Boat wire poll

I'm going to have to run wire while I've got the rear decks out (good opportunity) and it's easy to drill holes, run conduit, etc.

So I gotta fairly quickly pick a gauge of wire for a trolling motor and order it in while I'm doing the trailer. Trolling motor is likely going to be a bow mount Minn Kota Maxxum 55 with 42 inch shaft and variable speed. Boat length is 17 foot front transom to bow. Boat will have MK trolling motor socket (mounted on bracket) and locking plug. Most likely a 50Amp fuse in line.

Please select a gauge wire and if you're not satisfied with the available choices, select larger or smaller and please say what gauge you would use and why in a post.

Also welcome any suggestions on conduit and other wire protection stuff available cheaply/inexpensively at Lowe's, HD or Walmart, etc.

I would do this myself, but I've got a sinus infection with a secondary infected tooth and I'm too zonked on pain killer right now to think for myself. Can't even sleep, hurts too much. If you fellas can help me out, I would greatly appreciate it. I suspect this infection issue problem isn't going away anywhere near as quick as I would like it to.

Thank you,

Dave

1st - if you are looking to save money avoid Home Cheapo, Lowes and Walmart for this sort of stuff. They tend to sell everything pre-packaged and the price per foot for the wire and conduit is excessive.


Go to a local hardware store where they can sell you the exact amount of material that you need and even answer questions with some knowledge.


That being said, the longer the run (length) of wire the heavier the gauge needed to avoid problems. You might even consider using marine grade wire 9which is tinned to prevent corrosion)


To properly determine the gauge you need to know what teh draw will be - obviosly a trolling motor is going to draw more then a light and same for the FF



Length (feet): Determined by measuring the length of the conductor from the positive (+) power source connection to the electrical device and back to the negative (-) power source connection. Note that the power source connection may be either the battery, panelboard or switchboard.

Current (amps): Determined by adding the total amps on a circuit.

Conductor sizes not covered in Table C or Table D may be calculated by using the following formula:

After calculating the Circular Mil Area (CM), use Table B to determine the proper conductor size (National Fire Protection Agency and Coast Guard require that the next larger conductor be used when the calculated CM area falls between two conductor sizes).

CM=K x l x L / E

CM = Circular Mil area of Conductors
K = 10.75 (Constant representing the mil-foot resistance of copper)
I = Current - amps
L = Length - feet
E = Voltage drop at load (in volts)
For Example...
Q: For example: A bilge pump draws 10 amps. The positive run is l l feet from the power panel, including the float switch. The negative run is only 10 feet. What size wire?

A: Use the formula to reach the correct answer:

CM = 10.75 x 10 (amps) x 21 (total length of run) / 0.36 (3% of 12v) = 6,271

Table "B" shows that 12 AWG wire has a CM area of 6,500 and is the correct choice. However, SAE wire has a CM area of only 5,833. Under NFPA and USCG regulations, 10 SAE wire must be used.



Here is the link to the table:

https://www.cncphotoalbum.com/doityourself/wiring/wiring.htm

I beleive I remember you having a 17' boat...... I think capt. gave and excellent description of use for ya... I would go with 6.

If you are running your wires more than 6', I would go with 4ga wire.

One of the best places to get your wire is https://www.genuinedealz.com. They will also put the ends on for you (which will NOT rust).

Honestly though, I would go with the largest diameter wire you can go with. It will let your motor work less hard to get the amp it needs, especially if you are going to be making long runs in high speed. I tried using 6 once on a run that was about 10' long, but my motor kept getting hot. I switched it over to 4ga wire, and it cooled down considerably.

Hey Dave, just got done my root canal for the same thing so I'm feeling ya, well I will be once the numbness wears off.

As said above, 6 or 4ga, which ever will fit inside you plugs. Ironic that the troller uses 8 or 10 on the pigtails though...

Jamie

Ranchero50 said:

Ironic that the troller uses 8 or 10 on the pigtails though...

Click to expand...

I think that gauge is fine for that lenght of run, and it's meant to be hooked straight to the battery. If there are going to be a longer run, breakers and all that other stuff, a larger wire will help compensate for the loss.

I used 6 gauge wire from my 55lb MinnKota on the bow to my battery in the stern (15 ft).

I found an extra long 6ga set of jumper cables and clipped off the ends. Made for a neat set-up in my 14'. Now I ran this under my deck out of the way and put lugs on the bat end and made it neet and tidy and all and everthing not shoddy nor nothing like that at all or nothing. I swear. It looks good. Yeah. Fused it too. Liquid tape over the shrink tubing after soldering with the solder gun ( Weller Jr.) my x-father-in-law used on Air Force One during the Eisenhower Admin. All True. The Weller Jr. is made of bakelite. Still works has two head lights. It does. Yes. Da jumper cables are a good way to go if it's Sunday and ain't nothing much open but Wal-Mart you can run down to AutoZone and lay out 40-50 bucks for 20' 4ga thick double insulated wires and run-em bout anywhere in the boat without worry about grounding nor nothing cause them baby's are thick and stuff. They got this black line down one side so you can keep the (-) and the (+) stright in your head but if when you try your trolling motor out and it goes backwards you probley got it wrong anyway.

Ranchero50 said:

Hey Dave, just got done my root canal for the same thing so I'm feeling ya, well I will be once the numbness wears off.

As said above, 6 or 4ga, which ever will fit inside you plugs. Ironic that the troller uses 8 or 10 on the pigtails though...

Jamie

Click to expand...

I wish I was already past the root canal. I'm going in to see the dentist this morning. It's 3:36AM and I'm in too much pain to sleep (again), my face is swelling up and I'm generally miserable. If it gets any worse, I'm driving myself to the hospital and asking for something stronger for pain.

Yeah, those manufacturers know you gotta get the supply to the trolling motor and once reasonably close, the wire they have attached will do the job.

the 6 gauge is they way that most boat companies run the wire from the batteries to the plug