Electrical

Mark's Mustang II Project Pages

Electrical System

Electrical System for Mustang II - N515MD

The panel is an all electric panel with no vacuum system. Future upgrades are to add a backup alternator to the vacuum pump pad for redundancy. The system includes the standard 6 instruments and a GI106 GS/LOC/VOR indicator driven by the Garmin GNS430. A GTX327 Provides transponder functions. Each instrument is lighted with a Nulite and is dimmable via a voltage regulator provided by B&C Specialty products.

Engine instrumentation is provided by a LCD display that reads engine info via an array of sensors. This was custom built by me. The computer is a 68hc11/3Mhz and a 300Mhz PC to process the graphics.

The electrical system is divided up into two busses. In the event of an alternator failure the primary bus is powered down via the master switch and the plane is operated from the essential bus with a total loading of approximately 8amps. The battery is a Concorde 25Amp/Hour RG battery. The essential bus is isolated from the primary bus via a diode.

I used the ‘Aeroelectric Connection’ documentation to design the electrical system (www.aeroelectric.com).

Essential Bus

	Function	Fuse Type		Function	Fuse Type
1	Instrument Light Dimmer	3A	6	Garmin GNS430 Power 2	10A
2	Trim Tab	3A	7	Starter	7A
3	Turn Coordinator	3A	8	Main Fuel Pump	3A
4	Attitude Indicator	3A	9	Cyclops Engine Monitor	5A
5	Garmin GNS430 Power 1	5A	10	Spare

Primary Bus

	Function	Fuse Type		Function	Fuse Type
1	Garmin GTX327	3A	6	Aux Fuel Pump	3A
2	Intercom	3A	7	Map Light & Aux Power	3A
3	Alternator Field	3A	8	Position Lights	5A
4	Avionics Fan & Low Volts	3A	9	Strobes	10A
5	Pitot Heat	15A	10	Directional Gyro	3A

Notes

· Dimmer connected to all instrument lights
Dimming for Garmin GNS430 and Garmin GTX327 via CDS cell.
Dimmer is capable of sourcing 3A of power for all lights.
Logic dimming connected to intercom and trim tab indicator through the instrument light switch. When lights are switched on these two instruments will dim.

· Essential Bus voltage wire is direct from the battery + terminal to the switch on the panel. This wire is protected by a 15A fuse located near the battery in an inline blade fuse connector.

· Ground wire is 4AWG and runs to a single ground point on the firewall. A 48 fast-on tab bus is located here for all systems ground.

· Power wire is 2AWG and runs directly from the battery to the starter. Primary bus is powered from this point by a 10AWG wire.

· The intercom is grounded at the radio ground (essentially at the firewall single point ground) to eliminate ground loop induced noise.

· Ms3116E8-4S used for Attitude, DG, and T&B. Pin out is as follows:

* A *C

* B *D Looking into the pins at the back of the instrument

Switches on Panel

(Starting on left)