Electrical System Part 2

A view of the back of the instrument panel. At 'A' is the Master Switch and with feeds for the ignition switch and the ammeter and voltmeter. The master switch is fed from the fused master terminals on the Hotbox. The EIS has a digital voltmeter but no ammeter and I like to have be able to monitor the health of the electrical system from the panel without having to push a button to change screens thus the redundant analog voltmeter. The alert function of the EIS will back up my scan. At 'B' is the Bat+ bus fed from the master switch. One circuit from here goes through a fuse and Avionics Master switch on the distribution panel 'C' then on to the Bat+ bus on the panel at 'D'. The distribution panel also has fused and switched circuits for Strobes (fed by a seperate circuit from the Hotbox), Nav Lights, Landing Lights, the Fuel Pump, and a spare.

Another view. At 'A' are the annunciators for the EIS and the Fuel Pump. Next time the panel's out of the plane I want to include a light to indicate that the landing light is on. It's obvious at night, of course, but not in the daytime. Just below them at 'B' is the remote for the ELT. C' is the clock. This is on an independent fused circuit directly off the battery so it's on all the time.

Wiring and plumbing completed. Color coded pin connectors 'A' are installed on each circuit. I opted for individual connectors rather than one or two multi-connectors for ease of circuit isolation in the event of the need to trouble-shoot the system.

55W Halogen driving light / landing light. At 'A' is the OAT sensor for the EIS.

Wire runs in the fuselage and wings should be twisted pairs. This stiffens the pair, keeps them neater, makes them easier to pull through tubing etc. It also helps keep down RF interference I'm told. An easy way to twist the wires is fasten down one end, chuck the other ends in a drill, stand back, pull out the slack, and twist and shout. This can even be done with wires that are already inside a tube as seen here. Twisting shortens the length of the pair somewhat, so allow a little extra. And it's so much fun (yeah, I need a life...) don't overdo it and put a lot of stress on the conductors. Also, be ready to control the wires tendency to untwist somewhat when you unchuck em. If you don't, the snarl will look like my fishing reel did when I was a kid.....

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