Fuse Change

[sbfishySC]

I currently have a 40 amp inline fuse running with my 10 AWG wiring and was informed by Minn Kota that my 10 gauge wire would work with my new 24v 70# trolling motor but I would need to put a 50 amp fuse on.

My question is can I just take the 40 amp fuse out of the holder and replace with a 50 amp fuse or do I need a new holder as well? If I need to replace the holder too, would I be better off with a 50 amp circuit breaker or stick with a fuse?

Thanks,

Stephen

[slonezp]

Yes. As far as going to a CB, it's 6 of one, 1/2 dozen of the other.  You can keep a couple spare fuses in your boat. There are auto and manual reset breakers available.

[J Francho]

Pretty much what slonezp said, but if you're popping 50 amp fuses, you might want to look into that.

[Team_Dougherty]

10 AWG wire should only be fused at 30 amps. To use a 50 amp fuse you should really upgrade to 6AWG wire. The reason you my be blowing the 40amp fuses in the motor is drawing more current to make up for the voltage drop because you are using 10 AWG wire.

[sbfishySC]

Thanks for the replies.

Not blowing any fuses at this point. Just upgrading a trolling motor and want to make sure I have everything suitable to run it.

[BKeith]

Not too sure why they told you #10 wire was large enough to run your TM, I totally don't agree with that. #10 will handle the 35 - 40 amps of the TM for a very short length but not the distance required for the TM without causing a noticeable loss in performance. Even on a 17 foot boat, you are looking at 35 - 40 feet total length of cable, you have to figure the length it take to go from the battery to the TM and back to the battery, so if it takes 20 feet to get from the battery to the TM, you have to double that because of the return path. Here's one of many guides http://www.bluesea.com/articles/1437, check it out and see if you really want to use #10 wire. I would also figure it for no more than a 3% drop. 10% would be approx. a 2.5 volt drop and that will slow the motor down.

Now, if you never plan to run the TM at full thrust, and never working at over approx. 1/2 thrust, the #10 will work.

[sbfishySC]

I replied to their email they sent me about the 10 gauge being ok to use under 20 feet asking if that was 20 foot one way or if I needed to calculate in twice that and if so, would 10 still work. Waiting on a reply from them to see what they say. 

 

Probably going to go ahead and upgrade the wiring just in case.

[Long Mike]

Personally, I would never consider the use of 10 AWG wire for a run of that length.  At minimum I would use 8 AWG.

[BKeith]

When I installed the 80# motor on my 20' boat, I upgraded from #6 marine cable to #2 marine/battery cable and put the #6 in my 14' jon boat. 

 

As a minimum, I would go with #6 marine/battery cable, and if you can afford it, I would even go with a #4 (it ain't cheap).   The marine/battery cable is a fine strand cable.  I would not try to use the stranded house wire you get a Home Depot/Lowes.    Here's one source that has pretty good prices http://www.pacergroup.net/Categories3.aspx?Id=6_AWG_UL_Battery_Cable&gclid=CNybkrTlsLkCFSgS7AodOUMACg, might check Cabela's and BPS, ebay, etc also.

 

You will probably have to go to a welding supply house to get the heavy terminal lugs, unless you happen to be lucky enough to have a parts store that carries them.  Some NAPA's have them but don't let your jaw hit the floor when they give you a prices.  NAPA is the 7/11 of the parts stores. 

[sbfishySC]

I replied to their email they sent me about the 10 gauge being ok to use under 20 feet asking if that was 20 foot one way or if I needed to calculate in twice that and if so, would 10 still work. Waiting on a reply from them to see what they say. 

 

Probably going to go ahead and upgrade the wiring just in case.

 

Got a reply and they clarified that the length they gave me was total length, both ways. So for me, running approx. 32 ft of wire, they would recommend #8 wire. Going to rewire with 8 AWG this weekend hopefully. Went 8 instead of 6 because I could get 8 cheaper obviously, and if 8 works, why spend that extra $$$ to get 6? Seems the general consensus I've been seeing around google searches and some here says that 8 works fine and is more commonly used. If I seem to have a major problem with #8, I'll upgrade to #6. 

 

I appreciate everyone's help.

[BKeith]

Once you do, there is a very simple test to see if it's large enough or not.  Take a DVM to the lake with you after you get everything installed, and take a friend to operate the TM.   Launch the boat, connect the DVM across the battery terminals the TM cables are connected to. Run the TM on high for a couple of minutes to give it time to pull the surface charge off the battery and the voltage stabalizes and make note of that voltage.  Now disconnect from there and connect the DVM across the connector the TM is plugged into and run the TM on high again a couple minutes, give it time to stablize and make note of that reading.   See what the difference in the two readings are, and figure you percentage of drop.    2.6 volts is going to be approx 10%.  that's 10% of lost performance.