circuit breaker question

[starcraft1982]

hello.so i have a 24v trolling motor.originally,it had a black 20a breaker on neg. terminal and red 20a on the positive(the way i bought boat).well of course i kept popping 20a so i went and got a 50a.put it on positive wire.left the 20a on ground wire.obviously,this was wrong as again lost trolling motor,reset 20a and went on half speed rest of day on electric only lake.anyway on electric only lake i would like to run full(some).so question is,do i need another 50a on neg. wire or can i just take 20a off of neg. and connect w/out?thanks and please excuse my electrical ignorance.just wanna go w/out it shutting down.

 

[Silvertip]

Re: circuit breaker question

Ummm -- we have no idea if you have a 12 volt or a 24 volt or a dual voltage 12/24 volt motor so step one is to determine that. Do you have one battery or two. If you have one battery you have a 12 volt motor and you should not have, nor do you need a circuit breaker in the negative lead. If you have a 24 volt ONLY motor with two batteries in series you also do not need a breaker in the negative lead. If you have a 12/24 volt motor then the wiring gets more complicated but the fact remains, if a 20 amp breaker blows on one side of the system, a 20 amp breaker will pop on the other side. The reason one popped and the other didn't is because of the slight difference in ratings. One 20 amp breaker may pop at 20 amps, while the other pops at 19.5, 20.5 or even 21 or 22. So without any more information that's the best we can do.

 

[starcraft1982]

Re: circuit breaker question

it is a minn kota auto pilot 65lb.thrust(@2004)w/universal sonar.there are 2 batteries.bridged w/cable from pos.of one to neg.of other.then motor connected to pos.of one and neg. of other.boat is 1988 cajun so im assuming the 20a on terminal wires were for a 12v system(more likely in 1988).has 1-10 speed selector and pops breaker on anything higher than 6or7 speed.sorry,w/out papers on TM,im personally not sure if its a 24v,or a 12/24.i would guess a 24v as i dont see a switch to switch between 12v and 24v like on my dads motorguide.again correct me if im wrong.ive always had a 12v 36lb autopilot on my fishing boat(alot older TM)and is my first w/24v power.i want to know about it,i just dont yet.thanks

 

[John_S]

Re: circuit breaker question

20A sounds low for a typical 12V or 24V motor. Before increasing it to the right value for your MK 65lbs (probably 40-50A), you will need to know the wire size and approximate length, to see if it can handle the additional current.

 

[Silvertip]

Re: circuit breaker question

At 65# it is a 24 volt motor and the battereis are wired in series. You do not need a breaker in the jumper between batteries nor do you need one in the negative lead. A 24 volt 65# motor draws about 40 amps so six gauge wire in all parts of the system is fine as is a 50 amp breaker in the positive lead.