Page 1 of 2 12 LastLast
Results 1 to 20 of 28
  1. #1
    Member
    Join Date
    May 2013
    Location
    Hudson River, NY
    Posts
    3,857

    melted wires on my 2021 36V Ultrex

    So my 36V Ultrex just left the shop again this afternoon and it appears the main wires to the motor (located within the tube) melted together and shorted out. What the hell would have caused this on a 1 year old unit? They shorted one and other about 6" up from where they connect to the motor or lower unit itself. Burning completely through the hot wire. Also why didn't it trip my circuit breaker at the battery? Crazy what I've gone through with this TM in the short time I've owned it.

  2. Electrical/Wiring/Trolling Motors Moderator CatFan's Avatar
    Join Date
    Jun 2004
    Location
    SW Indiana
    Posts
    26,089
    #2
    Are you running on high for long periods?
    If you have integrity, nothing else matters. If you don't have integrity,
    nothing else matters.​

  3. Member
    Join Date
    May 2013
    Location
    Hudson River, NY
    Posts
    3,857
    #3
    I had run the motor on spot lock for two days prior while there was a steady 20 mph wind. It was on almost non stop. It's as though the hot wire got so hot that it melted through it's jacket and then into the negatives casing triggering the dead short and burn out. When it went I was on high and in open water cruising to another spot. I probably should have mentioned this is on an electric motor only rig. So pretty much non stop trolling motor.

  4. Member
    Join Date
    May 2008
    Location
    Pierre Part, La
    Posts
    4,295
    #4
    As John said. It ran on high speed continuously for to long a period. No Troll Motor made will operate for long periods of time under those conditions.

  5. Member
    Join Date
    Apr 2008
    Location
    Lakeview,AR.
    Posts
    7,994
    #5
    Brad, shouldn’t the breaker go if he is pulling enough Amps to melt those wires? There could be a breaker issue or too big of a breaker.
    Tell me where has a slow movin' once quick draw outlaw got to go

  6. Electrical/Wiring/Trolling Motors Moderator CatFan's Avatar
    Join Date
    Jun 2004
    Location
    SW Indiana
    Posts
    26,089
    #6
    Quote Originally Posted by bobcoy View Post
    Brad, shouldn’t the breaker go if he is pulling enough Amps to melt those wires? There could be a breaker issue or too big of a breaker.
    Nope. MK warns against sustained operation above 85%.
    If you have integrity, nothing else matters. If you don't have integrity,
    nothing else matters.​

  7. Member
    Join Date
    Apr 2008
    Location
    Lakeview,AR.
    Posts
    7,994
    #7
    That is what they said about Lithium batteries. Is it the same recommendation for other types as well? I know you can pop the breaker if run in heavy weeds fo 20 min or so. It seems a bit risky that the breaker would not pop with the wires melting. I can see things getting toasty, but burn through the hot wire. I would be asking some questions when I brought it in for warranty service. Plenty of warranty left on the motor. Those recommendations said nothing about voiding any warranty. JMO Bob
    Tell me where has a slow movin' once quick draw outlaw got to go

  8. Member fishnfireman's Avatar
    Join Date
    Apr 2005
    Location
    Amarillo
    Posts
    12,446
    #8
    Quote Originally Posted by bobcoy View Post
    That is what they said about Lithium batteries. Is it the same recommendation for other types as well? I know you can pop the breaker if run in heavy weeds fo 20 min or so. It seems a bit risky that the breaker would not pop with the wires melting. I can see things getting toasty, but burn through the hot wire. I would be asking some questions when I brought it in for warranty service. Plenty of warranty left on the motor. Those recommendations said nothing about voiding any warranty. JMO Bob

  9. Member
    Join Date
    May 2008
    Location
    Pierre Part, La
    Posts
    4,295
    #9
    Bob
    John is correct on the warning about Minn Kota.
    I am not saying I am correct on this, below, but It is my opinion on how it works.
    As far as the output of the Minn Kota board, it is a square wave DC signal. You change the amplitude of the signal to change the speed of the motor. You will not read voltage on the board with the motor not connected. At full speed on the motor, with a load, you are putting 36 volts on the motor continuously or in this case you attempting to Keep the boat in a certain spot with a 20MPH wind. I am not sure of the current on the output of the board on this, but I do know that it will not pull enough current on the input to trip the breaker because the motor is sort of free spinning with resistance of the water. I have measured this on a Fortrex 80 and it pulled 30 amps on the input , at full speed, with just water. I did not measure the output.
    In grass different story. You run your motor in grass you are bogging down the motor and creating the affect of lock rotor current which is essentially the same as putting a block of wood on the prop to stop the motor from turning. At this point you are causing the motor to draw max amps which is greater than a 60 amp breaker an it will trip the breaker.
    The reason for burning the wires from the control board to the motor is, you are exceeding the 30 amp rating of #10 wire and therefore melting the insulation of the wire. You then ask why they don't use larger wire , like #4 or 6. The reason under normal operation you will never exceed the amp rating of the wire. That is why the have the warning. 2nd reason is try to rung 2 #6 and MDI cable and a ground through a tube the size of the one they use. They would have to go bigger on the tube size.
    Hope this helps. Jus my opinion.

