To fuse or not to fuse ?

Discussion in 'Motorhome Chat' started by mojo, Sep 6, 2013.

  1. mojo

    mojo Funster

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    Just had my 1000w inverter wired up by my dealer workshop .I already fitted the inverter in place ,they did the electrics part. It looks a tidy job with the wiring run under the van in a conduit about a 1mtr in legnth .I dont see a in line fuse,should there be one ?
     
  2. hilldweller

    hilldweller Funster Life Member

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    Yes - as close as possible to the battery.
     
  3. mojo

    mojo Funster

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    I will speak to them,what size fuse shall I insist on ?
     
  4. jonandshell

    jonandshell Funster

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    200 Amp!
     
  5. pappajohn

    pappajohn Funster Life Member

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    at max power you will draw 83amps so 100amp fuse to prevent unnecessary blowing..
     
  6. mojo

    mojo Funster

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    Im no sparky but that sounds a huge fuse
     
  7. Fireman Sam

    Fireman Sam Funster

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    It might be in a small fuse carrier where the cable connects to the battery.
     
  8. mojo

    mojo Funster

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    100 sounds better
     
  9. pappajohn

    pappajohn Funster Life Member

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    it is a huge fuse....about the same size as a box of matches

    same sort of thing the 'boy racers' use to protect their massive amplifiers
     
  10. mojo

    mojo Funster

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    Just got off the phone to them.Yes ,it turns out to be located on the battery box , a 70amp ceramic .
     
  11. pappajohn

    pappajohn Funster Life Member

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    not good enough.

    as i said, maximum power will be 83amps
     
  12. mojo

    mojo Funster

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    Will speak next week to up it to 100.
     
  13. hilldweller

    hilldweller Funster Life Member

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    Theory:

    1000 / 12 = 83A

    But in practice you need much bigger for surges.

    Basically the fuse protects the wiring so if it shorts out it goes not catch fire.

    So you need 100A min for the load but with heavy cables they would easily blow 200A if shorted.

    150 or 200 gets my vote.

    Remember, you plug in 1000W and the poor battery tries to find 100A ( remember losses in the inverter ) with a mighty "WTF is going on, 100A, you can't be serious". It won't say it for long, that you can be sure of.
     
  14. hilldweller

    hilldweller Funster Life Member

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    Not big enough.

    So that brings into question the cables, have they skimped on those too ???
     
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  15. Techno

    Techno Funster Life Member

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    My 1800watt is fused at 250 amps as recommended by Sterling
    [​IMG]
     
  16. pappajohn

    pappajohn Funster Life Member

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    curious Andy, what is the .75mm flat twin for.

    it appears to disappear directly inside the inverter next to the right hand socket outlet.
     
  17. Techno

    Techno Funster Life Member

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    Hi John
    That's not a flat twin. The cable I believe you mean is ribbon cable to the remote inverter on off switch
    [​IMG]
     
  18. Reallyretired

    Reallyretired Funster

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    My 1500w (3000w peak) inverter has a 300A fuse, but as I have two batteries the cable linking the batteries has a 150A fuse, working on the basis that each battery should carry half the load (batteries are identical and bought together). Seems to work.:thumb:
     
  19. pappajohn

    pappajohn Funster Life Member

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    that would explain it....though it does look like .75 flat twin.

    bearing in mind i'm viewing on a 7" tablet :Doh:
     
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