Multiple Transformer Inrush
Multiple Transformer Inrush
(OP)
HI - We have a customer with 10, 1 MVA transformers connected to our utility system at 13.8 kV three phase. Our current practice for fuse sizing is to assume that the inrush current would be the same as for 1 - 10 MVA transformer. Does anyone know if the total inrush for multiple transformers can be reduced due to the fact that there are multiple connections with smaller transformers?? Our protection people state that the fuse will blow when the feeder auto recloses, however they have had multiple relcoses over the years with no such issues.....
Any information or reference would be appreciated.
Thank you,
Veman.
Any information or reference would be appreciated.
Thank you,
Veman.






RE: Multiple Transformer Inrush
You'll have to use actual xmfr's %Z values to figure out the actual impact here. Don't forget to allow for the impednaces of the primary cables/wires as well.
RE: Multiple Transformer Inrush
Do you have any references relating inrush to transformer impedance? Usually it is shown as a multiple of full load current.
RE: Multiple Transformer Inrush
veman
RE: Multiple Transformer Inrush
RE: Multiple Transformer Inrush
The point on wave form that switching happens, Remanence flux and transformer design can affect all this.
RE: Multiple Transformer Inrush
Alan
Democracy is two wolves and a sheep deciding what to have for dinner. Liberty is a well armed sheep!
Ben Franklin
RE: Multiple Transformer Inrush
RE: Multiple Transformer Inrush
Alan
Democracy is two wolves and a sheep deciding what to have for dinner. Liberty is a well armed sheep!
Ben Franklin
RE: Multiple Transformer Inrush
RE: Multiple Transformer Inrush
Thank you again....
Veman.