Answer / prasad@clp

HV side Delta,LV side Star
1) Connect HVside with 3 phase supply,
2) Short with a cable HV R phase & LV r-phase,
3) LV left open circuited
4) Now Switch on the 3-phase supply
5) Now Measure the following Voltage's
VRY,VYB,VRB
VRN,VYN,VBN
Vry,Vyb,Vrb
VRr,VRy,VRb
VYr,VYy,VYb
VBr,VBy,VBb
6)CHECK the following condition(These are derived from
Phasor diagram)
i) VBb<VBy
ii)VYb=VYy
iii)VRY=VRn+VYn
iv)VYb<VYy
If these all conditions are satisfied then U'r transformer
is OK

ALL THE BEST------Prasad

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