B Formulas Flashcards
1
Q
% voltage regulation
A
Vs no load - Vs full load ÷ Vs full load
2
Q
Full load copper loss
A
I squared x R (winding resistance)
Do this for both the prime and secondary voltages and add them together
I = VA ÷ V
3
Q
Calculate % of load copper loss
A
Eg. 50% is 0.5 squared x full load (w)
4
Q
% eff - % efficiency of a transformer
A
Power output devide by power input x 100
Power output = VA x Pf
Power input = power output plus all losses
5
Q
%IZ - percent Impedance
A
Impedance voltage devided prime rated voltage x 100
Done with a short cct test at the time it was manufactured
6
Q
Maximum available short cct current
A
Full load secondary current ÷ %IZ
7
Q
Isc - Short cct current formula
A
Isc = Isc rated devided %IZ x 100
8
Q
Find secondary no load.
What’s the formula?
A
Vs no load = (1 + %VR) x V full load
