By Thad Yukna, Marine Systems Student Ambassador
Now that the foundation is complete, “we start at the source.” A mantra from Nels, our lead instructor, and normally for troubleshooting, in this case it refers to where our installation begins. Each team received a pair of batteries for their sim (simulation board), the smaller to serve as our “start” battery and the larger one our “house” battery.
Once we had batteries, it was time to start wiring but first we had to pass the pull test. Each connector in a marine system must be able to withstand a pulling force that varies according to the size and type of the conductor.
Everyone in the class took turns crimping on connectors and then subjecting them to a weighted pull to be sure we could meet the standards.
We also had a chance to play with electricity to get a better picture of the importance of tight, complete connections. The charring occurred as a load upped the amperage flowing through the loose wire and the arcing began heating things up. It wouldn’t take much for that to turn into a burning boat.
Once we had that down, we started installing parts onto our simulators. The tape allowed us to measure and mark the board without leaving permanent marks. First up are the battery switches and the main fuse blocks that will protect the board.
One benefit of the new consolidated campus in Newport is occasionally being able to slip over to Restoration Hall and soak up the atmosphere. The morning light always does some magical things with the old bricks and varnish.
Back to Systems, we tied all of the hardware together with the appropriate wiring. The black lines are red wires wrapped in sheathing in accordance with ABYC standards based on the distance between overcurrent protection and the power source, in this case the batteries.
Additionally we wired up the engine instrument panel and pinned up a Deutch plug (lower left) wire harness that eventually be connected to a diesel engine which we will start from the sim.
It looks a little crazy on the back but it all works great. At least on the test set, we’ll see how it goes at the end of the course once the engine is hooked up!
We are also challenged to solve some basic design problems. The objective here was to use relays to set up the bilge pump circuit such that the higher float switch turned the pump on and the lower float switch turned it off. My initial design used two relays, but we finally whittled it down to just one.
We also practiced paralleling and series-ing 12 volt batteries to meet different systems power requirements. This set up is 24 volts and over 3000 amp hours. That is a LOT of whallop.
We wrapped up this section with a few more DC components like the bilge blower fan set, bilge pumps, float switches, a high water alarm, and a 12v light along with the electrical panel itself. Next up we step up to Alternating Current and more toys on the board.
Thanks for looking! Until next time,