Confused about transformer windings

[electrophile]

I have a toroidal transformer which has two 115V primaries and two secondaries rated at 25VA each (2x18V each capable of delivering 1.389A). I've attached the datasheet here. I'm a bit confused about using this with 230VAC primary voltage. Can I connect the two primaries in series (blue+green connected, 230V mains AC between Brown and Violet) to get 230VAC and the two secondaries in parallel (Red+Yellow and Black+Orange) to get 18V at 2.778A? Color codes are specific to this datasheet.

 

[chuckey]

Thats the way I would do it. If this blows the fuse, disconnect the secondaries, change the fuse, repeat, if it blows the fuse again, swop over the phasing of the primary. Temporarily join one end of of each secondary and measure the voltage across the two free ends, if its not zero volts, swop over the phasing of the secondaries.
Frank

 

[xaccto]

before you hook up power, and your not sure of which wire is the start of each winding, check with ohm meter. You want them in series, so dc resistance must
be at least 2 x the resistance of a single winding. If you make a mistake and connect parallel and power up, serious risk of damage to the winding would occur.
The note about phasing in previous message still applies, but at least you must be sure they are in series.

 

[Borber]

If your transformer is according to datasheet then a proper series connection of primary windings in series is when you connect blue and green wire and connect mains voltage between brown and violet wires. You may allso connect brown and violet wire and connect mains to blue and green.