Circuit Breaker Question

[Dan180cc]

Hello to all, Currently I am putting my Battery back into my boat after the winter storage. I have a 12v trolling motor 55lb Minn Kota power drive, Im not sure what the current requirement is for it, my boat came pre wired for a 24v motor. this is not a big deal but I noticed when I hooked up the battery that the circuit breaker was for a 24v system. Am I doing the wrong thing by connecting up a 12V system using a 24V breaker?

 

[Paul Moir]

Re: Circuit Breaker Question

The 55lb Minkota draws 45 amps max at 12v.<br />Circuit breakers don't "know" what voltage they're running, so your 24v one will work on 12v (or 6v for that matter).<br /><br />Hope this helps!

 

[ChrisMcLaughlin]

Re: Circuit Breaker Question

Voltage times current equals watts.<br />If your voltage is 12 and your current is 45 then your wattage is 540.<br />If your voltage is 24 and your current is 45 then your wattage is 1080.<br />There is a difference in circuit breakers and in wire size. A smaller size wire, with the proper insulation class, can carry more power (wattage).<br />If you have any doubts, please refer the job to a qualified outfitter as you might have a meltdown.

 

[Paul Moir]

Re: Circuit Breaker Question

I was going to write something about the wires, but then I figured if he's asking this about breakers, he probably isn't going to start swapping them out for higher amp ones himself. And since the ones that came with his boat are sized to the wires that came with the boat. And breakers aren't watt-limiting-devices... <br /><br />You see my point?

 

[Dan180cc]

Re: Circuit Breaker Question

Circuit breakers work as current limiting device dont they. I have run the trolling motor and nothing seems to have gotten hot yet. I made sure the wing nuts are tight. All wiring and breakers are factory installed. Should I be concerned about anything else?<br /><br />I do have one more question. My battery is inside a plastic box that strapps to the floor with a canvas belt. The belt is tight holding the box inplace but there is room inside the box that allows the battery to move about 1 inch. I was told to spray some expanding insulation foam inside the box to fix it. Does this sound like a good idea or is there a better way. My block of wood does not seem to work to well. Thanks Dan.

 

[Paul Moir]

Re: Circuit Breaker Question

Yup, as long as the circuit breaker that came with the boat is rated to go off at higher than 45A, you are fine. <br />I would hesitate to use expanding foam. For one thing, it might be a little hard to ever get your battery out. <br />For another, that box is supposed to contain any spills from your battery. It won't do that very well if it's filled with foam. <br />What I've done in the past is cut some fairly thick pieces of regular styrofoam (bead board) and wedged them in between the battery and box.

 

[SingleShot]

Re: Circuit Breaker Question

All are correct, I will just add this note, You never want to put a 12v rated device on 24v systems but you are always safe the other way around. The voltage rating is usualy refered to for the contacts used. This is where wattage or volt/amps is seen. Breakers are current limiting as stated above. They can come in various trip ratings based on time/current curves. This is mostly for High power systems. Breaker size is important as in physical size. You may see a rating as Fault current rating. This is the amount of current that will pass before the circuit opens. If the available fault current is greater than the breaker rating you have the posibilty of the breaker exploding. This realy doesn't apply hear but is worth noting. You will be fine with what was supplied as long as the breaker is rated for the wire after it and the load placed on it.<br /><br />SingleShot