pc12.du

The PC12 Display Unit (DU) is essentially a liquid crystal display installed in a rectangular box which houses the solid-state circuitry that processes the signals supplied by the acquisition unit. The TRQ, ITT, NG, FUEL QTY and ENG OIL gauges are all independent graphic-type LCD gauges. Propeller Rotation speed (NP), Fuel system and other readings are in Independent Digital LCD readouts.

28vdc power is supplied to the EIS as shown in the table below. This configuration prevents a total loss of electrical power to the EIS in the event of
a single DC bus failure.

Bus Bar | Aircraft | Circuit Breaker | Amp
Battery Bus | 112 and After 111 and Earlier II | EIS 1 EIS DU 1 EIS ACU 1 | 5A 5A 5A
Gen 1 BUS | 112 and After 111 and Earlier II | EIS 2 EIS DU 2 EIS ACU 2 | 5A 5A 5A

| 1. Menu Switch 2. Secondary ITT Readout 3. Secondary Torque Pressure Readout 6. EIS Test switch

Built in Test-Equipment or (BITE) continuously monitor the EIS for system failures. Should a failure occur on aircraft 112 and later, torque pressure and interturbine temperature data can be supplied by the secondary circuit by press the MENU1 button located in the lower center of the DU. When this menu is selected, the digital readout of OAT and ENDUR are then replaced with ITT2 and TRQ3 readouts respectively and the primary TRQ and ITT displays go blank.

The system may be tested before or inflight by using the EIS Test6 switch. This will test all readouts and LCD displays for 6 seconds then return to normal.

Also located on the DU between the MENU and the TEST button is the FUEL RESET4 button. Pressing this button will reset the USED5 fuel counter back to 0. This would be the fuel amount used during that leg of the flight. By using this, you can at each leg or stop, record the amount of fuel used for that leg or stop and then zero out and record the amount for the next leg or stop.

| 4. Fuel Reset button 5. Fuel Used Readout