is 12 gauge wire fat enough for my trolling motor?

[mchin]

I'd like to relocate my trolling motor plug closer to the bow of my boat, and I have a good amount of 12 gauge maine wire. Is this wire ok to use? The length of wire I would need is about 3-4 feet. The trolling motor is a 30 lb thrust minnkota and this is a 12 volt motor.

 

[Dunaruna]

Re: is 12 gauge wire fat enough for my trolling motor?

That's a circuit extension of 8 feet. The 12ga will struggle.

Simply double up the wires or buy some 10ga.

 

[John_S]

Re: is 12 gauge wire fat enough for my trolling motor?

Simply double up the wires.

If I remember correctly, that is a bad idea. The wires will not be identicle, and one will have slightly more resistance than the other. Over time, one wire will tend to carry most of the current, heat up and degrade, causing the load to switch to the other wire which will start to do the same.

Just buy some 8ga and be done with it.

 

[ENSIGN]

Re: is 12 gauge wire fat enough for my trolling motor?

Use at least the same gauge wire as what's on the trolling motor,to small a wire will just heat up and act like a resistor.In this case(size matters)!!!

 

[JB]

Re: is 12 gauge wire fat enough for my trolling motor?

Even though a 28lb motor will not draw a huge amount of current I recommend 6ga wire. That is pretty standard factory wiring for trollers.

 

[halas]

Re: is 12 gauge wire fat enough for my trolling motor?

Gang 3 X 12 ga. wires together if you have a lots of them will, do the job fine
without voltage drop or over heating. Make sure the circuit is fused, if not add an inline fuse 60 Amp (I did mine with 40 and it has not blown yet).

 

[BeaufortTJustice]

Re: is 12 gauge wire fat enough for my trolling motor?

This chart will give you a basic guideline. It is commonly used in the car audio world, but I see no reason it can't be carried over to the boating world:

First determine the maximum current flow through the cable (looking at the amplifier's (trolling motor) fuse is a relatively simple and conservative way to do this).
Length of run (in feet)
Current 0-4 4-7 7-10 10-13 13-16 16-19 19-22 22-28

0-20A 14 12 12 10 10 8 8 8
20-35A 12 10 8 8 6 6 6 4
35-50A 10 8 8 6 6 4 4 4
50-65A 8 8 6 4 4 4 4 2
65-85A 6 6 4 4 2 2 2 0
85-105A 6 6 4 2 2 2 2 0
105-125A 4 4 4 2 2 0 0 0
125-150A 2 2 2 2 0 0 0 00

Columns (AWG wire size) are a bit misaligned, but still usable. Hope this helps.

 

[Silvertip]

Re: is 12 gauge wire fat enough for my trolling motor?

A 30# thrust motor will draw about 30 amps. 12 gauge wire is not rated to carry that load. As for current switching wires -- that can't happen. Current flows from the positive post of the battery to the motor and back to the negative terminal of the battery. It can't reverse itself. Wire size on the POS side of the circuit must be capable of carrying the load. The ground side of the circuit must be at least the same size as the POS side but can be larger.

 

[NYBo]

Re: is 12 gauge wire fat enough for my trolling motor?

Current flows from the positive post of the battery to the motor and back to the negative terminal of the battery.

Electrons have a negative charge. Current flows from negative to positive.

 

[Barnacle_Bill]

Re: is 12 gauge wire fat enough for my trolling motor?

http://www.eskimo.com/~billb/amateur/elecdir.html

 

[NYBo]

Re: is 12 gauge wire fat enough for my trolling motor?

http://www.eskimo.com/~billb/amateur/elecdir.html

I stand (well, sit) corrected. At least, I think I am. But we are talking about electric flow through solid conductors, so I'm not sure. At least I think I'm not sure...:redface:

 

[bruceb58]

Re: is 12 gauge wire fat enough for my trolling motor?

Over time, one wire will tend to carry most of the current, heat up and degrade, causing the load to switch to the other wire which will start to do the same.

LOL Now that's a new one I haven't heard. Curious, What do you think every individual strand of wire is doing in a wire. Are you saying that eventually only one strand of wire is going to take all the current because that is sure what you are implying?

 

[Silvertip]

Re: is 12 gauge wire fat enough for my trolling motor?

Neg to Pos or Pos to Neg has been hotly debated for ages. Don't think it has ever been settled but interesting topic if you are inclinded to waste some time. If it was neg to pos, then we really should be installing switches in the NEG side of the circuit -- Not?????????

 

[halas]

Re: is 12 gauge wire fat enough for my trolling motor?

In the electronic equations it is excepted that direct current flows from positive to negative. It is a theory that was established to be able to calculate complex circuits. In reality the current flows from the negative to the positive. The one way traveling of negative electrons = direct current

 

[boat1010]

Re: is 12 gauge wire fat enough for my trolling motor?

Smiling... I doubt that he cares which direction it goes. Just is the wire big enough.

 

[mchin]

Re: is 12 gauge wire fat enough for my trolling motor?

thanks for all the help, 8 gauge it is, the last thing I want on my boat is a fire or the chance of getting shocked because I was too cheap to buy some wire. I may have to snake it or run it outside of the rails, but that that's fine.

Thanks for all the input.

 

[whofan]

Re: is 12 gauge wire fat enough for my trolling motor?

thanks for all the help, 8 gauge it is, the last thing I want on my boat is a fire or the chance of getting shocked because I was too cheap to buy some wire. I may have to snake it or run it outside of the rails, but that that's fine.

Thanks for all the input.

I went to my local electric supply store and bought some 6ga wire by the foot. I made up my own harness and backed it with a 40amp (manual reset) circut breaker. I run a 55pound Minnkota AP.

 

[halas]

Re: is 12 gauge wire fat enough for my trolling motor?

I went to my local electric supply store and bought some 6ga wire by the foot. I made up my own harness and backed it with a 40amp (manual reset) circut breaker. I run a 55pound Minnkota AP.

I like the heavier wire also and to me it does not have to be the expensive marine grade in a boat that is kept dry.
I like to make my own harness also with inexpensive heat shrinking tubes from Harbour Freight, running it in the orange flexible conduit from Home Depot.

 

[John_S]

Re: is 12 gauge wire fat enough for my trolling motor?

LOL Now that's a new one I haven't heard. Curious, What do you think every individual strand of wire is doing in a wire. Are you saying that eventually only one strand of wire is going to take all the current because that is sure what you are implying?

Except you are not talking wires woven together, which do act as one conductor. We are talking about two seperate paths, with two seperate connections. The current will follow the path of least resistance.

You may want to laugh at it, go ahead, but please provide a better explaination why it is NOT an accepted practice in any wiring, be it car, boat, house, etc? Please enlighten me.

Then talk to your electrician. See if he upgrades a 15 amp 14ga wired outlet to 20 amps by adding a 2nd run of 14ga, which would be cheaper than installing 12 ga.

 

[John_S]

Re: is 12 gauge wire fat enough for my trolling motor?

As for current switching wires -- that can't happen. Current flows from the positive post of the battery to the motor and back to the negative terminal of the battery. It can't reverse itself.

Unless I'm mistaken, he is refering to having two positive wires and two negative wires to one device. Ie doubling up the two 12 ga to get a larger current capacity. Thats a big NO NO. But if you have a better explaination as why, I would like to hear it. No one said anything about current reversing itself.