transformer symbols
transformer symbols
(OP)
Hi everyone
My knowledge of electrical stuff is not the best.
Can someone explain the meaning of the following symbols used on three phase transformers, and how do you determine it:
: Z%
: Z0%
: X/R ratio
I've seen on the nameplates of some transformers just the MVA, the voltages and currents(pri. and sec.), the impedance (X%), type of cooling and the vector symbols.
Thanks
My knowledge of electrical stuff is not the best.
Can someone explain the meaning of the following symbols used on three phase transformers, and how do you determine it:
: Z%
: Z0%
: X/R ratio
I've seen on the nameplates of some transformers just the MVA, the voltages and currents(pri. and sec.), the impedance (X%), type of cooling and the vector symbols.
Thanks






RE: transformer symbols
z0% = transformer zero sequence impedance
x/r ratio = the ratio of reactive and resistive components of the transformer
Mike
RE: transformer symbols
1.So z% is the same thing as x% ?
2.How do you calculate z0% and the X/R Ratio? - I haven't see it on any transformer nameplate.
RE: transformer symbols
Z0% is equal to Z% for two-winding transformers with solidly grounded neutrals. Except as seen from the delta side of a delta-wye transformer, Z0% is infinite. For three-winding transformers, you need tests of the individual winding impedances.
The X/R ratio is X% divided by R%. If you have Z% and calculate R% as above, you can calculate X% by solving the above equation for X.