Medium Voltage 3 phase Transformer Terminals.
Medium Voltage 3 phase Transformer Terminals.
(OP)
We have 3 phase 26.4kV Delta - 490 volt Delta and 490 volt Wye, 3 winding transformer which feed 12 pulse rectifier on 490 volt side, generating about 3 MW for Traction service. This oil filled transformer has nameplate but no markings at 26.4kV bushings for H1, H2 and H3. Similarly on secondary R1, R3 and R5 are Delta and R2, R4 and R6 are Wye bushings with no markings. My main concern is to find H1 bushing on primary.
1. Assuming I stand on 490 Volt bushings facing 26.4 kV bushings, which side is H1 bushing....on right hand side or left ?
Thanks in advance.
PD
1. Assuming I stand on 490 Volt bushings facing 26.4 kV bushings, which side is H1 bushing....on right hand side or left ?
Thanks in advance.
PD
RE: Medium Voltage 3 phase Transformer Terminals.
RE: Medium Voltage 3 phase Transformer Terminals.
RE: Medium Voltage 3 phase Transformer Terminals.
Thank you.
RE: Medium Voltage 3 phase Transformer Terminals.
RE: Medium Voltage 3 phase Transformer Terminals.
RE: Medium Voltage 3 phase Transformer Terminals.
It seems that Fig 3 -Bushing arrangement, matches with what PRC wrote (Left side is H1 bushing, if you are on secondary bushings looking at high side bushings.) It seems that ANSI 57.12.10 may be defining it in a different way, but Fig 3 is very clear for H1 position. You have a point that R1....R6 are not per Std.
This transformer is Rectifier Transformer, and now I am not sure how R1...R6 orientation is, wrt high side. If you see the nameplate dwg, H1 and R1 are shown diagonally opposite. But nameplate may not represent physical layout.
If anyone out there who has dealt with rectifier Transformer, will be better able to assist with both HT and LT bushings orientation.
Thermionic1, This transformer has Off-load tap changer which can be operated by rotating a big knob located in the center of the top of the transformer. Thanks.
RE: Medium Voltage 3 phase Transformer Terminals.
RE: Medium Voltage 3 phase Transformer Terminals.
RE: Medium Voltage 3 phase Transformer Terminals.
PRC Sir may throw more light on this. Thanks.
RE: Medium Voltage 3 phase Transformer Terminals.
As far as Off-Load tap changer is concerned, one has to physically climb on top of this transformer and rotate the knob which is located in the exact center of the top plate.
I see that 490 volt secondary bushings, R1...R6 may not match a standard, but probably will have some accepted industrial practice. I will try to contact one transformer manufacturer, if he can shed some light on this old GE unit. I will share if I get any more info.
Thanks.
RE: Medium Voltage 3 phase Transformer Terminals.
From IEEE 1653.1-2016 IEEE Standard for Traction Power Rectifier Transformers for Substation Applications up to 1500 V DC Nominal Output
From IEEE 1653.2-2020 IEEE Standard for Uncontrolled Traction Power Rectifiers for Substation Applications up to 1500 V DC Nominal Output