Inverter problems

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I guess I should expect this but I'm having trouble with my inverter. It has worked flawlessly for 6 months and now I'm clueless as to what's happening. It's a cheaper Chicago electric msw inverter and I've used it sparingly to power chargers for my kids' toys, a tv on occasion, ect, and was all set to use my system for charging an electric scooter. Now when I turn it on I get a low voltage alarm and the unit shuts down. I checked the voltage on the batteries using a volt meter and my Xantrex meter, both putting the voltage at about 13.6v. Next I checked the volts at the input terminals of the inverter. 13.6v again. I've grounded the unit as the inverter's intruction's told me to and like I said, has worked great for about a half a year with never getting even warm. I've contacted the manufacturer and am waiting on a response with little hope. There are no external fuses to check and all wiring is tight and clean. Any ideas? :?

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  • Patman3
    Patman3 Solar Expert Posts: 62 ✭✭✭✭
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    Re: Inverter problems

    check the 12v voltage at the inverter input when you turn the inverter on. Does it drop for a second? Can you measure the current into inv, is it drawing any current. Make sure no AC load is on it when turning on. Use the same cables on another inverter?
  • System2
    System2 Posts: 6,290 admin
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    Re: Inverter problems

    The Xantrex meter is wonderful. When I start up the inverter itself alone, the draw shows on the meter shortly, then it drops off to close to zero when the inverter goes into protect mode. There is draw for a short moment, then the inverter goes dead, and so does the draw from the batteries. I'm begining to believe I should have gone with a "better" inverter. I'm going to try a smaller 400w inverter that I have tomorrow off the same batteries and see how it reacts. If there are no ill effects, it must be the inverter, right?
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
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    Re: Inverter problems

    shawn,
    many msw inverters of that type will put a fuse inside the inverter. i believe mine was soldered to the pc board and it was an automotive blade type at 30amps.
  • Brock
    Brock Solar Expert Posts: 639 ✭✭✭✭
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    Re: Inverter problems

    It almost sounds like the output side is either loaded or somehow shorted out since it is trying to draw a bunch of power on startup. If I had to gues I would say the inverter is bad. I just bought a relatively cheap 1200w xantrex inverter on ebay for $65. It tells you overall loading and input voltage.
    3kw solar PV, 4 LiFePO4 100a, xw 6048, Honda eu2000i, iota DLS-54-13, Tesla 3, Leaf, Volt, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • System2
    System2 Posts: 6,290 admin
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    Re: Inverter problems

    By chance, if there is something plugged into the inverter, is the ground wire in whatever that item might be, connected to the neutral conductor?
    Many inverters cannot tolerate that connection and either won't work, or will burn out.
    Just a thought.
    Wayne
  • System2
    System2 Posts: 6,290 admin
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    Re: Inverter problems

    It looks like I'm stuck with a bum inverter. After connecting a smaller 400w inverter to my batteries, it works fine. The tech help I got from the manufacturer claims there are no customer serviceable parts for it and unless it's under warranty, must be replaced. If I open the case to check any internal fuses, I'm on my own. :-( Only came with a 90 day warranty so I'll replace it with hopefully something comparable to what Brock got on Ebay. I'll limp along for now on the 400w inverter. I just don't like using it because it draws just over 1 full amp in idle. The big 2000w inverter only had a .02 amp draw in idle, I guess cause the cooling fans run constantly on the small one and the large one never needed it's fans running cause it never got hot. Yet another lesson learned the hard way. :-P
  • System2
    System2 Posts: 6,290 admin
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    Re: Inverter problems

    Thanks Brock for the idea. I picked up a brand new 1000/2000 watt Xantrex inverter for only $49 on Ebay. Smaller than what I had but still more than I need. Also a fraction of what I paid for my bogus inverter. I guess the "hiccup" in the "giddy" up is over. Thanks again! :-D
  • System2
    System2 Posts: 6,290 admin
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    Re: Inverter problems

    I just got my Xantrex inverter today to replace the "Chicago Electric" one I have that bummed out on me. I'm wondering if maybe I didn't wire the old inverter correctly, and that's why it malfunctioned on me. The instructions had me wire the ground directly to the negative terminal if installed outside a vehicle, which I did. Would it be safe and/or advisable to wire the new inverter grounding it to say, a copper pipe close by? I'd rather not go through this again in six months when or if the Xantrex inverter follows the same path as the cheaper "Chicago Electric" one did. Once I swap inverters you can be sure I'm going to pop open the bum inverter and do some snooping. Could this be a simple grounding issue?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,479 admin
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    Re: Inverter problems

    Probably not a failure due to grounding...

    The recommendation to ground the negative battery terminal just probably means that the case of the inverter is also at negative ground. This is generally done with any metal cased electrical appliance... The case is EITHER grounded (so that it does not assume a hazardous voltage if there is an internal short to the case) or the case is Double Insulated (per UL/NTRL requirements).

    Grounding per the instructions can also reduce radio frequency interference and improve static shock resistance (help prevent hiccups if somebody zaps the case in dry weather).

    And, generally, the inexpensive inverters will not work correctly (or at all), if both the negative battery terminal and one of the output terminals are both grounded at the same time (leave the output wires floating, don't do a bonded/grounded neutral like in normal home wiring--unless specifically allowed per the owner's manual).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset