ECN Forum Forums Technical Discussion Electrical Theory and Applications Transformer Discussion #1

T1c = 3 phase Delta pri. to 3 ph 4 wire Wye secondary - shielded transformer.
Note white wires running into coils for shields.

Hello all!
I thought that everyone would enjoy some pictures I shot recently of some special duty transformers [just the cores/coils - no enclosures].

This one is a 200 KVA 3 phase Delta to 3 phase 4 wire Wye - with shielded windings, along with grounded core.

The small white wires run to the shields.

The large white wires on the fronts of the coils are the % voltage taps

More to follow!! - Please post some comments and/or Qs!!!

Scott SET

ok,
this is normally seen, much focus on that noodle created.(i won't go there if this was not your intent)

the voltage is 1.73 what it would be if the secondary was delta....

Steve,

Ya, this core is similar to the common Delta / Wye stepdown Transformers we all have setup in the field.
The differences in this particular core is the use of "Shielded Windings".
The Shields help to reduce the Capacitive Coupling of EMI / RFI that is something inherent with Isolation Transformers.
The Core is also grounded, which assists with driving those signals to ground levels.

I pointed out the larger white jumper wires on the front center of the coils, to describe where primary %voltage taps are located.
This is because many people are unaware of there location.

As many people are unaware of the primary voltage regulation taps, some are unfamiliar with Transformers all together. Hopefully these pics and the corresponding discussion threads will assist them in gaining some knowledge, or at least some basics, to these devices.


Scott SET