Blown Fuse on Inverter

SouthAfrica75
SouthAfrica75 Solar Expert Posts: 36 ✭
in General Solar Power Topics #1
1st time connecting 2 batteries in parallel to my 1200 watt power inverter.

However after connection everything and moving one battery box it blew the 300 amp fuse I have inline to the inverter from the battery.

Any thoughts as to why it would do this ?

Also where in the world can I get a replacement fuse?
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Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #2
    Re: Blown Fuse on Inverter

    Was the inverter on and running a heavy load (2kW or more, or starting a large electric motor)?

    Or, was the inverter wired backwards to the battery bank?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    #3
    Re: Blown Fuse on Inverter
    Also where in the world can I get a replacement fuse?
    Here's a link to Class T fuses available from NAWS, this site's sponsor: http://store.solar-electric.com/infubr.html

    HTH,
    Jim / crewzer
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  • SouthAfrica75
    SouthAfrica75 Solar Expert Posts: 36 ✭
    #4
    Re: Blown Fuse on Inverter

    1. Inverter was not turned on.

    2. After that happened I double checked to make sure I did not cross any
    connections.

    This is how it's connected.

    I have the positive from the inverter to positive on battery no. 1 and the negative from inverter to negative on battery no. 1.

    I then have a cable from positive on battery no. 1 to positive on battery no. 2and a cable from negative battery no. 1 to negative on battery no. 2
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #5
    Re: Blown Fuse on Inverter

    You are sure you blew the fuse moving the battery box?

    Could the fuse still be good and something else be wrong?

    Did you see sparks? Feel the fuse get hot?

    Did the two cables touch together somewhere or did the terminals touch at the inverter while moving the box?

    Have you gotten the inverter working since the "fuse problem" yet?

    -Bill :confused:
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • SouthAfrica75
    SouthAfrica75 Solar Expert Posts: 36 ✭
    #6
    Re: Blown Fuse on Inverter

    I have used the inverter to test it out when I first got it with just one battery and it worked just fine.

    Today I wanted to boost the amp hours and went out and got another 105amp hr battery to connect in parallel.

    I connected everything and turned on the inverter and it worked.

    I then moved the battery box to the position I wanted it and then heard 2 popping noises with sparks and then the inverter was dead.

    I removed the fuse and sure enough it is blown.

    I doubled checked and no positive to negative bare wires touched. Could and insulated pos to neg wire cause it... I doubt it.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #7
    Re: Blown Fuse on Inverter

    You may have to look closely, but look for burned / heated areas were there is exposed metal from the Positive lead of the fuse to any negative metal/connection/etc. Should be pretty obvious with 300 amps of 12 volts going through it.

    You really need to find the shorted area so you can mechanically prevent it from happening again.

    12 volts will not go through insulation--but a sharp strand of wire or metal burr on a connector can easily puncture the insulation...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #8
    Re: Blown Fuse on Inverter

    Make sure BOTH batteries are at the SAME voltage before you connect them together.

    Charge both independently, so that they are fully charged.

    Check with a volt meter, possibly the new one got reverse charged at the factory or warehouse.

    Two batteries at the same voltage, should not spark, not even a little bit. If one was lower than the other, that could explain a heated wire, but not blowing the inverter fuse.

    And wear safety goggles till you find out what went zap. Don't want battery acid blowing up in your face if it still goes wrong again.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • SouthAfrica75
    SouthAfrica75 Solar Expert Posts: 36 ✭
    #9
    Re: Blown Fuse on Inverter

    Thanks guys for the suggestions.

    Both are 12v batteries.

    I'm going to start from one end to the other and check anything that may be wrong with the cable wires.

    Also going to check the charge in each

    Ordered 2 new fuses today which will be here next week so I can recheck.
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  • Windsun
    Windsun Solar Expert Posts: 1,164 ✭✭
    #10
    Re: Blown Fuse on Inverter

    Some of the cheaper inverters have all the negatives and grounds bonded to the case, so if the case was touching something you may have gotted a short that way.
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  • SouthAfrica75
    SouthAfrica75 Solar Expert Posts: 36 ✭
    #11
    Re: Blown Fuse on Inverter

    Whats still confusing me is why when I connected everything it was ok, but when I went to move the battery boxes into the position I wanted them is when it started to spark and blow the fuse.

