Wire size
Submitted by GotOurFish on Sat, 2024-09-07 13:16
Hi everyone, I have mounted the battery in the front of our boat (429 stacer) but I'm having trouble determining the wire size I need to run to the motor. I have looked at the wire charts but I can't determine the wire size I need as for the life of me I can't find how many AMPS the starter draws. Motor model is 1030A11FL and wire run is 6m one way, any advice is much appreciated.
SeperateKnob
Posts: 664
Date Joined: 28/11/16
Is that a 30hp?
Is that a 30hp?
GotOurFish
Posts: 13
Date Joined: 20/02/22
Yes 30hp 2 stroke, going to
Yes 30hp 2 stroke, going to upgrade eventually to 40 4stroke but will be a while
SeperateKnob
Posts: 664
Date Joined: 28/11/16
Is that a 30hp?
Is that a 30hp?
SeperateKnob
Posts: 664
Date Joined: 28/11/16
For a 40HP four-stroke
For a 40HP four-stroke outboard engine with a 6m cable run to the engine, determining the appropriate gauge cable depends on the current draw of the engine and the acceptable voltage drop. Four-stroke outboards generally draw between 20-30 amps for starting.
Assuming a 30 amp current draw and a typical acceptable voltage drop of 3% (for a 12V system), you'd likely need the following:
4 AWG cable for the positive and negative runs.
This size should handle the current over the 6m run with minimal voltage drop and ensure proper performance during engine startup. If your setup requires higher safety margins or longer runs, you might consider thicker cable.
dmck
Posts: 429
Date Joined: 07/03/19
DO NOT, under any circumstances...
.. use tha aluminim body as the negative wire. (or worse still--- the positive wire..)
My calculations are close to the above, but I'd go for either 3 AWG (26mm squ) or the "over the counter" 25MM sq.
Cable lugs are sold as cable thickness with diameter of bolt hole, eg SC25-10 takes a 25 squ mm cable and has a 10mm hole in it
DO NOT attempt to solder the cable to the lug, if you dont have a correct crip, borrow one!!