Re: Transformer wiring hookup 110/220

There's no getting away form the physics of it. If the transformer
can supply a load of 24 V at 10A on 220, you can't get the same
240Watt if you only use half the primary at 110V. Easier said than
done, run it at 110V and start loading the secondary, possibly with
series/parallel 12V car head lamps and read the secondary voltage;
should be 24 volts at 10 amps.

Probably not worth the trouble, I'd send them back and go to another
supplier.

Bernard

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "fozzyber <jerry@o...>"
<jerry@o...> wrote:

> That is what I thought, but when I wire the "reds" together and

wire

> the center black to 110v the transformer hums the lights dim, then
> the strip pops and the transformer gets slightly warm.
> Scary really. But with out both coils going I though I would only

get

> half the amps.
>
> Jerry
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Bernard R
> <bwjarandall@c...>" <bwjarandall@c...> wrote:
> > When wiring a 110/220 transformer, the primarys are paralleled

for

> > 110 and seriesed for 220. If there are two wires on the black
> > terminal, seperate them and parallel the two resulting coils.

I'm

> > suprised that the reset tripped, I would have expected 0v on the
> > output if the phase was wrong.
> >
> > If you look at any dual voltage equipment, the primary fuse is
> > doubled for 110V operation, the corollary is that with only 1

half

> of
> > the primary in circuit, you'll only get half the secondary amps.
> >
> > Bernard
> >
> > --- In CAD_CAM_EDM_DRO@yahoogroups.com, "fozzyber <jerry@o...>"
> > <jerry@o...> wrote:
> > > I received my transformers today!!!
> > > I went to wire them up and had to stop to think about how to

wire

> > > them.
> > > The transformers are (http://www.mpja.com/product.asp?
> > product=7846+TR)
> > > I hook the blues up for 24V, no problem
> > > The primary is what is confussing me.
> > > There are 2 red wires and one black.
> > > the label on top shows as follows
> > > RED 110V| |BLUE 12V
> > > | |
> > > Black | |Yellow
> > > | |
> > > RED 220V| |BLUE 12v
> > >
> > > I would assume if you were using a 220V you would just wire the
> > reds,
> > > and leave the center black disconnected.
> > > but what about 110V? I Hooke one red and the black.
> > > and bingo 24V across the blues.
> > > I started to think about this and though but I don't have the
> other
> > > half of the primary hooked up.
> > > So I wired the other red to the first red.
> > > The transformer hummed for a second, then tripped the reset on

my

> > > power strip.
> > > How do I wire for both primarys to power up?
> > >
> > >
> > > Jerry