Equivalent capacitance of several [n] capacitors in parallel: 
C_{e} = ∑C_{i} 
where i = 1, …, n 
Equivalent capacitance of several [n] capacitors in series: 
C_{e} = 1 / ∑[1/C_{i}] 
where i = 1, …, n 
Capacitive Reactance: 
Xc_{e} = 1*10^{6} / [2πfC_{e}] 
Capacitive Susceptance: 
Bc_{e} = 2πfC_{e }/_{ }1*10^{6} 
Capacitive Admittance: 
Yc_{e }= R_{es} / [R_{es}^{ 2 }+ Xc_{e}^{2}] + jXc_{e} / [R_{es}^{ 2 }+ Xc_{e}^{2}] 
Capacitive Impedance: 
Zc_{e }= R_{es }– jXc_{e} 
Capacitive Reactive Power: 
Qc_{e} = 2*10^{9}πf C_{e}V_{np}^{2} 
Capacitance: 
C_{e} = 1*10^{9}Qc_{e} / [2πfV_{np}^{2}] 
Equivalent inductance of several [n] inductors in parallel: 
L_{e} = 1 / ∑[1/L_{i}] 
where i = 1, …, n 
Equivalent inductance of several [n] inductors in series: 
L_{e} = ∑L_{i} 
where i = 1, …, n 
Inductive Reactance: 
Xl_{e} = 2*10^{3}πfL_{e} 
Inductive Susceptance: 
Bl_{e} = 1 / [2*10^{3}πfL_{e}] 
Inductive Admittance: 
Yl_{e }= R_{es} / [R_{es}^{ 2 }+ Xl_{e}^{2}]  jXl_{e} / [R_{es}^{ 2 }+ Xl_{e}^{2}] 
Inductive Impedance: 
Zl_{e }= R_{es} + jXl_{e} 
Inductive Reactive Power: 
Ql_{e} = V^{2 }/^{ }[2*10^{3}πf L_{e}] 
Equivalent resistance of several [n] resistors in parallel: 
R_{e }= 1 / ∑[1/R_{i}] 
where i = 1, …, n 
Equivalent resistance of several [n] resistors in series: 
R_{e }= ∑R_{i} 
where i = 1, …, n 
RootSumofSquares Current: 
I_{RSS }= [∑I(h)^{2}]^{1/2} 
where h = 1, …, n 
RootSumofSquares Voltage: 
V_{RSS }= [∑V(h)^{2}]^{1/2} 
where h = 1, …, n 
Crest Factor: 
CF = V_{peak} / V_{rms} 

Active Power: 
P_{1P} = IVcosΘ 
single phase systems 
P_{3P} = (3)^{1/2}IVcosΘ 
three phase systems 
Apparent Power: 

S_{1P} = I V 
single phase systems 
S_{3P} = (3)^{1/2 }I V 
three phase systems 
Reactive Power: 
P_{1P} = IVsinΘ 
single phase systems 
P_{3P} = (3)^{1/2 }IVsinΘ 
three phase systems 
Power Triangle Equation: 

S = [P^{2} + Q^{2}]^{1/2} 
Displacement Power Factor: 

dPf = P (1) / S (1) 
dPf = cosΘ 

True Power Factor: 
Pf = ∑P (h) / ∑S (h) 
where h = 1, …, n 
Capacitive Reactive Power Required to Correct a Poor Displacement Power Factor: 
Q_{C} = P(tan^{1}(Θ_{ex})  tan^{1}(Θ_{c})) 

System Capacity at the Corrected Power Factor: 
S_{C} = [1  Pf_{ex} / Pf_{c}]S_{ex} 

Reduction in Losses at the Corrected Power Factor: 
P_{lr} = 1  (Pf_{ex} / Pf_{c})^{2} 

Transformer Base Impedance: 
Z_{base} = V_{np}^{2 }/ S_{np} 
where S_{np} is the OA capacity of the transformer 
Transformer Impedance, %Z Known: 
Z_{xfmr} = 0.01Z_{base}%Z 

Transformer Equivalent Resistance, Efficiency Known: 
R_{xfmr} = (1  Efficiency_{xfmr})Z_{base} 

Transformer Leakage Reactance: 
X_{xfmr} = (Z_{xfmr}^{2 } R_{xfmr}^{2})^{1/2} 

Total Harmonic Current Distortion: 
THD_{I} = (∑I (h))^{ 1/2} / I (1)^{1/2} 
where h = 2, …, n 
Total Demand Distortion: 
TDD = (∑I (h))^{ 1/2} / I_{d} (1)^{1/2} 
where h = 1, …, n 
Total Harmonic Voltage Distortion: 
THD_{V} = (∑V (h))^{ 1/2} / V (1)^{1/2} 
where h = 2, …, n 
Resonant Frequency: 
f_{r} = 1 / [2π(L_{e}C_{e})^{1/2}] 
where C_{e} ≈ 1*10^{9}Qc_{e} / [2πfV_{np}^{2}] 

L_{e} ≈ 1*10^{6}X_{xfmr} / [2πf] 