Cable Size Calculator
Calculate the appropriate cable size based on electrical load and distance. Ensure safe and efficient electrical installations with proper cable sizing.
Understanding Cable Sizing
Proper cable sizing is critical for electrical safety and efficiency. Cable size must meet both current-carrying capacity (ampacity) and voltage drop requirements.
Ampacity Requirements
The cable must be able to safely carry the required current without overheating. This is determined by the cable's ampacity rating.
A 125% safety factor is typically applied to ensure the cable operates within safe limits.
Voltage Drop Considerations
Excessive voltage drop can cause equipment malfunction and energy waste. Standard practice limits voltage drop to 3% for branch circuits.
Voltage drop is calculated using: VD = 2 × I × R × L / 1000, where I is current, R is resistance per 1000 ft, and L is distance.
Conductor Materials
Copper
Copper has lower resistance and higher ampacity but costs more than aluminum.
Aluminum
Aluminum is lighter and less expensive but requires larger sizes for the same current capacity.