BusBar Amps Calculator
Determine the current capacity of busbars
BusBar Amps Calculator
Compliant with IEC 60439 Standards (for busbar assemblies)
Results:
Cross-sectional Area (mm²): 0.00
Current Density Used (A/mm²): 0.00
Current Carrying Capacity (A): 0.00
How to Use the Calculator
Input Dimensions
- Enter the Width (mm) of the bus bar.
- Enter the Thickness (mm) of the bus bar.
- The calculator will compute the cross-sectional area.
Select Material
- Choose between "Copper" or "Aluminum" for the bus bar material.
- Copper has higher conductivity, allowing for greater current capacity for the same dimensions.
Set Temperature Rise Limit
- Select the maximum allowable temperature rise (e.g., 30°C or 50°C) above ambient.
- A higher temperature rise limit allows for a higher current density and thus more current.
Bus Bar Fundamentals
Bus Bar Ampacity
Ampacity refers to the maximum current a conductor can continuously carry without exceeding its temperature rating. For bus bars, this is crucial to prevent overheating and damage to insulation or adjacent components.
Factors Affecting Ampacity
- Cross-sectional Area: Larger area means lower resistance and higher current capacity.
- Material: Copper has better conductivity than aluminum.
- Temperature Rise: The allowable temperature increase above ambient, influencing the current density.
- Ventilation/Cooling: Natural convection or forced air cooling affects heat dissipation.
- Number of Bars: Multiple bars in parallel can carry more current, but proximity effects must be considered.
Key Formula:
Current (A) = Cross-sectional Area (mm²) × Current Density (A/mm²)
Current density values used in this calculator are approximate and based on common engineering practices for natural air cooling [^2][^3].
Calculation Formulas
Cross-sectional Area (A_cs):
A_cs = Width × Thickness
Current Carrying Capacity (I):
I = A_cs × J
Where:
- A_cs = Cross-sectional Area in square millimeters (mm²)
- J = Current Density in Amps per square millimeter (A/mm²)
Example Calculation
Calculate current capacity for a 50mm x 6mm Copper bus bar with 30°C temperature rise:
Width: 50 mm
Thickness: 6 mm
Material: Copper
Temp Rise: 30°C
1. Calculate Cross-sectional Area:
Area = 50 mm × 6 mm = 300 mm²
2. Determine Current Density (Copper, 30°C):
Current Density (J) = 1.4 A/mm²
3. Calculate Current Carrying Capacity:
Current (I) = 300 mm² × 1.4 A/mm² = 420 A