  10. Member
    Join Date
    Apr 2008
    Location
    Lakeview,AR.
    Posts
    7,994
    #10
    I will go back and read the FAQ’s again. Have not done that for a couple years. Still say the breaker should be sized to protect the motor from meltdown no matter why the wires get hot. JMO Bob
    Tell me where has a slow movin' once quick draw outlaw got to go

  11. Member
    Join Date
    Apr 2007
    Location
    Salem, Ohio
    Posts
    1,946
    #11
    Quote Originally Posted by bobcoy View Post
    I will go back and read the FAQ’s again. Have not done that for a couple years. Still say the breaker should be sized to protect the motor from meltdown no matter why the wires get hot. JMO Bob
    I would agree with this statement.!! Breaker should be sized to protect the wires as well.

  12. Member
    Join Date
    Apr 2012
    Location
    Insomnia, near Seaford Delaware
    Posts
    35,516
    #12
    The wiring from the plug through the motor is only 10 gauge usually. It just will not handle that amount of current on high for extended periods of time.

  13. Member
    Join Date
    Feb 2018
    Posts
    3,153
    #13
    Fuses/breakers are sized to protect the wire to a device. Not necessarily the device itself. Now there is nothing to stop a maker from either integrating a fuse/breaker within a component or derating the wiring circuit to help protect the device itself.

  14. Member
    Join Date
    Feb 2018
    Posts
    3,153
    #14
    If conditions are just right a chafed wire can draw enough current to produce enough heat to melt a wire without tripping a breaker. 36 volts at say 20 amps is a lot of power.

  15. Member
    Join Date
    Apr 2008
    Location
    Lakeview,AR.
    Posts
    7,994
    #15
    If the OP is still around, What size breaker and where is it located.(how many feet of wire between) What size wire as well and what is your power supply. Volts and type. Bob
    Tell me where has a slow movin' once quick draw outlaw got to go

  16. Member
    Join Date
    May 2013
    Location
    Hudson River, NY
    Posts
    3,857
    #16
    My circuit breaker is a 60 amp located about 6" from the battery. The cables are approx 20' long and are 6 gauge... it's 36 volt Vmax Tanks

  17. Member
    Join Date
    Apr 2008
    Location
    Lakeview,AR.
    Posts
    7,994
    #17
    Should be good, but for kicks you might want to run it on 9. That uses the PWM circuitry and 10 does not. By the way I cant find the Minn Kota statement on running flat out with regular (lead acid)batteries. The only one I have seen was about Lithium and they pretty much ok’d use of Lithium with a caution of going full out at 10. I would also say one of the outboard or transom mount electrics might get more speed being in the back and pushing(might get the bow up just a bit and that will mean less water drag. I still feel there should be a fuse or something to keep from melting wire. Did you have MK fix it for you? Bob
    Tell me where has a slow movin' once quick draw outlaw got to go

  18. Member
    Join Date
    May 2013
    Location
    Hudson River, NY
    Posts
    3,857
    #18
    MK did the repair under warranty. I was excited to get it back in the water and went out the other day just me and my dog... Pushed off, hit the pedal, and the bastard spun in reverse!!!! I Can Not Win with this motor

  19. Member fishnfireman's Avatar
    Join Date
    Apr 2005
    Location
    Amarillo
    Posts
    12,446
    #19
    Quote Originally Posted by chsapeak View Post
    MK did the repair under warranty. I was excited to get it back in the water and went out the other day just me and my dog... Pushed off, hit the pedal, and the bastard spun in reverse!!!! I Can Not Win with this motor
    Not the motors fault---wired backwards by ASC

  20. Member
    Join Date
    Apr 2012
    Location
    Insomnia, near Seaford Delaware
    Posts
    35,516
    #20
    Might have installed the magnet assembly backward.


    Unless it's an old 5 speed you cant wire the T/M backward, but you could if you mix the two up at the top of the shaft or down at the motor. It sounds like you are dealing with an apprentice repairman.

Page 1 of 2 12 LastLast