Help! Did I ruin the panel?

[Darin O.]

I though I would put C4 connectors at the controller on the wire coming from the panels so I could disconnect them easier when needed.

I accidentally touched the positive from the panels to the negative from the panels. There was a small spark. Now I’ve got no power coming from the panels (Two 100 watt Renogy panels)

Did I fry the panels? Did I fry something inside those little black boxes on the back of the panels? Is this fixable without buying new panels?

I feel like an idiot

 

[mopat]

Panels probably fine, diodes (inside those little black boxes) probably not.

They're 10SQ050 diodes; check eBay, they're about 0.20 each.

 

[Hedges]

Shorting a panel shouldn't damage anything, not even the diodes.
Check voltage from panel with a meter. If zero, open circuit somewhere. (or shorted, but not likely)

 

[Thames014]

Is there a fuse on the wires coming from the Panels? Have you tested the voltage at the closest point to the panels?

 

[MrNatural22]

Shorting a panel shouldn't damage anything, not even the diodes.
Check voltage from panel with a meter. If zero, open circuit somewhere. (or shorted, but not likely)

I agree. Shouldn't be any damage.

 

[Darin O.]

Tested everything with a meter. You were right, no damage at panels. It was a bad connection at one of the MC4 connectors I had installed on the negative wire coming from the panel. I really appreciate all the responses. I bought and learned to use a multi-meter in this process.

 

[Hedges]

I usually buy MC cables, cut them in half to make pigtails for connections to other things. I don't have a specialized MC crimper yet.
I might make my own cables for the next phase of my project because I'm seeing different prices now and ready-made would cost twice as much.

I've also bought pre-made cables for larger sizes (4/0) that didn't fit my hydraulic crimper, but did my own 2/0.
There are some tradeoffs and choices to do a decent job with what we have available.

If you get an MC4 wrench that may make them easy enough to un-connect.
My earlier panels from mid 2000's had MC3, just a rubber boot and push/pull. A clamshell was available to meet the requirement of a tool to disconnect. I'm considering using those for easy swapping of connections (rearrange some panels to feed something different.) I would put them inside a switch with interlock on the door to ensure they aren't unmated under load.

 

[pjones]

Be careful with the MC4 connectors, there are lots of poor quality ones out there, and the connections may be loose if you didn't crimp it well.

 

[Darin O.]

Thanks again everyone for your responses!