Transformer ratio test magnetic voltage

Transformer Test Typical Transformer no --------------------- Rating 500 KVA, 11/0.415KV apply voltage 415 V primary side and observe the voltage in secondary side- A) Magnetic voltage balance test sr. phases measured voltage 1U-1V 1V-1W 1W-1U 2U-2N 2V-2N 2W-2N 2U2V 2V2W 2W2U 1 R-phase open 178 362 183 3.9 7.9 3.8 11.7 11.8 0.1 2 Y-phase open 70 207 360 7.9 6.1 1.4 14.2 4.6 9.5 3 B-phase open 364 201 81 1.6 6.0 7.9 4.5 13.9 9.5 B) VOLTAGE RATIO TEST SR. APPLIED VOLTAGE tap position 1U-1V 1V-1W 1W-1U 2U-2V 2V-2W 2W2U 2U-2N 2V-2N 2W-2N 1 1 366 368 362 12.91 13.12 13.00 7.39 7.54 7.54 2 2 366 365 357 13.24 13.43 13.30 7.61 7.73 7.72 3 3 365 365 364 13.61 13.60 13.62 7.84 7.85 7.84 4 4 366 368 364 13.96 14.07 14.00 8.03 8.10 8.10 5 5 366 367 363 14.26 14.36 14.34 8.21 8.28 8.28 6 6 366 367 362 14.66 14.79 14.72 8.43 8.50 8.48 C) INSULATION RESISTANCE MEASUREMENT SR. Main winding Meger volt (DC) IR value m-ohm Remarks 1 HV to earth 2500 0 1min 2 LV to earth 500 1 3 HV to LV 500 1.5 1 min D) Oil BDV Test : 9.8 KV conclusion : oil filteration FORMAT Date: ___________ Transformer Test Test report : _______________________________________________________________ Location: _______________________________________________________________ Capacity of Transformer: _______________________________________________________________ Input voltage HT side: _______________________________________________________________ Vector Group: _______________________________________________________________ Tested By: _______________________________________________________________ Work Order No.: _______________________________________________________________ A) MAGNETIC VOLTAGE BALANCE TEST sr. Phases Measured Voltage 1 2 3 4 5 6 7 8 9 1U-1V 1V-1W 1W-1U 2U-2N 2V-2N 2W-2N 2U-2V 2V-2W 2W-2U 1 R-phase open 2 Y-phase open 3 B-phase open Remarks B) VOLTAGE RATIO TEST APPLIED VOLTAGE SR. Tap position 1U-1V 1V-1W 1W-1U 2U-2V 2V-2W 2W-2U 2U-2N 2V-2N 2W-2N 1 1 2 2 3 3 4 4 5 5 Remarks