SEE B747 PANELS HERE

B747 ELECTIC QUESTION EXAMPLE

B747 ELECTRIC QUESTION EXAMPLE

1. AIRCRAFT BATTERY AMPERAGE AND VOLTAGE? 24V, 34A

2. TR AMPERE? 75A

3. EXT POWER TR RATE? 20A

4. WHAT’S THE AMPERE OF BAT CHARGER? 40A

5. IF OPEN PHASE DETECTED WHICH ONE TRIPS? BTB TRIP

6. TR INPUTS? 115VAC, 3PHASE

7. MAX ALLOWED CSD TEMP RISE? 15 DEG

8. WHERE’S GND SERVICE RELAY? P14

9. WHERE’S BATT THERMOSTAT? UP IN ONE OF CELLS

10. HOW CAN CSD CONNECT? ON GND WITH ENG S/D

11. CSD OIL TEMP SHOWS? OIL LEAVING CSD

12. ENG S/D WHICH RELAY TRIP? GCB

13. WHICH CONDITION FOR FUELING? STBY SW MUST OFF, BATT ON

14. WHICH UNIT CONTROL SSB? BOTH CAN OPEN BUT CLOSING BY BPCU2 ONLY

15. APU MECH FAULTS WHAT HAPPEN? APB TRIP

16. APU ELEC FAILURE? GCR TRIP

17. HOW CAN CONNECT BTB? MAN OR AUTO

18. BAT BOOSTER OUTPUT? 23V

19. WHERE PMG AC VOLTAGE CONVERTED TO DC? INSIDE GEN OR GCU?

20. FOR MEASURING REACTIVE POWER?CURRENT FROM PHASE B, VOLT FROM PHASE A,C

21. WHEN BEARING FAILURE? DISCONNECT CSD

22. HOW CAN POWER THE GND HAND BUS? GND ONLY, EXT PWR CONNECTED

23. EXT POWER AND APU ARE CONNECTED WHAT’S PRIORITY? EXT (FOR HAND BUS)

24. SSB GREEN LIT IS ON MEANS? SSB OPEN

25. NORM SOURCE OF DC BUS? TR

26. RADIO BUS SW AND MASTER RADIO SW LOCATION? P5

27. WHERE ARE DC ISO SW’S? P4

28. NORM SOURCE OF AC ESS? AC4

29. CSD IS A? HYDROMECHANICAL

30. APU BAT CHARGER LOCATION? E8 IN AFT

31. ELCU CONTROL SWITCH SYS? GALLY

32. IF BOTH EXT POWER OR BOTH APU CONNECTED? SSB TRIP

33. OUTPUT POWER OF ENG’S? 60KVA

34. OUTPUT POWER OF APU? 90KVA

35. WHICH BUS POWERS F/O RADIO BUS? AC2

36. DIFF OF APU AND ENG GEN’S? APU HASN’T CSD

37. CSD SPEED? 8000RPM

38. WHICH ONE CONTROLS APU RPM? ETC

39. WHAT KIND OF WIRE USED IN A/C? ALUMINUM

40. CSD HAS CAPABILITY OF? UNDERDRIVE(NO OVERDRIVE)

41. HOW CAN READ GEN FAULTS? PUSH READ P/B ON ANN PNL

42. HOW ERASE FAULTS? READ AND ERASE AT THE SAME TIME

43. DC STBY NORM POWERED BY? DC ESS

44. WHICH BAT NEED FOR APU STARTING? BOTH BAT

45. MAN ON POS OF INV? FOR TEST

46. BAT BOOSTER USED FOR? VHF1, VOR1, G/S1

47. BAT BOOSTER LOCATION? UPPER EQUIP CENTER

48. INV LOCATION? UPPER EQUIP CENTER

49. BAT CHARGING MODES? PULSING, CONSTANT POTENCIAL, NORMAL

50. PULSING USED FOR? WHEN BAT IS FULLY CHARGED

51. FAULT IN SYNC BUS? LOAD LIT ON

52. GND HAND BUS CAN POWER BY? APU1 AND EXT1

53. WHEN BAT CHARGING HOT BAT BUS POWERED BY? BAT

54. TEMP FOR STOP BAT CHARGING? 58DEG

55. APU BAT CHARGER POWERED BY? GND SRVC BUS

56. IF CSD DISCONN WHICH ONE TRIP? GCB

B747 CHAPTER 49

49

1. APU HAS 4 STAGE COMP AND 2 STAGE TURB
2. START ALLOWED MAX 20000FT, PNEU FOR MAX 15000FT , ELEC HAS NO LIMIT
3. IN W/W REMOTE S/D PNL FOR S/D AND DISCH BOTTLE
4. FIRE S/D RELAY AND FAULT RELAY ARE IN P52(UNDER P4)
5. APU CONT RELAYS ARE IN P83 (AEC)
6. EXTING BOTTLE AND APU BAT ARE IN APU COMP
7. ELEC AND PNU CAN SUPP ABOVE 95%
8. INTERSTAGE VLV OPEN AT 95% (TO BLEED)
9. INLET DOOR POS:
                                    GND: FULLY OPEN
                                     FLT: 15 DEG
                                     OFF
10. APU COOLING S/O VLV ACTUATED BY CDP (7.5PSI) COZ S/D IF CLOGGED OR NOT 
      OPEN WHEN N> 95%
11. NO GEN COOL LIT ON IF FLOW LOSS IN GEN AND APB TRIP
12. A SURGE VLV USED TO SURGE EXTRA AIR DEPENDS ON DEMAND, CONT BY ETC 
     (ELEC CONT TURB), PNEU OP
13. APU DC FUEL PUMP OPERATES IF GND SRVC OFF (DC PUMP ON LIT )
14. APU FUEL S/O VLV IS ON AFT SPAR OF #2MAIN TANK
15. FUEL S/O VLV OPEN WINDING POWERED FROM HOT BUS
16. FUEL S/O VLV CAN OFF BY FIRE HANDLE AND MASTER SW
17. APU FUEL PUMP:
                                    DC: APU PUMP
                                    AC: AFT PUMP IN MAIN TANK2

