Re: [CAD_CAM_EDM_DRO] 2 transformers wired in parallel to double VA?

On Sunday 05 June 2005 08:17 am, R Rogers wrote:

> Jon,
>
> Sounds easy enough. Thanks for the info.
>
> Ron
>
> Jon Elson <elson@...> wrote:
>
> R Rogers wrote:
> >Thanks for responding Jon, Yes they are made by the same manufacturer.
> > Hopefully the secondaries are color coded and I think they are. Not sure
> > if thats a determining factor on phase to phase. I guess, the way to test
> > would be, If it trips a breaker, it's backwards? Or there must be a
> > better way to determine this?
>
> Yes. Hook the primaries in parallel. Then, only hook TWO of the
> secondary wires together, leave the other pair apart. Measure the voltage
> between those other two wires when you plug it in. If it is just 1 or 2
> volts, you can connect the wires. If it is 110 V, then the phasing is
> backwards. Swap the wires on one of the transformers and repeat the test.
>
> Jon

Let me add that if the phasing is initially incorrect you want to swap _only_
the primary OR the secondary, not both, which would get you right back to
where you just were...