Hi.
Are the indetical trafo's.
Standart 4 rules of trafo paralleling.
1. Same vector group ( O.K. possible with some changes on primary, connect Y/D5 with Y/D5 or Y/D11 with Y/D1, see FAQ, Stevenal's)
2. Similar ratio as possible, voltage. U1=U2 ( that means same tap position)
3. Same impedance voltage Uk , with difference no more +/- 10%
4. rated power outpot ratio smaller than 3:1
Regards.
Slava
I agree with Slava's points, but it's not clear what stage you are at from your original post. If you are at the point where the transformers are already installed and connected, then you need to energise them both, upto the open device that will make the parallel. Measure the ph-n and ph-ph voltages derived from each transformer to check they are the same, or very close. Then measure the voltages between all three phases across the open device to check that the two sources are in phase. R1-R2, Y1-Y2, B1-B2 should be roughly zero, R1-Y2, Y1-B2, B1-R2 should be the normal system phase to phase voltage.
Regards
Marmite
Fuse the smaller transformer with the smallest fuses that will hold the inrush. If you are able to close the paralleling device succsesfully, then replace the fuses with the proper sizes.
Bill
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"Why not the best?"
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