trolling motor wire size and fuses

[JSGOLD]

I have an old Minn Kota 65MX that came with our boat and it was wired by previous owner with no fusing that I can find.(It has wires running directly from the battery to a small power center but I see no fuses on the main wires). what is proper fuse sizing on one of these? I know little about it but some research showed 20-30 amp draw max. 40 or 50 amp fuse or breaker perhaps? I was thinking of putting an inline fuse near the battery in case of short.

 

[JB]

Re: trolling motor wire size and fuses

A 40 amp circuit breaker is what I always used on my 55lb and smaller MKs. I used #4 or #6 wires; they just can't be too big.

 

[JSGOLD]

Re: trolling motor wire size and fuses

I will d/c asap but it seems it was 10 guage thhn wire he had on that hookup. I know 10 guage is rated for 30 amps for AC voltage but I will switch up a size and fuse it at 40 amps. thanks!

 

[fishrdan]

Re: trolling motor wire size and fuses

I know 10 guage is rated for 30 amps for AC voltage but I will switch up a size and fuse it at 40 amps.

Current capacity of the wire is not the big issue, voltage drop across the wire is. Switching up to 8ga from 10ga wire won't cut it (unless it's a very short wire run), you need to go up to #6 or #4. The length of the wire run plays a big part in selecting the correct size wire. Run through this wire size calculator and see what you come up with, I would shoot for a max voltage drop of 10%.

http://beta.circuitwizard.bluesea.com/#

A fuse or breaker within 1' of the battery is nessasary, as you mentioned. I would go a bit bigger on the fuse/breaker than what the motor's max current draw is, so you don't pop it if you stall out the motor. IE; if the max draw is 42 amps, go with a 50 amp breaker.

Dig up a shcematic of your trolling motor, it might list the max current draw (all of the schmatics I've looked up have had it. Check fish307.com and see if they have a schematic for your TM.