Moisture in Inverter

I've got an SMA SB5000TL-22 inverter in a client's basement that has moisture beading up behind the glass window in front of the LCD screen. My techs plugged the conduit going to the outside, so there's no way moisture is getting in that way. The inverter was replaced once, on the assumption that the seal might be bad on the black plastic face plate, but the problem also occurs on the new inverter. My only idea is opening the spare conduit inlets on the bottom of the inverter and or putting desiccant packs in. Alternatively, I may just recommend the customer purchase a dehumidifier. Anybody else got any better ideas? SMA was no help. 


  • Dave AngeliniDave Angelini Solar Expert Posts: 6,186 ✭✭✭✭✭
    Where is the location of the home? Basements can be bad for moisture. I once ran a fan with a duct from the warm garage down to bring warm car engine heat in.  Buy the extended warranty.....
    "we go where power lines don't" Sierra Nevada mountain area
    E-mail [email protected]

  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    The condensation of moisture on the window is a sign of two things:
    1. The air in the basement is cooler than the air inside the working inverter. (Not at all surprising).
    2. There is liquid water somewhere inside the inverter which is keeping the inside humidity high even as the air heats up.

    One possible source of water is condensation when the inverter shut down for the night and cools off. But that requires a source of warmer humid air connected to the inside of the inverter.
    Another possible source is condensate water dripping down from a connected conduit.

    If it is not either of those, you have an interesting problem to troubleshoot!

    I doubt that the inverter housing is designed to be air and moisture tight. At best it is designed to shed rain water when located outdoors. But there should be vent/drain in the bottom somewhere.

    Just opening up the enclosure for better air circulation (since it is in a protected area) might do the trick, but could have both warranty and safety implications.

    SMA SB 3000, old BP panels.
  • waynefromnscanadawaynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    My uncle, who lived on the grid, once had an interesting moisture problem in his entrance panel.
    Connector terminals for incoming cables corroded and ended up with only one side of his split 120 / 240 panel receiving power. Ended up the incoming cable where it connected to the grid wires on top of the mast were not covered, resulting in water wicking down the twisted wires inside the insulation of one of the hot cables like a mini pipeline, and dripping into the inside of the entrance panel.
  • zycaozycao Registered Users Posts: 2
    It is the design deficits. But the company will not admit this can damage the inverter. It is because that the hot air gets into the tube, at the night, when the temperature goes down, the the water comes out from the air, that is why you see the moisture. They didn’t use water prevent tube.They should freely fix that. 
  • zycaozycao Registered Users Posts: 2
    I am still arguing with the company, this should get attention. Otherwise, you are throughout your money into the rive without hearing anything.
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