Copper Busbar Current Rating Calculator
How It Works & Technical Derating
Busbar ampacity is proportional to cross-sectional area and thermal dissipation surface. Multiple parallel bars suffer from skin effect and reduced airflow between conductors.
Equations & Multipliers:
1. Total Cross-Sectional Area A (mm²):
A = Width (mm) × Thickness (mm) × No. of Bars
2. Total Current Capacity (A):
Current = (Single Bar Area × Base Density) × Derating Factor (k)
Parallel Bar Derating Factors (k):
- 1 Bar = 1.0 (Full Efficiency)
- 2 Parallel Bars = ~1.7 (15% loss due to proximity)
- 3 Parallel Bars = ~2.25 (25% loss due to heat trapped)
- 4 Parallel Bars = ~2.70 (32% loss)