    Also when I had 1 battery connected, nothing happened and it worked when tested.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #12
    Re: Blown Fuse on Inverter

    Probably what happened is that you have very heavy (large diameter) wires. They are so stiff, that when you moved the (relatively) heavy battery box around, you were bending cables and twisting connections--and something touched.

    With the battery disconnected,     trace the positive lead from the output of the fuse (assuming the fuse is in the positive circuit) to the inverter positve connection and check every point were it runs near grounded metal, near the negative lead, and where there are bare terminals (as well as any metal cases around the inverter. You may need a good light, magnifying glass, and possibly a small mirror to find where it shorted. You can also try (carefully) sliding your hand along the positive run/terminals and feel for anything sharp or strange (missing insulation, etc.).

    It is also possible that a washer, coin, some cable strands left behind, or something else fell into the inverter terminal box and got vaporized...

    In any case, you should identify where/what happened so that you can protect yourself against it happening again.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • SouthAfrica75
    SouthAfrica75 Solar Expert Posts: 36 ✭
    #13
    Re: Blown Fuse on Inverter

    Bill

    I appreciate all your suggestions.....

    My set-up is in an outside small storage closet (5' x 4') made of wood. Inverter is attached to the side of the cabinet and the batteries sit ontop of ceramic tile that I placed on the floor of this closet. There is no metal of any kind around the batteries, cables of inverter that could short it out. I also double checked my ground wire to make sure it's not touching a positve anywhere.

    I've gone ahead and recharged both batteries as someone suggested, I've run my hands along all cables hoping for a piece of wire to pinch my hand but nothing all is smooth.

    I've thought about the coin deal shorting out, but that would have happened when I 1st put this to the test with one battery.

    Well, I will wait until I get my replacement fuses before I can retry, making sure I dont have to move the thick cable around. I don't want to blow another $20.00 fuse....
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  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    #14
    Re: Blown Fuse on Inverter

    SA75,

    The battery wiring described earlier is not optimal. I recommend the batteries be connected as shown in the diagram below, courtesy of Trojan Battery. Note that the leads to/from the inverter are connected to diagonally opposite terminals on the batteries. This helps to evenly distribute voltage drops and currents across both batteries and the interconnecting cables.


    Parallel Connect
    con_02.gif
    To increase amp-hour capacity,
    connect batteries in parallel.

    HTH,
    Jim / crewzer
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  • SolarJohn
    SolarJohn Solar Expert Posts: 202 ✭✭
    #15
    Re: Blown Fuse on Inverter

    Since you were unable to locate any wiring problem, I guess it's possible that something inside the inverter shorted out. If that's the case, you're going to blow the new fuse as soon as you apply power to the inverter. Maybe it would be best to send the inverter in for repair, saving you the cost of a $20.00 fuse. The repair tech should tell you what was done to fix the inverter. If they find nothing wrong, except a blown fuse, then you'll know that you probably created a short as you moved the battery box.

    John
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #16
    Re: Blown Fuse on Inverter

    Before you blow another fuse--if the short is still present--use a large 12 volt light bulb (like a car head lamp or something similar) across the fuse block (with the inverter turned off--or at least no load).

    If the bulb does not light (of only glows dimly)--then at least the short is no longer present and you won't pop another $20 fuse.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • rplarry
    rplarry Solar Expert Posts: 203 ✭✭
    #17
    Re: Blown Fuse on Inverter

    Southafrica
    You also might want to consider using a circuit breaker in place of a fuse. The initial cost is more but if you start blowing a few fuses, then the breaker will pay for itself pretty quickly.
    Larry
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  • crewzer
    crewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    #18
    Re: Blown Fuse on Inverter

    A 175 A circuit breaker should be about right. If considering a CB instead of a fuse, remember to spec a DC rated model.

