7 Avionics: December 2011 Archives
I fabricated several 26AWG fusible links for the sense wires connected to the starter contactor and alternator shunt. Here's the one for the starter contactor.
This attaches to the right post on the starter contactor so that the VP-X knows when the starter is engaged. You can see the two additional fusible links below the starter contactor. These connect to the shunt.
Here's where these fusible links attach to the shunt. Before connecting these wires to the shunt, I attached the battery charger to the alternator side of the shunt to determine the correct orientation. Attaching the two sense wires to the wrong sides of the shunt would result in a negative current indication from the alternator. If I didn't determine the correct orientation now and got it backward, it would require reversing the sense wires at the EMS end which would be challenging once for the forward fuselage skin is riveted on.
This attaches to the right post on the starter contactor so that the VP-X knows when the starter is engaged. You can see the two additional fusible links below the starter contactor. These connect to the shunt.
Here's where these fusible links attach to the shunt. Before connecting these wires to the shunt, I attached the battery charger to the alternator side of the shunt to determine the correct orientation. Attaching the two sense wires to the wrong sides of the shunt would result in a negative current indication from the alternator. If I didn't determine the correct orientation now and got it backward, it would require reversing the sense wires at the EMS end which would be challenging once for the forward fuselage skin is riveted on.
I finished up the fuel flow sensor wiring run by crimping knife connectors on the wires from the EMS and attaching them to the wires from the FT-60 (red cube). I covered each of the knife connectors and the whole bundle of connectors with some heat shrink tubing and secured the wires with some Tefzel zip-ties.
The bundle of ignition, EGT and CHT wires running aft from the #4 cylinder weren't well supported. I riveted a K2000-3 nutplate to the side baffle and used a two-wire adel clamp to secure the bundle to the baffles. This prevents these wires from flexing down and contacting the #4 exhaust pipe (or flexing up and contacting the baffles under negative G conditions). Other than hooking up the starter wire just before first engine start and the coax wires to the electronic ignition coils, I believe all of the firewall forward wiring is complete. Other than final hookups of wing and empennage components (lights, roll servo, OAT probe, etc.), I believe all of the firewall aft wiring is complete as well.
The bundle of ignition, EGT and CHT wires running aft from the #4 cylinder weren't well supported. I riveted a K2000-3 nutplate to the side baffle and used a two-wire adel clamp to secure the bundle to the baffles. This prevents these wires from flexing down and contacting the #4 exhaust pipe (or flexing up and contacting the baffles under negative G conditions). Other than hooking up the starter wire just before first engine start and the coax wires to the electronic ignition coils, I believe all of the firewall forward wiring is complete. Other than final hookups of wing and empennage components (lights, roll servo, OAT probe, etc.), I believe all of the firewall aft wiring is complete as well.
