Trolling Motor Wire Size
Trying to figure out trolling motor wire size can be a little daunting, particularly with all the various technical terms and calculations to get your head around. But once you know the voltage and amps of your motor, it can be a little easier.
We have put some information together to help you better understand some of the electrical terms, as well as how to choose the correct size of wiring and circuit breakers for your trolling motor system.
Wire Gauge, Amperage, Volts And Breakers Explained
Wire Gauge
Wire gauge, or AWG (American Wire Gauge), is a term used to refer to the area of the cross section of a round wire and relates to the circular mil area. One circular mil refers to the diameter of a circle, with the cross sectional area of a wire being equal to its diameter squared (circular mil area).
The larger or thicker the wire, the lower the AWG number. Usually when you’re choosing your wire, the longer it is in length, the lower awg rating you’ll need, as you’ll need the wire to be thick enough to compensate for the extra length.
Amperage
The amperage draw of your trolling motor is how much power or current it draws from your battery. The amps that your motor draws can be used to determine the size of circuit breaker you will need for your system.
The pound thrust rating of your trolling motor can be used to work out how many amps it draws. You can calculate this by dividing the pound thrust by the voltage and multiplying that by 12.
Volts
The volts that your trolling motor uses will usually help you to determine the size of wire gauge and circuit breaker to use. Most trolling motors for kayaks will be either 12 volt or 24 volt. With a 12 volt motor, you’ll need one 12 volt battery. With a 24 volt motor, you will need two 12 volt batteries.
Voltage is basically the current that’s flowing from your battery to the motor. This is generally known as DC (Direct Current) as the current is flowing in a straight line directly from the battery to the motor. This is unlike AC (Alternating Current) that we find in our homes via the power outlets in the walls.
Breakers
A circuit breaker helps to protect the electrical circuit from damage due to an overload of current. The circuit breaker effectively stops the power if the level of current is too high.
A circuit breaker is required for many trolling motors as the US Coast Guard regulations state that you must have a circuit breaker or fuse installed to protect any ungrounded current-carrying conductor.
Generally, your circuit breaker should have a higher amperage rating than your motor so that it’s able to sufficiently handle the level of current that is passing through it.
For most kayak trolling motors you’ll probably need either a 50 amp or 60 amp circuit breaker, depending on the amperage draw and voltage of your motor.
What Is The Best Gauge Wire For 12-Volt And 24-Volt Trolling Motor Batteries?
Many trolling motors can be used with 8 gauge wire, however, the length of wire you need and the amperage of your motor can alter the size of wire you need. For example, if you need a longer length of wire, you’ll likely need a lower gauge and therefore thicker wire.
Your trolling motor manufacturer should recommend the ideal awg size to use with your particular trolling motor. But we have put together a table with the amperage rating of common trolling motor sizes for kayaks so that you can get a better idea of the size of wire to use based on the length you need, as well as the recommended size of circuit breaker.
Wire Gauge And Circuit Breaker Size Guide
Cell | Amps drawn | Circuit Breaker | 5 ft length | 10 ft length | 15 ft length | 20 ft length |
12 volt | 30 | 50 amp | 10 awg | 10 awg | 8 awg | 6 awg |
12 volt | 42 | 50 amp | 10 awg | 8 awg | 6 awg | 4 awg |
12 volt | 50 | 60 amp | 8 awg | 6 awg | 4 awg | 4 awg |
24 volt | 42 | 50 amp | 10 awg | 10 awg | 8 awg | 8 awg |
Last Words
Now that you know a little more about what some of the technical terms mean you should hopefully find it easier to work out the size of wire that you need for your trolling motor set-up.
Remember that the awg rating of the wire will possibly change depending on the length of wire that you need and you will likely need a thicker, lower gauge wire the more powerful your motor is. It can also be useful to keep in mind that the size of the circuit breaker should be enough to handle the amps of your motor.
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