Chapter 2.1.4 - Engine Electrical System

Question 1

What does the alternator power?

Answer 1

ignitors, EDECU, and Ng signal to the instruments

Question 2

EDECU inputs

Answer 2

ENG SPD TRIM
CONTGCY PWR
ENG OVERSPEED TEST A/B

Question 3

EDECU Operation

Answer 3

-Np Governing
-Np Overspeed Protection - 120%
-Np Overspeed Test - References Np from 120% to 96%
-Ng Decay Relight - Specified Ng deceleration will turn on ignitors for 5 seconds. Disabled <62% Ng
-Manual C-Power - TGT increase to 903, limits fuel flow at 891+-10
-Auto C-Power - OEI conditions when torque of one engine <50%. 866 -> 891+-10
-Dual C-Power - 891+_10, Np droops below 96%, Greater than 3% droop in Np and reference, greater than 5% per second Np droop
-Hot start prevention - TGT exceeds 900 with Ng<60 and Np<50. Restored 300*C or 25 seconds
-Edecu lockout - Torque motor servo disabled
-Fault diagnostics - supressed by overspped test, cleared TGT > 425 with PCL in Idle or Fly
-TDI - initiates Np acceleration early using anticipator signals from TDI Nr sensor on left accessory mod
-Auto ignition - when Np overspeed or test, ignition sequence is initiated for 5 seconds
-Signals - TGT, Np, Torque to cockpit
-TGT limiting - 866+-10 MRP 878
-Engine Load sharing - torque matches
-Speed Trim - 96-101% Np

Question 4

CEDECU code

Answer 4

35+-2.9%

Question 5

Ignition System

Answer 5

2 ignitor plugs
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