Power to new 24 vt motor

[traveler]

Finally took the plunge and got a new 24 vt Minnkota. Couple questions...the plug in the bow is only 2 prong, dealer doesn't have a matching male end for the motor; can i just eliminate the plug and wire it directly, or should I buy both ends from the dealer and try to install the new female end in the boat (doesn't look like it will fit right off)? I've read I need a fuse in the line...the manual says "a 60 amp manual reset circuit breaker". I guess I have to do it like the manual says, but, again, dealer doesn't have one, and I haven't seen anyone on here mention it in tons of discussion. At least the mounting of the motor look straightforward...thanks

[Hookmaster]

You will enjoy your new motor. Don't wire it directly. You want to be able to unplug the trolling motor when charging the batteries. If you can, try and find the matching male end. Maybe try another marine store or a Fleet Farm type of store. There are only a few manufacturers. If you can't find it, then by a new pair. Go with a resettable breaker mounted at the battery. The 60 amp ones are hard to find exept for the MinnKota brand which are very expensive compared to the 50 amp ones. I've been using a 50 amp one with an 80# thrust motor and it has never tripped even when running close to max power.

[PierBridge]

What kind of Minnkota motor is it and how many wires "prongs"

Your going to want to slow way down here if you hook up the 12 volt feed "if there is one" incorrectly you will FRY your board.

The correct plug should used.

[traveler]

Thanks hookmaster, I'll see if I can find a 60 amp first... the motor is an 80 lb, 24 vt., Riptide ST, copilot, autopilot...I spent $$$, so I'll go reeeeely slow:) The 2 wires coming off the motor are simple red/black with pigtail ends that will of course need to be removed. The boat is a 2000 Champion Bay boat; the female plug in the boat currently is 2 prong, which seems like all the motor needs as it only has 2 wires. However, the couple plugs I looked at at the local marine dealer had 3 prongs, why, I don't know. The only bigger/more complex motor out there would be this same type, only 36 vt/101 lb thrust. There is also a seperate wire with what looks like a transducer plug end...don't know why it's even there, as I didn't buy one with universal sonar.??

[Hookmaster]

How many wires go to the female plug from the batteries. If it is more than 2 the female is probably a 12/24 connection. Then I think you need the 12/24 male counterpart. If it is only 2, then you can use one that has 2 prongs/wires.

[BobT]

I would be careful about just throwing a 60A circuit breaker or fuse on the system. If the wire isn't sized to handle this current load you may find yourself testing your fire extinguisher.

Bob

[Whoaru99]

From what I've seen, a 50A breaker is the max for 8ga wire, 80A is the max for 6ga wire.

Of course, using a smaller breaker on larger wire is OK - just not the other way around.

Besides fuse/breaker sizing, choosing the proper gauge wire is important to minimize voltage drop since voltage drop just wastes power as heat.

For instance, say that you need a 50A circuit. Well, strictly by ampacity, 8ga wire is OK.

However, assuming a 16ft boat and a a few extra feet for routing, the voltage drop is over 6%. That's too much, IMO. Stepping up to 6ga cuts the voltage drop to about 4%. Going one more step to 4ga cuts the voltage drop to about 2.5% Generally, for non-critical circuits, I've seen recommendations of 5% or less voltage drop.

[traveler]

60 amp is straight out of the manual so it should be good. I'll have to see what size wire runs back to the panel from the plug. I talked to MinnKota today and they said with the 24 vt motor the 2 wire plug is fine. Thanks for the responses guys.

[Whoaru99]

Sure, I believe you that 60A is straight out of the trolling motor book.

However, I assume the wire is already in the boat and that is what dictates the maximum size circuit breaker you should use - not what the trolling motor book says.

[traveler]

I see what you're saying. Now how do I determine what gauge wire is in the boat?

[Cabela10]

Quote:

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I see what you're saying. Now how do I determine what gauge wire is in the boat?

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It should say right on the insulation covering the wire. It should be really thick and stiff. The thicker the wire, the better gauge the wire is.

[Whoaru99]

Perhaps you'll get a break and it'll be on the wire but, IMO, that's 50/50 chance.

You could look up "wire gauge table" on the Internet and you should get information listing the diameters. The numbers listed will be diameter of the bare conductor, not the insulation.

Another option would be to contact the boat manufacturer and ask them.

[Cabela10]

My wires actually say "6-gauge" right on them, so who knows, I guess I'm wrong. ha ha.

[Whoaru99]

Well, actually, I still say 50/50 chance. My wires say nothing on them.

I've found mine to be 8ga using measurement and comparison to other wire samples.