Does anyboydy knows how to ratio a delta/zig-zag transformer?

[Danyboymx]

I have 3 phase 480/208-120 delta/zig-zag transformer that gave me bad ratio when tested with a Vanguard TTR test set. Any ideas how to ratio this transformer using a voltage source on the primary and a voltmeter on the secondary?

 

[Millbo]

I ran across this some time ago. I was also using the Vanguard TTR test set.

If memory serves I tested it as a Delta-Delta

 

[rhatcher]

Try disconnecting the jumpers and test the individual coils from primary to secondary.

This is necassary because each leg of the secondary consists of groups that have induced voltage from two separate primary legs.