Transformer primaries out of phase?

[delverboy]

Old brain in need of help.
I just hooked up a new Antek AS2225 and it seems the primaries are out of phase because there's a noticeable hum and it starts to get warm. The secondary voltage seems correct but there's no load connected.
I wired the primaries in parallel, with the two red leads together and the two black leads together. I plan to reverse the leads, but just wondering if I read the diagram wrong or did the manufacturer get the colors wrong?

 

[egellings]

There are no phasing dots on the transformer's schematic diagram, so it's hard to tell. Seems to me, absent the dots, tying the blacks together and the reds together for 115Vac operation should be the way to go. I'd question the mfr, if that's possible. You might also have a defective, unit, too. An experiment you could try is to energize just one primary winding and read the output voltages. Do the same with just the other primary winding powered. Results should be close to the same using either primary winding. If not, then the transformers has a problem.

 

[kevinkr]

Don't reverse the leads red-red, black-black is correct, this will essentially be a dead short across the primary windings since the magnet fields will oppose each other and cancel out basically only the DCR of the winding limits the current. The buzzing and heating may be due to residual DC on your AC line. A DC blocker may be in order.

(I have used a lot of Antek transformers in my own projects)

 

[egellings]

A DBT setup should be used. Two primary windings bucking each other will quickly blow th fuse or smoke the transformer.

 

[daqvin_carter]

I would say dim bulb test first. If you do not have a hard short I would have to ask if the noise is from exceeding the primary voltage.
Another way to test would be connect the black primary wires and leave off one of the red primary wires. With power applied do you still get noise? Also is there any real voltage difference between the red wires??

 

[ItsAllInMyHead]

Make sure you don't have a shorted turn.

Confirming what was mentioned previously; leave it as is with red to red and black to black.

 

[MarcelvdG]

Another way to test would be connect the black primary wires and leave off one of the red primary wires. With power applied do you still get noise? Also is there any real voltage difference between the red wires??

That's a very good proposal. You should get about twice the mains voltage between the red wires if the polarity is wrong and almost zero times the mains voltage when it is correct.