TRAP: Solar – Bad Professional Connections

Last month I was contracted to do some work for a local solar company. Part of that work was to salvage parts from old solar installation equipemtn that had been removed. Residential customers had hired this solar company to repair or replace their existing solar systems. The equipment I was salvaging was the stuff that had been removed and replaced with new equipment.

Yes, inside the old equipment had perfectly good bits and pieces that could be used to repair other equipment or sold as “used” for discounted prices. And yes, I love to do salvage work…it is fun to rescue perfectly good equipment pieces vs seeing them put into a scrap pile.

So I was tearing this stuff apart and found this shunt; the shunt was perfectly fine from all appearances, but it would be tested later to ensure that all was fine. But it wasn’t the shunt that caught my attention…it was the negative wire attached to the bus bar that was attached to the shunt. Do you see a problem with the connection? Here, let me give you another view…

Even if you are not an electrician or a professional solar installer you can see the problem. It is a horrible connection. I would estimate that only about 75% of the diameter of the wire is actually in the bus bar hole and even then it is only hanging on at the very end. So only about 10% of the original wire is actually connected to the busbar.

And no, that didn’t happen when I was removing the shunt.

Now, I will say that the screw was tight enough and was holding the wire in place, but that isn’t the point. There are two points;

1) The wire was only hanging on by about the last 1/8th of an inch…the very tip of the wire. It should have been fully inserted the entire width of the bus bar.

2) Only about 75% of the diameter of the wire was actually in the bus bar hole. In this case the wire was 6AWG stranded wire. Based on 6AWG the wire should be able to carry 70amps of current, properly installed. Well, since only about 75% of the wire’s diameter was actually making contact, it was the equivalent of about 10AWG stranded wire. And that means it was only capable of carrying about 30amps of current…had the wire been fully inserted. And since it wasn’t properly/fully inserted who knows for sure how much current the wire was actually capable of safely carrying.

See the problem with that?

Bottom line…

  • If you are doing the work yourself…do high-quality professional work. Don’t get in a rush, do it right, be proud of your install.
  • If you are having a system installed, ask to see inside the “magic boxes” and look them over yourself. You can see if the connections and work looks right and professional. If the installer gets upset or won’t take the time to show you what they are doing…well, that is serious reason for concern! It is your money…you have the right to inspect it all.
  • If you are buying a house that has a solar system, have it inspected by a local quality solar system installation company or a licensed electrician that is familiar with solar. It will be worth the fee.

These kinds of situations occur all of the time…there is some very shoddy workmanship out there by unprofessional and/or ignorant folks. Don’t you do it and don’t tolerate it from others.

Why? Duh, you could find yourself at the losing end of a house fire.

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