How To Choose The Right Wire Size
It is important to carefully select the correct wire sizes for any electrical project. Incorrectly selected wires can overheat and cause fires. There are two considerations for wire size.
- The maximum current a given wire can flow without heating enough to melt off the insulation material.
- The Voltage Drop caused by the resistance of the wiring. Resistance increases with reduced with wire diameter and increased wire length.
Given these considerations we need to gather some information to make an informed choice.
Firstly we need to know the current that will flow through the wire. If you don't know this see this guide to learn how to determine the current in your circuit. Alternatively the equipment documentation usually contains this value.
Secondly we need to determine the length of the circuit in Meters. This length is the round trip length Eg, From the battery through the appliance and then back to the battery. The longer this length the thicker your wire will need to be.
Thirdly we need to consider the operating environment of the wiring. How many wires are bundled together and what will the ambient temperature be around this bundle. This is important because the wires installed in an engine bay are in a much hotter environment. This can melt wire with less current flowing.
Enter the determined values in the wire size calculator below to get your result.
All electrical systems present a risk of fire and other hazards. Fuse Factory makes no representation or warranty that this calculator will be suitable to address your particular situation or requirements.
Fuse Factory has developed this calculator for use only by individuals having the appropriate working knowledge and understanding of electrical systems. The Calculator is based on Industry standards including E-11 “AC and DC Electrical Systems on Boats,”. It it is not a substitute for calculations based directly on these or other industry standards that may apply. These calculators are prototypes, and may contain errors of entry or calculation.
These calculators can not account for all possible circumstances, factors or variables pertinent to the selection of an appropriate wire and circuit protecting fuse. These variables could include adding additional loads to circuits, Inadequate or defective insulation, Software malfunctions of a browser or server computer, data import errors, environmental heat sources, Heated terminations such as fixtures and fuse blocks.
This calculator is not a replacement for the expertise of a electrical professional. Under no circumstances should this calculator be the only resource for selecting wire size or circuit protection. Any wire size or circuit protection recommended by this calculator should be reviewed for adequacy, before installation, by a professional applying the applicable industry standards.
Fuse Factory expressly disclaims responsibility for any use of this calculator that results in inadequate wire size or circuit protection.