Why do electric troller's need such thick guage wiring?

[wpg manitoba]

The typicall trolling motor off the top of my head uses maybe 600 watts? and has maybe 6 or 8 guage wires. If this were an ac product it would have 16-18 guage wires.
Can anyone explain why dc powered products need such a thicker guage wire compared to ac?

 

[JB]

Re: Why do electric troller's need such thick guage wiring?

To make 600 Watts, a 115VAC product draws about 5.2 amps. To make the same 600 Watts a 12VDC device needs to draw 50 amps. That is ten times the current used by a 115VAC device. That is why it needs big wire.

 

[Alumarine]

Re: Why do electric troller's need such thick guage wiring?

To make 600 Watts, a 115VAC product draws about 5.2 amps. To make the same 600 Watts a 12VDC device needs to draw 50 amps. That is ten times the current used by a 115VAC device. That is why it needs big wire.

Yep, as JB said. Volts x Amps = Watts

 

[Silvertip]

Re: Why do electric troller's need such thick guage wiring?

This is also why high voltage overhead transmission lines carrying thousands of AC volts can be pretty small gauge wire in comparison to the supply line feeding your house..

 

[bruceb58]

Re: Why do electric troller's need such thick guage wiring?

Also, for the same current, the number of volts dropped is the same be it 12VDC or 110VAC. For example, a 2V drop is a greater percentage of 12V than 110V.

 

[jhebert]

Re: Why do electric troller's need such thick guage wiring?

The current drawn is only a secondary consideration. The real reason for very large cable size is to reduce the voltage drop. In distribution of power at 12-Volts, if the distance is more than about ten feet, the conductor size must be selected to minimize the voltage drop. This results in a conductor that is considerably larger than the minimum conductor needed to carry the current. Calculation of the size of a conductor based on current rating in 12-Volt power distribution will lead to very poor results. You must calculate the conductor size based on voltage drop. This is why the trolling motor power wiring must be so large.