Solar Rescue Mission
Stan-the-Hermit Needs Help
I knew there was trouble as soon as I saw the Caller-ID. Stan’s system has been under performing, partly because he doesn’t have a decent battery and partly because half of his panels never got connected. Well, more than that, it turns out.
I loaded up my big spool of solar cable and a fistful of connectors and adapters and headed for Canoe Creek. You can’t get to his cabin in a straight line. No, you have what seems like miles of hill and dale and switchbacks. Florida is reputedly flat, but not along Canoe Creek. I know to take it easy and asked myself when was the last time the pickemup got new shocks.
I finally arrived and was delighted to see he was wearing pants. That was probably more in deference to the cool weather than knowing company was coming. If the weather is warm and there is nobody to complain about your wandering around in your shorts, then why not?
One thing I knew I wanted to do from the beginning is put the panels in series pairs to get a little more voltage to the MPPT controllers than just hanging them all in parallel. His is a 24v system so you can get away with it, but I like my way better and he’ll have less loss than trying to run 40 amps through a 30 amp wire.
Remarkably, he got away with just that sort of stuff for years on his old 12v system, which still works.
Stan has more ladders than anybody else I know, so there was one handy to go up for a better look. Just a word of advice here about old fiberglass ladders that have been left out in the weather. They sprout little glass fibers that will cause you to itch like mad if your bare arms come in contact.
First thing I noted was the panels were dirty. OK, mine are, too, so don’t count on 100% of rating. I cut the cable ties loose so I could see what was going on. Two panels were in parallel on one downline and 3 more were on another. Technically, he was running too much power into that 60 amp charge controller, but not really. There just wasn’t that much power. Stan was telling me that at high noon on a clear day he was getting over 500 watts on the meter. These are 305 watt panels. Five of ’em. Dirty or not, there should be more power.
I paid attention as I dismantled stuff. First of all, I cut the switch to the charge controller. That’s what it is there for. Pulling MC4 connectors under load can draw an arc and either burn up the connector or even burn you. So, for a few minutes, I was up and down the ladder, switching off and on and reading meters. Stan could have worked the switches and meters, but I wanted to see for myself what was going on. Know what I mean?
About the right amount of power was coming in on the one downline and not a thing was coming down the other. One of the MC4 connectors didn’t look quite right and it was indeed bad. Maybe it was corroded or maybe it was burnt.
“Well that’s one I got from you!” Stan declared. True. He got it out of my junk box. What happened after I took it out of service was beyond my control, yet the problem was MY fault! Stan must be related to my wife. They think alike.
I cut off the connector and put on a new one and he was back in business with 4 modules instead of two. That’s got to work better. I barely had enough time to get to Pensacola for something I wanted to do, so I told Stan to just copy those pairs 3 more times and he’d be done. I even drew a picture.
Moral to the story? Get everything out so you can see how it is connected. Check every connection. Don’t assume anything. If something seems wrong, maybe it is.
As for finishing up, Stan decided to go to the beach, instead. He still has my roll of cable.