DC Power Cable Size Calc 1.1

The DC Power Cable Size Calculator is a valuable tool designed to estimate the appropriate wire gauge or size based on critical parameters such as wire length, voltage, and current (in amps). This functionality is especially useful in electrical applications where accurate specifications are essential.

Features:

• Instant calculation of wire sizes
• Results can be easily copied to other applications
• Inclusion of formulas for reference
• Support for various units for each input parameter

Cable sizing plays a crucial role in low voltage systems, particularly for battery cables, wind turbines, solar panels, and load cables. One of the most common issues encountered in low voltage systems (12V, 24V, or 48V) is voltage drop resulting from improperly sized cables. Insufficiently sized cables can lead to overheating, posing a fire hazard, while oversized cables may result in inefficient energy use.

Calculation Formula:

VDI = (Amps x Distance) / (% Volt Drop x Voltage)

• VDI: Voltage Drop Index, a reference number based on the resistance of the wire
• Distance: One-way wiring distance in feet
• % Volt Drop: Acceptable voltage drop percentage

The cable size by cross-sectional area (Copper) can be determined using the formula:

mm² = VDI x 1.1

The acceptable voltage drop value will vary depending on the specific application. A standard threshold of 2% is recommended to ensure that electrical sources function at their full potential. A voltage drop of 5% or greater is often acceptable in automotive contexts.

Safety Guidelines:

• Cable sizes should serve only as guidelines; all figures must be verified against manufacturer data sheets.
• Cables should always be fused or current protected to their maximum rating or lower.