24 volt wiring help

Discussion in 'General Electronics Chat' started by tdp, May 7, 2013.

  1. tdp

    Thread Starter New Member

    May 7, 2013
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    Hi there, I was wondering if someone could take a look at this wiring diagram I have put together and let me know if you see any problems or issues with it. I have a 24 volt system with 2 sets of 12 volt batteries and 2 - 24 volt motors.

    https://www.circuitlab.com/circuit/ejm7dq/circuit-1/

    I had some issues with the wiring the first time I tried to hook it up and ended up frying about $800 worth of motors. They are currently in the shop and the diagram shows how I have the system wired now. I am getting the correct voltage at the plugs for both motors.

    Thanks for you help and time.

    tp
     
  2. gerty

    AAC Fanatic!

    Aug 30, 2007
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    How did you damage the motors?
    If it were mine, I would use a double pole switch(one set of contacts for each motor).
     
  3. tdp

    Thread Starter New Member

    May 7, 2013
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    I was really hoping someone could answer that for me. When I hooked it up and neither motor worked, I pulled the switch out and noticed the wiring behind it.

    I have 2 red wires coming from each fuse and 2 whites coming to the motor from the switch. When i pulled the switch out, I noticed a red and a white on each terminal of the switch, instead of the 2 reds on one side and the 2 whites on the other like I would have expected to see. One motor seemed to run ok on its own, but as soon as I hooked the 2nd motor up, both motors were knocked out.

    Any ideas as to what could have happened? Did I inadvertently get 48 volts to them in some way?

    I really want to make sure I have this fixed before I get the motors back from the shop.

    Any issues with the circuit diagram as I have it?
     
  4. gerty

    AAC Fanatic!

    Aug 30, 2007
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    What size motors?
    How many amps do they need?
    How much current is your switch rated for?
    What kind/size batteries are you using?
    We need more info to give you a proper answer, it may be as simple as the batteries are too small for the motors and cannot supply enough current.
     
  5. tdp

    Thread Starter New Member

    May 7, 2013
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    This is a 24 volt trolling motor situation and running 4 deep cycle marine batteries.

    The switch involved is basically a single pole battery disconnect switch.
     
  6. tdp

    Thread Starter New Member

    May 7, 2013
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    Assuming that all the batteries, switches, fuses, etc are the correct size, is there anything in the just the way I have it wired that would cause issues?
     
  7. gerty

    AAC Fanatic!

    Aug 30, 2007
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    If it's wired exactly as shown, you shouldn't get 48 volts across the motors. That leads us to what is the damage to the motors, and what went wrong. I still stick by my initial assessment of a 2 pole switch.

    I recommend checking the polarity of all your connections.
     
  8. gerty

    AAC Fanatic!

    Aug 30, 2007
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    Since you haven't told us how the damage occured, we don't know if the fuses are the correct size. A fuse should blow before damage occurs, that is their purpose.
     
  9. gerty

    AAC Fanatic!

    Aug 30, 2007
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    Are these batteries connected, in any way, to the boats
    wiring/charging system?
     
  10. tdp

    Thread Starter New Member

    May 7, 2013
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    Well like I said, it's hooked up like this now. When the motors fried (the circuit board fried, according to the shop), it had a red wire from the fuse and a white wire from one of the motors on each side of the switch. I don't know if this makes a difference.

    And yes it is hooked up to the on board chargers on the boat, they were hooked up but not plugged in at the time.
     
  11. tdp

    Thread Starter New Member

    May 7, 2013
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    This set up had been working fine with one motor and I decided to add another and that's when the trouble started.
     
  12. tdp

    Thread Starter New Member

    May 7, 2013
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  13. gerty

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    Aug 30, 2007
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    From what I can see there would be 48 volts across the 2 motors that are in series.If the motors are the same, the voltage would divide equally. Did this thing come from the factory with 2 motors and 4 batteries?
     
  14. tdp

    Thread Starter New Member

    May 7, 2013
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    No this isn't a factory set up. It's a custom job.
     
  15. gerty

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    Aug 30, 2007
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    Another situation here is two battery banks wired in parallel. While true they are only parallel when switch is closed, batteries/motors would have to be identical in charge and load to keep one from trying to charge the other.
    This issue isn't a real problem until one motor or battery goes bad. Here again, the double pole switch would eliminate that problem.
     
  16. tdp

    Thread Starter New Member

    May 7, 2013
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  17. tdp

    Thread Starter New Member

    May 7, 2013
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  18. sheldons

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    Oct 26, 2011
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    Here is how your motors could be wired using a dpdt switch....
     
  19. gerty

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  20. gerty

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    Aug 30, 2007
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    Doesn't have to be double throw..
     
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