All Tools
Voltage Drop
Conduit Size
Cable Tray
PF Correction
Generator Sizing
Cable Check
Voltage Drop Calculator
Calculate voltage drop for single-phase and three-phase systems with customizable parameters.
Conduit Size Calculator
Determine the appropriate conduit size based on NEC fill guidelines for your cable setup.
Cable Tray Sizing
Calculate the optimal cable tray size based on cable diameters and fill percentage.
Power Factor Correction
Determine the required capacitor size to improve power factor and reduce energy costs.
Generator Sizing
Calculate the appropriate generator size based on load requirements and starting currents.
Cable Check
Verify cable suitability for voltage drop and short-circuit conditions.
Voltage Drop Calculator (1φ / 3φ)
Typical for multi‑core 50 mm² ~0.08–0.09
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How it's calculated
Resistances at 20 °C: ρCu≈0.017241 Ω·mm²/m, ρAl≈0.028264 Ω·mm²/m.
R (Ω/km) ≈ ρ·1000 / S. For 1φ: ΔV ≈ 2·I·(R·cosφ + X·sinφ)·L/1000. For 3φ: ΔV ≈ √3·I·(R·cosφ + X·sinφ)·L/1000.
%VD = 100·ΔV/VL. Guidance limits: feeders ≤3–5% total depending on standard.
R (Ω/km) ≈ ρ·1000 / S. For 1φ: ΔV ≈ 2·I·(R·cosφ + X·sinφ)·L/1000. For 3φ: ΔV ≈ √3·I·(R·cosφ + X·sinφ)·L/1000.
%VD = 100·ΔV/VL. Guidance limits: feeders ≤3–5% total depending on standard.
Conduit Size — NEC Fill (Rule of Thumb)
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How it's calculated
Cable area Ac = π·(d/2)². Sum areas ΣA. Apply allowable fill: 1 conductor 53%, 2 conductors 31%, ≥3 conductors 40% (NEC Ch.9 Note 9).
Select the smallest trade size whose internal area ≥ ΣA / fill. Internal areas are from typical manufacturer tables (approx.). Always verify with the chosen conduit brand table.
Select the smallest trade size whose internal area ≥ ΣA / fill. Internal areas are from typical manufacturer tables (approx.). Always verify with the chosen conduit brand table.
Cable Tray Size
Enter values and click Calculate to see results...
How it's calculated
Effective occupied width ≈ Σ d (tight) or 1.1·Σ d (loose). Required cross‑section = occupied width × average cable diameter. We then propose a standard width (100, 150, 200, 300, 450, 600 mm) with 50–100 mm side rail height so that tray area × fill% ≥ estimated cable area. Always confirm with thermal derating & manufacturer data.
Power‑Factor Improvement — Capacitor Size
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How it's calculated
φ = arccos(PF). Required reactive power Qc (kVAR) = P·(tanφi − tanφt). Capacitor current Ic ≈ Qc / (√3·V). Use stepped banks to avoid over‑correction at light load. Check harmonic resonance.
Generator Sizing
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How it's calculated
For each load: kVA = kW/PF. Starting kVA approximated as (starting kVA/kW)·kW for motors; duty factor scales kW for simultaneity. We compute total running kW, kVA and compare against the maximum of (running kVA) and (largest motor starting kVA + rest running kVA). Apply diversity and a sizing margin to recommend a genset rating (kVA/kW).
Cable Check — Voltage Drop & Short‑Circuit
Cu PVC≈115; Cu XLPE≈143; Al XLPE≈94 (typical)
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How it's calculated
Short‑circuit thermal check: Smin ≥ Isc·√t / k. If given S ≥ Smin, pass.
Voltage‑drop as in the Voltage Drop module. Provide both ΔV (V) and %VD; compare to a 3–5% guideline. Always validate ampacity/deratings per standard (IEC 60364/NEC) with manufacturer data.
Voltage‑drop as in the Voltage Drop module. Provide both ΔV (V) and %VD; compare to a 3–5% guideline. Always validate ampacity/deratings per standard (IEC 60364/NEC) with manufacturer data.