Electrical Engineering Calculators
Calculate cable ampacity (IEC 60364-5-52), voltage drop, busbar capacity (DIN 43671), power factor correction (kVAr), star-delta motor current, transformer short-circuit current and IP/IK protection ratings.
Calculators and reference formulas
| Calculator | Formula / Standard | Scope | Related product categories |
|---|---|---|---|
| Current and Breaker Size Calculator from Active Power | Three-phase: I = P / (√3 × U × cos φ × η) | Calculate the approximate line current of motors, heaters and other electrical loads from their active power. | Miniature Circuit Breakers, Molded Case Circuit Breakers (MCCB), Low-Voltage Cables |
| Cable Current-Carrying Capacity Calculator | Corrected capacity: Iz = Iz₀ × k₁ × k₂ | Cross-section alone is not enough. The same cross-section carries a different current depending on insulation, installation method, ambient temperature and the number of circuits running side by side. | Low-Voltage Cables, N2XH Halogen-Free Cables, NA2XH Aluminum Cables |
| Busbar Current-Carrying Capacity Calculator | Continuous current: I = I₀ × (Δθ / 30)^0.61 × √(R₆₅ / R) | For busbar selection in panels and distribution systems, correct the DIN 43671 (copper) and DIN 43670 (aluminum) continuous current values for ambient and busbar temperature. | Busbars and Distribution Blocks, Panels and Equipment |
| Voltage Drop Calculator | Three-phase: ΔU = √3 × I × L × (R cos φ + X sin φ) | Find the voltage at the end of the line and the percentage voltage loss, taking into account how conductor resistance changes with temperature and the reactance of AC lines. | Low-Voltage Cables, NYY Underground Cables |
| AWG to mm² Converter | AWG: d = 0.127 × 92^((36 − AWG) / 39) · kcmil: A = MCM × 0.5067 | Convert American Wire Gauge and kcmil/MCM sizes to conductor diameter and actual geometric cross-section. For metric cable orders, compare the IEC nominal size that does not drop to a smaller cross-section. | Low-Voltage Cables, Signal and Control Cables |
| Power Factor Correction (kVAr) Calculator | Qc = P × (tan φ₁ − tan φ₂) · Three-phase current: Ic = Qc / (√3 × U) | Calculate the total capacitor bank power (kVAr), the kVAr/kW factor and the reduction in line current needed to raise the existing power factor to the target cos φ. | Power Capacitors, PFC Contactors, Reactive Power Control Relays |
| Star-Delta and DOL Motor Current Calculator | In = P / (√3 × U × cos φ × η) · IΔ = In / √3 · IY = In / 3 | Compare line current, winding branch current (IΔ = In / √3) and star contactor current (IY = In / 3) for direct-on-line (DOL) and star-delta motor starters. | Power Contactors, Thermal Overload Relays, Motor Protection Circuit Breakers |
| Transformer Short-Circuit Current Calculator | In = S / (√3 × U) · Ik = In / (uk / 100) | Find the nominal secondary current at a distribution transformer's terminals and the prospective three-phase short-circuit current (kA) assuming an infinite upstream busbar. | Molded Case Circuit Breakers (MCCB), Air Circuit Breakers (ACB), Miniature Circuit Breakers |
| IP and IK Protection Rating Calculator | IEC 60529: IP [Solid: 0–6][Water: 0–9] · IEC 62262: IK00–IK10 (Joules) | Check the meaning of the first and second IP numerals and the corresponding IK impact energy (joules) from the standard tables for panels, boxes and luminaires. | Panels and Equipment, Junction Box Enclosures |
| Cable Type Code and Letter Symbols Decoder | VDE: [N/NA][Y/2X][C][Y/H] [-J/-O] · HD 361: [H05/H07][V/R/N]-[U/R/K/F] | Look up the conductor, core insulation, screen, outer sheath and rated voltage meaning of VDE and harmonized HD 361 cable type designations. | Low-Voltage Cables, Signal and Control Cables, Fire-Resistant Cables |
| Cable Copper and Aluminum Weight Calculator | m = n × S × ρ · Copper: ρ = 8.89 kg/(km·mm²) · Aluminum: ρ = 2.70 kg/(km·mm²) | Calculate the theoretical bare copper or aluminum conductor weight (kg and kg/km) of a cable from core count, nominal cross-section and length. | Low-Voltage Cables, Sheet Metal Cable Trunking |
| Cable Trunking and Conduit Fill Calculator | A₁ = π × d² / 4 · A_total = N × A₁ · A_pathway = A_total / k_fill | Find the total external cross-sectional area of your cables from outer diameter and count, and see the required internal area and standard trunking size. | Cable Trunking, Panel Wiring Ducts |
| Current Transformer Ratio and VA Burden Calculator | R_loop = 2 × L × 0.0175 / S · P_wire = I_sn² × R_loop · S_total = S_meter + P_wire | Select the next standard current transformer ratio from line current and calculate total secondary VA burden including copper lead losses. | Current Transformers, Power Network Analyzers |
| Motor Energy Consumption and Efficiency Calculator | P_in = (P_shaft × k_load) / η · ΔE = (P_in1 − P_in2) × t (kWh/yr) | Calculate annual electric motor energy consumption (kWh/year) and the kWh savings achieved by upgrading from IE2 to IE3 or IE4 efficiency classes. | Motor Protection Circuit Breakers, Motor Starters |