Success and failure today in a test run in the driveway. Nice clear sunny spring day.
I had spring fever so I dewinterized last night. Rinsed and filled fresh water system. It got down to 45F overnight and I'm assuming water started at that ambient temp.
Batteries were in 14.5V absorption by mid morning. All seemed well, but the wires got quite hot where they terminate at the element. This was with <10A current from the panels, well below the 300 watt rating. I confirmed that the element was not drawing from the battery.
I noticed the warm wires during bench testing, too. Wires feel progressively cooler the further from the element. The 8 gauge wiring I put in for supplying the current did not get warm. The heat shrinking around where the wiring terminates at the element started giving off smoke. I kept an eye on it and after 15 min or so it stopped smoking. What was once rubbery is now brittle.
I saw a max of 21A from the panels. I didn't have the laptop running at this point to see what the SCC said the diversion current was. I'm kicking myself for not putting my clamp meter on the wire at the element, but my hunch is around 19A. By early evening the water was hot! I measured 117F out of the kitchen tap.
But unfortunately the wiring looks cooked and I don't really trust it now. It needs some kind of high temperature heat shrink reapplied first. I just broke away the brittle stuff that was formerly the heat shrink and this is what is beneath it.
