chris.olson
Petty Officer 2nd Class
- Joined
- Mar 15, 2009
- Messages
- 173
There was another thread on using circuit breakers for trolling motors. But that got closed because somebody asked a question on an old thread.
The post is pasted here:
Yes, dragging up an old thread, but this is the same situation I am in, except I am one step further into it. I have a 14' Valco aluminum boat with an outboard and a transom mounted trolling motor.
I have a battery mounted near the bow (for weight distribution) and have run 6 gauge wiring to that back of the boat where it is connected to the trolling motor wiring. The battery is in a Minn Kota Power Center battery box that has a 60 amp breaker built into it. I took the trolling motor off of the transom to get it out of the way while I was working on the outboard.
I went to put the trolling motor back onto the transom to go boating and tried to turn it on and it didn't work. I noticed that the handle was about halfway between OFF and 1 (forward). Probably got nudged there when I set onto the floor of the boat.
I opened up the trolling motor to look around and it wasn't pretty. Two of the wires from the controller heading down into the mast had obviously got hot and melted insulation. I removed the prop and got into the lower unit and the armature was black, the brushes were stuck in their mount, and several wires had the insulation burnt completely off of them. There was a black gooey tar like substance present and the small was definitely of something that was burnt.
SO, while the 60 amp circuit breaker absolutely protected the 6 gauge wiring from the battery back to the trolling motor, and the wiring going into the trolling motor (maybe 10 gauge?), it did nothing to protect the wiring in the trolling motor itself (which is smaller that the wiring from the battery and the trolling motor external wiring). Going forward (and considering the information in the preceding posts), I am wondering if I could install an additional fuse to protect the trolling motor wiring somewhere in or near the trolling motor to protect it should I find another way to put it in jeopardy?
What size (30 lb thrust motor) fuse?
And where should it be located?
Do NOT use circuit breakers on a trolling motor unless it is a manual reset breaker. Use an appropriately rated fuse. Auto-reset breakers, by design, will trip, the bimetal strip in them cools and it resets and goes back to smoking the internal wiring in the trolling motor itself until the breaker heats up again and trips. It will continue until it destroys your trolling motor or sets it on fire.
If you can get a manual reset breaker, then fine. Otherwise use a Maxi Fuse on trolling motors. The fuse should be at the battery if the only thing on the circuit is the trolling motor, and that fuse should be sized to the maximum amp draw of the motor in the specs. If the circuit powers other stuff then fuse the circuit at the battery, appropriate for the size of wire to the downstream fuse panel. Fuse each individual load circuit at the fuse panel.
The only unfused circuit in a boat should be the engine starting cables for the starter, and those should have a heavy duty appropriately rated master disconnect switch at the battery that is easily accessible in the event of an onboard fire or malfunction in the starter circuit (like a stuck starter selenoid). If that master switch is in a compartment containing a fuel tank then it must be ignition-protected.
Adhering to the above will generally keep you in compliance with USCG regs as long as you use marine cabling. I've also seen automotive wire, and even extension cord wire, used in boats which is not legal, even in recreational boats. There is also limitations on the sizes of wire used on branch circuits (18 AWG minimum) from fuse panels, and number of connections per terminal (four max). But those generally aren't regulated tightly on recreational boats unless you set your boat on fire, in which case you'll probably find yourself being self-insured if the boat wasn't wired to USCG regs.
The post is pasted here:
Yes, dragging up an old thread, but this is the same situation I am in, except I am one step further into it. I have a 14' Valco aluminum boat with an outboard and a transom mounted trolling motor.
I have a battery mounted near the bow (for weight distribution) and have run 6 gauge wiring to that back of the boat where it is connected to the trolling motor wiring. The battery is in a Minn Kota Power Center battery box that has a 60 amp breaker built into it. I took the trolling motor off of the transom to get it out of the way while I was working on the outboard.
I went to put the trolling motor back onto the transom to go boating and tried to turn it on and it didn't work. I noticed that the handle was about halfway between OFF and 1 (forward). Probably got nudged there when I set onto the floor of the boat.
I opened up the trolling motor to look around and it wasn't pretty. Two of the wires from the controller heading down into the mast had obviously got hot and melted insulation. I removed the prop and got into the lower unit and the armature was black, the brushes were stuck in their mount, and several wires had the insulation burnt completely off of them. There was a black gooey tar like substance present and the small was definitely of something that was burnt.
SO, while the 60 amp circuit breaker absolutely protected the 6 gauge wiring from the battery back to the trolling motor, and the wiring going into the trolling motor (maybe 10 gauge?), it did nothing to protect the wiring in the trolling motor itself (which is smaller that the wiring from the battery and the trolling motor external wiring). Going forward (and considering the information in the preceding posts), I am wondering if I could install an additional fuse to protect the trolling motor wiring somewhere in or near the trolling motor to protect it should I find another way to put it in jeopardy?
What size (30 lb thrust motor) fuse?
And where should it be located?
Do NOT use circuit breakers on a trolling motor unless it is a manual reset breaker. Use an appropriately rated fuse. Auto-reset breakers, by design, will trip, the bimetal strip in them cools and it resets and goes back to smoking the internal wiring in the trolling motor itself until the breaker heats up again and trips. It will continue until it destroys your trolling motor or sets it on fire.
If you can get a manual reset breaker, then fine. Otherwise use a Maxi Fuse on trolling motors. The fuse should be at the battery if the only thing on the circuit is the trolling motor, and that fuse should be sized to the maximum amp draw of the motor in the specs. If the circuit powers other stuff then fuse the circuit at the battery, appropriate for the size of wire to the downstream fuse panel. Fuse each individual load circuit at the fuse panel.
The only unfused circuit in a boat should be the engine starting cables for the starter, and those should have a heavy duty appropriately rated master disconnect switch at the battery that is easily accessible in the event of an onboard fire or malfunction in the starter circuit (like a stuck starter selenoid). If that master switch is in a compartment containing a fuel tank then it must be ignition-protected.
Adhering to the above will generally keep you in compliance with USCG regs as long as you use marine cabling. I've also seen automotive wire, and even extension cord wire, used in boats which is not legal, even in recreational boats. There is also limitations on the sizes of wire used on branch circuits (18 AWG minimum) from fuse panels, and number of connections per terminal (four max). But those generally aren't regulated tightly on recreational boats unless you set your boat on fire, in which case you'll probably find yourself being self-insured if the boat wasn't wired to USCG regs.