Voltage drop occurs when the voltage at the end of a cable is lower than the voltage at the start. Every cable has a small amount of electrical resistance. As a cable grows in length, electricity has to travel through more cable and encounters more resistance along the way. This increased resistance causes the voltage to fall and can result in poor performance for connected electrical devices.
The amount of acceptable voltage drop varies depending on the type of connected device. Non-critical DC circuits, such as DC lighting, winches, and water pumps, can have up to 10% voltage drop without impacting performance. Critical loads, such as battery chargers, inverters, and fridges, are considered to have a 3% allowable voltage drop, although best practice is to aim for 1% (0.12V on a 12V system).
To avoid excessive voltage drop in your electrical system, there are a couple of steps you can take:
Minimise cable length
The best way to avoid voltage drop is to minimise the length of cable runs you are making. This can be done by ensuring that critical loads (battery chargers, inverters, etc.) are placed close to the battery. Keeping cable runs shorter will also allow you to use less cable and to use smaller cable, which will save you money.
Use the correct size cable
The size of cable you will need to use depends on the amount of current passing through and the length of the circuit. Circuits that are long or carrying large amounts of current will require thicker cables in order to avoid voltage drop. More information on choosing the correct cable size can be found here.
Ensure your connections are well made
Poor quality connections can create electrical resistance, which will result in voltage drop. Make sure that all connections in your electrical system are tight and that all connectors and lugs are well crimped. More information on how to make good electrical connections can be found here.
Comments
0 comments
Please sign in to leave a comment.