Electrical System

Question 1

PMG On/Off N2%

Answer 1

On - 50%

Off - 20%

Question 2

PMG Output

Answer 2

3 x 28VDC

Question 3

Battery Life (inflight)

Answer 3

5-10 min

Question 4

Battery Voltage/Amps

Answer 4

24.5 V

15 Amp

Question 5

Normal Battery Voltage

Answer 5

24V

Question 6

Bad Battery Voltage Indication

Answer 6

18 V

Question 7

Battery On Limit on Deck

Answer 7

2 min

Question 8

AC Generators

Answer 8

Powered by AMAD Power Transmission Shaft

Either generator capable of powering entire aircraft load

Question 9

PMG (Permanent Magnetic Generator)

Answer 9

Works independently from Generator

3x28VDC power windings

• 2 provide power to their respective FCC Channel
• 1 routed to back up the DC Ess Bus

Question 10

Prior to Start Battery Powers

Answer 10

Maintenance Bus and APU

Question 11

Gen Tie Logic

Answer 11

Isolates a Bus or Gen that is not performing properly

Allows one reset and if fault still exists, logic will isolate the problem

Question 12

Requirements for Gen Tie Logic to work

Answer 12

Battery Switch On
Parking Brake Set
Gen Tie Switch not in Reset

Question 13

Get Tie Light

Answer 13

On Ground
- Parking Brake Handle not set after first engine start

In Flight
- 115 AC Busses isolated for either bus or gen fault

Question 14

T/Rs (Transformer/Rectifiers)

Answer 14

2 T/R’s convert 115 VAC from busses into 28VDC

Capable of entire load

Question 15

Single T/R Failure

Answer 15

No cockpit indications

Question 16

Dual T/R Failure

Answer 16

Loss of HUD

Bleed Air - to include cockpit pressure and OBOGS

Question 17

FCC Electrical Redundancy

Answer 17

1) PMG
2) Ess Buss
a) R T/R
b) L T/R
c) R PMG
d) L PMG
e) Battery

Question 18

Circuit Breakers

Answer 18

Left

• FCC 1
• FCC 2
• Launch Bar

Right

• FCC 3
• FCC 4
• Hook
• Landing Gear

Question 19

Dual Gen Failure

Answer 19

Loss of all displays
Bleed Air
Radalt
Nav Instruments
Select Jett
Hyd Press Indicator
Cabin Press
OBOGS
Normal Gear Ext
Anti Skid

EFD Shows RPM and EGT only

Comm 1 Maintains last Freq

Batt Gauge shows 28V with no Batt SW Caution

Question 20

DUAL GEN & PMG Failure

Answer 20

Same indications as Dual Gen but Batt Gauge reads = 24V

Question 21

Batt Voltage where FCC’s Lose Power

Answer 21

18V

Question 22

GEN On/Off N2%

Answer 22

On - 60%

Off - 52%