Required Cross-section
TOOLS
Bus Bar & Fusing Calculator
Compute cross-section, resistance, thermal rise, and fuse sizing for HV bus bars.
How this works
R = rho * L / A, P_loss = I^2 * R
Methodology
DC resistance: R = ρ × L / A. Self-heating: ΔT = P_loss × R_th. Fuse sizing follows IEC 60269 derating curves for continuous and pulsed DC loads.
Calculator Inputs
Material & Finish
Geometry
mm
Electrical Load
A
A
Thermal Boundary
C
C
Current Density
2.59 A/mm2
Resistance
0.059 mOhm
Power Loss
7.3 W
Temp Rise
72.7 C
Fuse Rating
500 A
Thermal rise is high, redesign required
Current Density vs Width (at 30mm width)
Safe (<3 A/mm²) Warning (3-5 A/mm²) Danger (>5 A/mm²)
Dimension Options (copper)
| Width (mm) | Thickness (mm) |
|---|---|
| 20 | 6.77 |
| 25 | 5.41 |
| 30 | 4.51 |
| 40 | 3.38 |
Cu vs Al Comparison
| Material | Area (mm2) | R (mOhm) | Loss (W) | Delta T (C) |
|---|---|---|---|---|
| copper | 135.33 | 0.059 | 7.3 | 72.7 |
| aluminum | 221.45 | 0.061 | 7.5 | 75.2 |