    Here's an example: http://store.solar-electric.com/obdc-175.html
    Here's a complete breaker box with breaker: http://www.midnitesolar.com/MidNite%20Mini-DC.html

    CBI (Circuit Breaker Industries) is located in SA and manufactures DC rated CB's. You might be able to find something locally.

    See: http://www.cbibreakers.com/

    HTH,
    Jim / crewzer
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  • SouthAfrica75
    SouthAfrica75 Solar Expert Posts: 36 ✭
    #19
    Re: Blown Fuse on Inverter

    Ok............

    I connected everything as per Trojans schematic for paralell. I then used a 12 v test light accross where the fuse should be and it lights up like a christmas tree and kept on burning bright.

    Does this mean that all is ok because it completed the circuit without blowing out the bulb or getting any sparks or ????
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  • rplarry
    rplarry Solar Expert Posts: 203 ✭✭
    #20
    Re: Blown Fuse on Inverter

    SA
    If the inverter is turned off, then it means that there is still a short. If the inverter is on then the test light should be on and that does not tell you anything, it might still be shorted.
    Larry
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  • SouthAfrica75
    SouthAfrica75 Solar Expert Posts: 36 ✭
    #21
    Re: Blown Fuse on Inverter

    I must then have a MAJOR short in my inverter...... that all I can think of.

    But why when I first tried this about a month ago when I had just one battery it worked just fine and now all messed up.

    The test light continues to shine in the on and off position of the inverter.

    I even disconnected and just used 1 battery and still the same thing.

    Just wasted $200.00 on an inverter I guess.

    This system is costing more and more each day....... A nice quite hoda generator would have been better
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  • SouthAfrica75
    SouthAfrica75 Solar Expert Posts: 36 ✭
    #22
    Re: Blown Fuse on Inverter

    And to add that when I 1st connected all batteries nothing shorted.

    It just happened when I moved those darn battery boxes

    :grr:grr:grr:grr:
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #23
    Re: Blown Fuse on Inverter

    i'll throw my comments here, but first i am wondering what is the make and model of your inverter? i am also wondering lastly if the inverter is still under warranty?

    reminding you of what naws said, "Some of the cheaper inverters have all the negatives and grounds bonded to the case, so if the case was touching something you may have gotted a short that way." now what you said, "Inverter is attached to the side of the cabinet". now i'm assuming that to be a metal cabinet and once the inverter is bolted to it the entire cabinet is of the same potential as the inverter casing is and is usually - thus allowing for a short potential to the cabinet too. was the inverter attached to that cabinet when first tried, but recheck any wires shorting to the cabinet anyway.
    the ultimate test would be removing the inverter and 1 battery to be test connected outside your intended cabinet with nothing else there but 1 battery and 2 wires to connect to your inverter. if it shorts then and all was connected properly (observing proper polarities) then i'd say the inverter is at fault.
    good luck
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  • SouthAfrica75
    SouthAfrica75 Solar Expert Posts: 36 ✭
    #24
    Re: Blown Fuse on Inverter

    Well after all that I figured what was the culprit.

    I removed the inverter from the side of the wood cabinet and noticed that the positive lead was bent and touching the inverter creating the short.

    I guess when I moved the battery box around i moved and bent the cable thus touching the inverter.

    I repositioned the inverter in the storage cabinet and also wrapped the end of the positive lead in a good amount of electrical tape so if it were to bend again it would not short out.

    Hopefuly no damage to the inverter one the fuse arrives and I can give it another try and ready for Hurricane Season.

    Thank you all.... you've allbeen a great help on here getting me going again. :D
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #25
    Re: Blown Fuse on Inverter

    now i stand corrected on the cabinet as it is wood, but i am assuming that you found that short when going to try it outside of the cabinet. good thing you found the problem rather than having to send the inverter back for another and you can now make provisions to insulate that area so as it won't accidentally happen again.:cool::D
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