ECN Forum Forums Technical Discussion Electrical Theory and Applications Balancing loads

480x208/120Y Transformer

How can the primary be close to being balanced, but the secondarys be way out of whack?

I measured a different trans today and found the readings, primary balanced close, but not secondarys of the wye.


Shouldn't the primary windings be unbalanced just as much as the secondarys?


Anyone got an explanation?


Dnk.....

Since there is no bolted primary to secondary phase connections, the balance on the primary may not match the secondary exactly, but they should be close considering the turns ratio. 2.3x for your transformer

480x208/120 XFMRS is 4:1 not 2.3

The 480 Volt delta windings are wrapped around each 120 Volt wye leg.

4/1.73205 = 2.3 The implied ratio for 208 Volts.

Dnk, you've discovered why high-voltage transmission lines are basically floating delta systems - I've heard an engineer call it "self-balancing".

Larry, can you elaborate on the "floating Delta"?

I assume by your post, the readings I am getting may be normal then?

Dnk.....