Need a source for a transformer

[Randybee1]

Anyone have a supply source for a 120 to 240v transformer? I have a 120V, 6.5Kw gen head I want to bump up to 240v and all I can find are people selling prepackaged step up transformers in pretty little boxes with all the bells and whistles... I just want the transformer!

Thanks, Randy B

[mobile_bob]

how many kva are you looking for?

you might keep an eye out on ebay, often times you can find 3-5kva units fairly reasonable, albeit they are heavy and shipping
can be expensive.

also check your area for any industrial surplus yards, they come up there from time to time

bob g

[bschwartz]

What engine are you running?  Even a 6.5Kw gen head will only do about 3.5Kw at best hooked up to a 6/1.
If your loads are lower, consider a 3 KVA transformer like this:
http://cgi.ebay.com/GENERAL-ELECTRIC-9T51B0513-3-kVa-TRANSFORMER-NIB-/220688801730?pt=BI_Circuit_Breakers_Transformers&hash=item336213dfc2#ht_1750wt_1017

[Randybee1]

Thanks guys! This is for my 14hp 2 cyl kubota engine I'm playing with. The 6.5kw genhead puts out 120 volts and I was looking to up it to 240v to hook up to the house. I was hoping there would be some kind of transformer graveyard where I could get a used one and it wouldn't cost me an arm and a leg!

Maybe I'll look into trying to rewire the genhead to put out 240v instead.

thanks... Randy B

[mobile_bob]

that would be the first place i would look, see if the genhead can be reconnected at 240volts

hopefully you will find that the machine is wound with two separate sets of 120 volt windings, instead
of a centertapped 240 winding, apparently if it is the latter and you lose the common you can end up with
240 across a 120 volt load.

i am thinking now that i type this that if you can get 240 our of your head it will be because it is wound with two
separate windings, that is the only way it could be reconnected as a 120 only head economically.

what make/model of head is it, perhaps there is someone on here that will know what you have and what can be
done with it?

bob g

[Randybee1]

Bob, I do not know what make/model it is. It has just enough letters on the tag that it makes you squint for about an hour trying to figure out what it says but you just give up! I did look in the housing a month ago and I "think" I remember seeing 4 wires (not center tapped). I gotta pull it apart this weekend to confirm. Never done a 120 to 240 generator conversion before but it looks pretty strightforward.

I'll look at that label again and post what letters I can, maybe someone will be able to fill in the blanks.

Thanks

Randy B

[bschwartz]

Randy,

Even without the data plate info, these guys can identify nearly anything from pictures.  (hint, hint)

[Henry W]

Randy B,
Is this a brushless genhead? I sounds like you have two seperate 120v windings. Chances are you can hook the two windings in series. What are the four wires coloring? Are there any letters and numbers marked on the wires like U1-U2-U5-U6? If you do it most likely can be wired to 240v. Let us know. If you don't have markings you can check ohms and figure it out that way with the capacitor disconected if it is brushless.


Henry

[Randybee1]

I'll have to pull the gen head apart this weekend and take measurements etc. The gen head itself is probably from the 80's so I'm assuming it has brushes, but then again I haven't looked!
I'll take some pics, measurements etc and get back to you guys latter this weekend

Randy B

Gotta go vote now!. Thank goodness I got a robocall last night telling me the election was postponed until today!.. Technology.. ya gotta love it.. sometimes

[lowspeedlife]

I'll have to pull the gen head apart this weekend and take measurements etc. The gen head itself is probably from the 80's so I'm assuming it has brushes, but then again I haven't looked!
I'll take some pics, measurements etc and get back to you guys latter this weekend

Randy B

Gotta go vote now!. Thank goodness I got a robocall last night telling me the election was postponed until today!.. Technology.. ya gotta love it.. sometimes

OOOHH, robo call huh? some times unscrupulos (sp?) people make up robo calls to make people "think" the election was postponed to keep you from going to the poles.  then when you go the next day it's too late. hope thats not the fact here.


Scott R.

[DanG]

Five or more years ago there was a homemade transformer project somewhere on the internet - a toroidal twenty-some inches across made from steel pallet banding strap and 2 or 4AWG solid copper... I've searched the keywords and can't find any trace of the pages I remember, maybe someone else can snag it. No solid core, all made from very tightly wound loops of banding and a whole slew-load of sleeved insulation and wide insulation tape...

Remember toroids can be stacked - if you find three 1000VA step-ups you have a 3000VA transformer.

On commercial line transformers watch the temperature rate-of-rise - down and dirty cheap transformers cook with heat from losses that cheap utility power may tolerate but really cause your RE or other off-grid power efficiency to suffer.