Where (Z_t) = transformer impedance, (Z_c) = line impedance. Excel uses iterative approximation. The Excel file Instalaciones_Electricas.xls contains seven interconnected sheets:
[ \Delta V = \frac2 \cdot L \cdot I \cdot (R \cos\phi + X \sin\phi)V_n ] hoja de calculo excel para instalaciones electricas xls
Conditional formatting highlights when ΔV > 3%. Where (Z_t) = transformer impedance, (Z_c) = line impedance
The complete .xls file with all sheets, dropdowns, and conditional formatting can be generated upon request. End of paper The complete
Cable impedance: =Z_cable_per_km * L / 1000 Total short‑circuit current: =V_n / (SQRT(3) * (Z_transformer + Z_cable)) Circuit breaker rating (I_n) must satisfy: (I_b \le I_n \le I_z) (I_z = cable ampacity) And (I_sc \ge I_instantaneous) for magnetic trip.
=INDEX(ConductorDB[Section], MATCH(TRUE, ConductorDB[Ampacity] >= F2, 0)) Then check VD; if too high, increase section manually or with solver. 4.3 ShortCircuit Sheet Transformer data: (S_t) = 250 kVA, (V_sc)% = 4.5%. Transformer impedance: =(Vsc%/100)*(V_n^2 / S_t) in ohms.