hi....I am from india..i have completed my engineering in
electrical and electronics field with 58.4% and my IELTS
score is 5.5 bands....Recently i received my I-20 in
computer and information science from Troy university in
Alabama.On 18th i have a visa interview can u please tell me
what type of questions i have to answer ??????
Sir we have 12.5 MVA(110/11KV) transformer (Y-Y)
connected,which tripped showing earth fault,when we charged
transformer it stood OK ,but on connecting 11 KV feeders it
tripped showing earth fault.our service engineers found that
the B phase and R phase phase connecting to neutral broken
from HV OLTC(on load tap changer),and R phase and Neutral is
ok.Dissolved gas analysis shows that accetline content is
high,tan delta value is 12.My dout is it is an internal
fault of transformer,why REF or diffrential relay is not
Draw the flow of F.O. diagram from service tank to Main Engine?
I have a small system with two motors that are running on
380 vac, 60 hz. These motors are expensive and I usally get
them from Brazil. I am adding another motor to the system,
but I want to purchase a 480 vac, 60 hz motor to use. It
will be on a VFD that is rated fro 380 thru 480. Is this
posible and will I have to use a larger motor and derate it?