..........maybe I could come to an arrangement with it and fine tune the rpm a bit just to creep the volts up...it now needs 54HZ to give me 240v, I just tried it.

Would I do more harm if I ran my appliances under voltage against over voltage? sorry for all the questions, but as an electrician, I make a good painter!

[adhall]

If you decide that you simply can't get the generator output up to 240 V, you could use a boost transformer to get it there. I don't know if commercially made units are available for 50 Hz -- I've only worked with 60 Hz personally. You might contact a local electrical supply house.

You can do the same thing using an ordinary transformer that has a low voltage, high current secondary. If you aren't too familiar with electrical things, you probably would want some hands on help doing this, though.

Best regards,
Andy Hall

[Doug]

Yes Dave under voltage is worse than over for most things with motors, but incandecent lamps and ballasts will run a hotter at higher voltages.

54 Hz might be a good try it.

60 Hz will spin your washer 20% faster, I dunno what might happen. We have a guy here who worke for GE doing apliance repairs maybe he can provide some input.....

Sometime ago I did work at the Ministry of Mines labs here. PSecificaly we had some mills and and crusher made in NZ that were designed for 50 hz. Mechanicaly this made no difference but he extra speed caused samples to heat up and burn the paper bags the samples dropped into as well as melt plastic parts on the machines. When you increase or decrease the speed on machines often things happen you may not count on.

Generaly if you take a 50 Hz machine and run it at 60 you increase the speed and add about 15% more hp in the process with no hitches. When you run 60 hz at 50 you often have to derate by about the same amount depending on the aplication.

Doug

[sid]

Doug/// not much help on the 50 hz///only saw a few washers that had been shipped back by military familys and had been changed to 50hz../use to be a kit to convert/ but have not seen one in 20 years /// a call to the manufactor would let you know if a one was available for the product/sid

[Doug]

The " Kit "  might have some larger value start/run capacitors, Centrifugals usualy cut out at 75 % syncronous speed so they are probably ok for 50 hz.

Just guesses on my part, 3 phase stuff like I usualy deal with generaly get rewound, the exception being 380 50Hz going to the USA where 460 is common that usualy works without modification.

Friend of mine in the army brought back a Klischp amp from Germany, that ran fine on 240 60hz. His Pevey tube amp worked on 50hz with a transformer.

Doug

[listeroidsusa1]

It is fairly easy to get the voltage on the field back up. All it takes is an small autotransformer or a variac. Most variacs will output around 120% of their input voltage. Take the output and run it though a diode bridge to get your mains voltage up to 240. The variac knob gives you a way to fine tune your generator.