Solar Fuses - Do I Or Don't I Use Them?

Discussion in 'Solar Power' started by jac-in-a-box, Jun 24, 2015.

  1. jac-in-a-box

    jac-in-a-box Read Only Funster

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    Just about got everything I need for my instal apart from some dry weather and fuses!

    Depending on where I go for information I'm left a little uncertain about fusing needs. Should I fuse between the panels and controller, some say yes and some say no.
    If I do need to fuse should the fuse be at the panel or controller end?
    More importantly what fuse size and should I fuse both positive and negative inputs?

    I've got two 150w panels which will be connected in parallel.
    Panel specs:
    Max V 17.8V
    Max A 8.43A
    Open circuit V 22.3V
    Short circuit A 9.1A

    Controller is the one used by Andy, Techno 100. 25A/300W MPPT by Maximum Solar

    Understand the need to fuse between the controller and fuse close to the battery terminals. I've got 2 x 100ah (traction type I believe) batteries for leisure use. I also have a pair of midi fuse holders to fit, but what size fuse do I fit there?

    All advice gratefully recieved:)
     
  2. Techno

    Techno Funster Life Member

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    The supplied instructions say no
     
  3. jonegood

    jonegood Funster

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    Andy I note on your photos that you have the same mppt regulater as lots of us.

    Sorry if you ve been asked this a thousand times before; but what do the wires from your 'load' terminals go to?

    Ive tried searching but you have a lot of posts.

    Jon
     
  4. Munchie

    Munchie Funster Life Member

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    I run my CO and LPG alarms from the load terminals!
     
  5. jac-in-a-box

    jac-in-a-box Read Only Funster

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    Without digging around just now, I'm certain that I've seen photo's of your instalation with fuses Andy...I could easily (and probably) be wrong though!

    Fuse size at my batteries anyone?
     
  6. Techno

    Techno Funster Life Member

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    Feeds a 12volt socket adjacent
     
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  7. Techno

    Techno Funster Life Member

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    Yes I use a fuse but its not necessary
    Fuse to batteries needs to be bigger than your max output 25amp is fine
     
  8. jac-in-a-box

    jac-in-a-box Read Only Funster

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    ^^^ Thank you Sir!
     
  9. jonegood

    jonegood Funster

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    Thanks

    Jon
     
  10. Gromett

    Gromett Funster

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    I personally fuse anything capable of generating a spark. My solar panels have a fuse on the roof for that just in case situation. I fused both ends of the cable running from my battery to my solar controller. Only fused the positives.
     
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