What guage of wire for my inverter.

Discussion in 'Trucking Electronics, Gadgets and Software Forum' started by RLIGHT276, Jun 30, 2009.

  1. tedcohen

    tedcohen Light Load Member

    May 2, 2008
    Portland, Maine
    The keys to efficiency of any inverter are 1.) the gauge of the wire used and 2.) the length of the run.

    To wit, use the largest gauge wire you can.

    And use no longer a wire than you need, because the longer the wire, the less efficient your inverter will be.
  2. 112racing

    112racing Road Train Member

    Nov 30, 2008
    pocono's, pa
    THE FUSE SHOULD BE AS CLOSE TO THE BATTERY AS POSSIBLE because having the fuse 3-4 feet away if the wire shorts you will have a fire if you go online to theinverterstore or donrowe they have inline fuses and short jumper wires with the terminals already attached as well as complete wiring kits like i said do it right or it will cause problems or a fire
  3. RLIGHT276

    RLIGHT276 Light Load Member

    Jul 10, 2008
    Altoona Pa
    Yes I got all of that but what I am asking do I need to put an inline fuse on both of the power wires goin to the battery and do I need to hook up one power wire and one negative wire to one battery and the other power wire and negative wire to another battery.My cobra 2500 watt inverter has 2 power hook ups and 2 negative hook ups.
  4. lostNfound

    lostNfound Road Train Member

    Jun 28, 2007
    Home of the Stampede
    If you do use two power wires to source, then you should use two fuses ... kinda defeats the purpose of the fuse if you don't.

    I have a 2500 w inverter as well. I spliced the two power wires together a few inches from where they connect to the inverter. I then finished the run to the batteries with 0 gauge welding cable. I didn't connect directly to any battery, but to a terminal on the cable connecting all the batteries. I did the same for the negative cables.
    RLIGHT276 Thanks this.
  5. RLIGHT276

    RLIGHT276 Light Load Member

    Jul 10, 2008
    Altoona Pa
    So let me get this right,you run a cable out of each terminal on the power side say about 8 inches spliced them together then run them both to the inline fuse that is about 8 inches away from battery then spliced them into a cable running into the battery on the positive side and do the same for the negative side except for running in inline fuse.What size of inline fuse should I use for the 2 positive cables.
  6. 112racing

    112racing Road Train Member

    Nov 30, 2008
    pocono's, pa
    from the cobra 2500w users guide;

    8 Nothing Comes Close to a Cobra™ 9
    Connecting Cables (not included)
    Power wire and wiring are very important to the
    performance of the inverter. Because the inverter has a
    low voltage, high current input, low resistance wiring is
    essential between the battery and inverter. This is so it
    can deliver the maximum amount of energy to the load.
    Use only copper wire. Aluminum wire has about one-third
    more resistance than copper wire of the same size, plus it
    is difficult to make good, low-resistance connections to
    aluminum wire.
    We recommend #4 AWG copper cable (90°C insulation
    rating) as the minimum size for connections between
    the battery and inverter.
    Keep the cable length as short as possible, no more
    than four feet (one and a half meters). This will keep the
    voltage drop to a minimum.
    If the cable has too much voltage drop, the inverter may
    shut down when drawing higher currents because voltage
    at the inverter may drop below 10 volts. If you must use
    longer cables, choose thicker cables, such as #2 AWG,
    and trim the ends of the cable to fit the terminals.
    To connect the cables between the
    inverter and the battery:
    1. Press the Power Button on the inverter to the off
    position. If the power source is a DC power supply,
    switch it off as well.
    2. On the end of the cable that connects to the inverter,
    strip back the insulation about one-half inch (one and
    one-half cm), exposing the bare copper conductor.
    3. Connect cable to the Power Input Terminals on input
    end of the inverter. The red terminal is positive (+) and
    the black terminal is negative (-). Insert the bare ends
    of the cables into the terminals and tighten the screws
    to clamp the wires securely.
    It is a good idea to check and tighten these screws
    from time to time. They can become loose by
    vibrations or thermal cycling.
    4. Connect cables to the power source:
    a. Connect the cable from the Negative (Black)
    Terminal of inverter to the Negative Terminal
    of the power source. Make a secure connection.

    We recommend a main fuse in the
    battery's positive cable to protect against DC
    wiring short circuits (external to the inverter).
    The fuse should be as close to the battery as
    possible. We recommend a Buss Fuse ANL-250
    or equivalent. The specific fuse ampere rating
    should be sized to allow operation of all your
    DC powered equipment.

    [FONT=Arial, Helvetica, sans-serif]You may want to also order a 6" piece of red battery cable to connect the fuse holder to the battery...
    [FONT=Arial, Helvetica, sans-serif][FONT=Arial, Helvetica, sans-serif]
    TFB200 - 200 Amp Class T fuse & holder
    [/FONT] [FONT=Arial, Helvetica, sans-serif]The Battery Fuse and Holder has a cover that protects from inadvertent contact with the battery fuse and posts, and the fuse is Class-T rated to allow for momentary surges without blowing. [/FONT][FONT=Arial, Helvetica, sans-serif]As current passes through any cable, heat is generated. If the inverter draws more current than the cable can handle due to heavy loads, excessive heat is produced. The fuse can handle a certain amount of excess current but is designed to blow when the safe limits are exceeded, protecting the cable from deterioration or permanent damage. [/FONT][FONT=Arial, Helvetica, sans-serif]Proper sizing of the cable and fuse are important in ensuring that these hazards are avoided. For [/FONT] ​

    • [FONT=Arial, Helvetica, sans-serif]DC rated, UL listed high current Class-T fuse[/FONT]
    • [FONT=Arial, Helvetica, sans-serif] Protective clear removable cover protects against inadvertent contact [/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Available in 200, 300, 350 and 400 amp models[/FONT]
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    • [FONT=Arial, Helvetica, sans-serif]Easy to change, user replaceable fuses[/FONT]
    [FONT=Arial, Helvetica, sans-serif]Specifications: [/FONT]

    • [FONT=Arial, Helvetica, sans-serif]Dimensions (HxWxD): 2.5 x 2.0 x 7.0" [/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Weight: 1.5 lb [/FONT]
    • [FONT=Arial, Helvetica, sans-serif]Hardware: 5/16" (on TFB200) [/FONT]
    • [FONT=Arial, Helvetica, sans-serif]3/8" (on TFB300, TFB350 and TFB400)[/FONT]
    [FONT=Arial, Helvetica, sans-serif]
    RLIGHT276 Thanks this.
  7. RLIGHT276

    RLIGHT276 Light Load Member

    Jul 10, 2008
    Altoona Pa
    Got another question about hooking up my inverter,I canot find anyting over an 80 amp fuse locally and was wondering if I run my wire from the positive side of the battery to the inline fuse and then run another inline fuse behind the first then finish running my cable to the battery would this work or no.I have no idea what else to do.any ideas or suggestions would be helpful.
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