transformer wiring

[arnettda]

I am a little confused on how to exactly wire this transformer. On 480 primary volts I jumper H2 and H3 together and run one line to H1 and one to H4, How would it be wired for 240 volts primary. This is a used piece of equipment that was 240 volts and we are converting it to 480 volts. What really confuses me as this transformer being 240 volts before is wired like it was hooked up to 480 volts. I am missing how you would wire it for 240 volts as I do not understand the 240 volt diagram as H2 and H3 are hooked to nothing. The diagram on the left that shows just windings and no voltage ratings are H2 and H3 connected where they cross?
Thanks

 

[winnie]

Call your incoming lines L1 and L2.

For 240V in you connect
L1, H1, and H3 together
L2, H2, and H4 together

For 480V you connect
L1, H1 together
H2, H3 together
L2, H4 together

H1...H2 is a 240V coil
H3...H4 is a 240V coil

You put 'em in parallel for 240V in, series for 480V in.

Jon

 

[Hv&Lv]

With the jumper between H3 and H2 the coils are in series.
with the jumper between H1 & H3, and H2 & H4, the coils are in parallel

 

[arnettda]

Thank You, I was totally looking at the LV diagram wrong. I saw the jumper as the coil and not actually the jumper.