Solar 1.1 – Part 3

Once the feet had set for 72 hours, it was time to reassemble the roof. We placed the panels in their designated locations and attached the wingnuts. Out of an abundance of caution, we installed an inline 10amp fuse on each panel. Sending our lightest team member back on the roof, we laid out the bulk marine 10AWG duplex wire and mapped the paths to be as efficient as possible.

To secure the wires from moving, we used UV resistant zip ties attached to zip tie mounts/pads. As these would be load bearing, we replaced the pads’ tape with VHB tape. These too were sealed with Sikaflex 221. Once we had the wire lengths approximated, it was a matter of stripping the ends with wire cutters and attaching the MC4 connectors. About MC4 connectors, they can be crimped, carefully, with needle nose pliers or the wire cutters. A proper crimping tool can make the process easier and faster. MC4 connectors are also designed to be tightened only once. Removing them, such as if you accidentally reverse polarity usually damages internal components beyond reuse. Double-check your work before securing the connectors. I have gotten pretty adapt at hand tightening the connectors but the proper tool makes a difference and provide piece of mind that the connectors are secure.

Once everything was wired, we reset the circuit breaker to supply power the charge controller. Once it came online, we turned the solar panel disconnect switch to the on position and confirmed that the panels were delivering a charge. In the end we went inside and disabled the battery charger/converter. This ensured that the only power being delivered to the 12V system was from the solar and batteries. We also plugged in our external panels to check but as the batteries were already full and there was ample sun, not much power was actually used the system. Eventually, the next few drive days confirmed everything was working as planned. We started with charge controller’s default settings but later switched to AM Solar’s suggested charging settings.

For the tilt bars, we purchased aluminum flat bars, cut them down to 1 foot lengths and drilled 1/4″ holes on either end. The AM Solar wingnut still attaches to the end closest to the panels and we added additional bolts and wing nuts to secure the tilt arm to the feet.