Alternative Energy Forums

I am installing additional old Arco panels on a mission house in Central America.

I was perplexed by an extra terminal in the junction box. These terminals were daisy chained together with blue wires. Black and red were used for the positive and negative. I left the blue wire terminal unwired in my installation, and wonder if that was a mistake.

Here is a photo of the terminal box:


Anyone know what the blue wire terminal is for? Thanks!

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I found that on one of the panels the blue wire had been connected to the negative side of the diode. This is from an array of 27 panels on the previous installation. Almost every other panel had the blue wire attached to an unmarked terminal.

skoon