I recently came across a small xmfr. in looking at the nameplate a question on the diagram not your typical D-Y; curious if this is a D-[open]D?? Any thoughts
I recently came across a small xmfr. in looking at the nameplate a question on the diagram not your typical D-Y; curious if this is a D-[open]D?? Any thoughts
It looks like a T connection, which are commonly used on 3-phase units up to about 15kVA. They only have two sets of fairly standard windings. Effectively they perform like a wye connected device.
There is a variation of the T-configuration, called a Scott-T which can be used to go between 3-phase and 2-phase systems. You can tell the difference by where the X1 conection is made (at the end of the winding or at a tap).
You have 2 coils, tapped appropriately to give 3 phase input and output. You can think of it as using 2 phase internally (the magnetic flux), converting 3 phase current/voltage to 2 phase flux and back to 3 phase voltage/current.