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Solis melted connector

  • 13-05-2023 11:24pm
    Registered Users Posts: 9

    long story but did a semi self install of my solar system solis rhi-6k-48es-5g inverter and 18 x 360w panels.

    got it up and running about 2 weeks ago then today went into plant room where inverter is and got burning smell the mc4 connector going into the dc1 negative had melted and blown out.

    Any ideas what would have caused this? Dodgy crimp on mc4 maybe?

    the connection on the inverter is completely goosed, anybody know can I replace them? Or what are my chances of getting inverter fixed under warranty?


  • Moderators, Home & Garden Moderators Posts: 5,893 Mod ✭✭✭✭graememk

    Hard to tell the cause now, but I've seen a mc4 not properly plugged in heat up enough to melt the plastic and deform.

    I doubt you can get a warranty replacement...

    I did see someone posted a photo of the inside of the solis recently but that should be fixable if you feel comfortable taking things apart.

  • Registered Users Posts: 9 dave_dth

    Thanks, I ll see if I can find a service manual for it.

  • Registered Users Posts: 6,800 ✭✭✭10-10-20

    Who made or crimped the cables and what gauge (mm2) are they? If you self-crimped them, what tool was used?

    You said "had melted and blown out.", how do you mean blown out?

    Yesterday was warm and sunny here, I presume that the local conditions were relatively similar, so you might have been over 6kW in generation? Is the load split evenly between both MPPT inputs and is the cabling known to be good? If possible tell us where else you have MC4 connectors on the same string or show us a diagram of the layout of both strings?

    BTW, in my opinion those stringy soots which are attached to the inverter typically indicate that a flame was present for a time as smoke from heat alone would not create strings. The cables and connectors should be made from self extinguishing plastics, so that would have limited the spread and duration of the flame. For that reason it's always recommended that the mounting/backing to high energy systems like this have flame-resistant covers rather than a wood finish.

  • Registered Users Posts: 122 ✭✭fael

    There are also a few videos on Youtube where they repair Solis inverters. Might not be the exact model but the basics are the same. You'll get a feel for how involved it would be.

  • Registered Users Posts: 1,726 ✭✭✭tnegun

    It must have been a bad crimp or the MC4 connector wasn't assembled properly as in the crimped piece pushed all the way in. I bought some secondhand panels and one of the MC4 connectors was deformed and showed obvious heat damage. I don't know if the heat caused it but when I went to disassemble the pin wasn't pushed home regardless heat in a connector is the result of a bad/poor connection.

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  • Registered Users Posts: 6,800 ✭✭✭10-10-20

    This is my concern and sorry to the OP if I came on too strong with the questions, but at the end of the day we, as a subset of users need to understand these issues and take onboard any safety considerations or best-practices that we can.

  • Registered Users Posts: 1,421 ✭✭✭Big Lar

    I would assume something like the connector below would replace what you have, may not be the exact one so have a look around the website, and it seems like a simple fix