18. APU BAT CHARGING CUT DURING START
19. MSW OFF SIMULATES FAULTS TO S/D
20. START IS LIM TO 60SEC AND 90SEC IN COLD SOCKS(BE 2 HR IN COLD AIR)
21. RESTART ALLOWED JUST 2 TIMES IN 1 HR AND 3 TIMES IN COLD SOCKS
22. FUEL SOLE VLV CUT AT 7%
23. IGN OFF AT 95%
24. STARTER CUT AT 50%
25. LOW OIL PRESS COZ AUTO S/D AFTER 10 SEC IF N>95%
26. HI OIL TEMP COZ S/D IMMEDIATELY
27. CIT SIG LOSS COZ S/D IF N< 95%
28. ETC IS IN APU COMP
29. A LOAD CONT VLV MODULATED BY ETC TO LOWER THE EGT
30. A METERING VLV OP BY TORQ MOTOR CONT BY ETC REGULATES FUEL DEP ON LOAD 31. SECONDARY NOZZLE SUPP WHEN DEMAND > 30%
32. HOUR METER ON AT 50%
33. BAT FEEDS 1000A MOMENTARILY IN START
34. APU ANTI ICE VLV POWERED FROM APU BAT, IT WILL OPEN BELOW 4°C
35. REMOTE S/D PNL IS IN R/H MAIN W/W
36. ETC IS IN APU COMPARTMENT
37. FCU CONT THE METERING VLV SEND FUEL TO FLOW DIVIDER

B747 CHAPTER 36

36

1. HI STAGE TAPPED FROM 15TH STAGE

2. HP VLV CLOSED IF PRESS>90 PSI AND LIT OFF

3. OPEN LIT ON IF HP OPEN MORE THAN 7 DEG

4. A RELIEF VLV OPEN AT 120 PSI IF HP FAILED

5. WHEN GND START : PYLON VLV AND START VLV OPEN, HI STAGE OFF, REVERS FLOW  

       VLV BYPASSED

6. CONT VLV DOWN STREAM OF PRECOOLER WILL OPEN AT 350 DEG F

7. A THERMAL FUSE MELT AT 650 DEG AND HP VLV CLOSE

8. O/H LIT WILL ON IF PYLON VLV CLOSE IN: FIRE HANDLE OP, 490 DEG

9. PYLON VLV HAS 2 SOL: FRO ROTARY SW, FOR GND START

10. APU ISO VLV: CONT BY 28VDC FROM BAT BUS, OP BY 115VAC

11. A HI STAGE CONT VLV CONT THE HP VLV ON R/H OF ENG (HP VLV IS L/H)

12. PRESS IND HAS 2 SYN FOR L/H AND R/H MANIFOLD TX

13. PRESS TX LOCATED UPSTREAM OF WING ISO VLV IN W/W

14. PRESS TX HAS 2 PORT WHICH ONE OF THEM VENT TO AMBIENT

15. 2 ISO VLV LOCATED IN AIR COND BAY AND APU ISO VLV IN L/H W/W

B747 CHAPTER 32

32

1.               L/G USE HYD1, 4 BUT IF NOT AVAIL ALTERNATE EXTENSION SYS WHICH IT IS AN ELEC ACTUATOR UNLOCK AND L/G EXT BY GRAVITY

2.               NOSE AND BODY (DOORS AND GEARS) AND STEERING USE HYD1

3.               WING USE HYD4

4.               DOORS CAN RELEASE BY A CABLE  OPERATED BY A HANDLE

5.               STEERING IS MAX 7 DEG BY PEDAL AND 70 DEG BY TILLER

6.               STEERING USE HYD1 IF L/G LEVER DOWN

7.               BODY GEAR TURN IN OPPOSITE DIRECTION OF NOSE

8.               MAIN GEAR MUST TILT 7 DEG BY A POSITIONING ACTUATOR AFTER LIFT UP

9.               4 AMBER TILT LIT  ON P4 WILL ON IF ANY GEAR NOT TILT

10.            A PRESS REDUCING VLV IN BODY W/W REDUCES PRESS TO 2000 PSI TO ALLOW GEAR UN-TILT IN GND

11.          WING GEAR HAS A MECH LOCK TO ENSURE TILT IN HYD FAIL

12.          L/G IND:

                     GEAR DOWN LIT (GREEN): WILL ON IF ALL GEARS DOWN/LOCK 

                     GEAR LIT (RED): WILL ON IF DISCREPANCY BETWEEN HANDLE

                            AND GEARS POS ALSO IN TRANSITION

                     DOOR OPEN LIT (RED): WILL ON IF ANY DOOR OPEN

13.            THERE ARE 2 L/G SELECTOR VLV IN BODY W/W:

                                                                   R/H: FOR WING GEARS

                                                                   L/H: FOR NOSE, BODY AND STEERING

14.            L/G LEVER POS:

                           UP: IT’S LOCKED BY A SOLE, CAN BE UP IF TILT AND STRAIGHT

                           OFF: HYD CUT

                           DOWN: GEAR SELECTOR VLV OPERATED

15.            ALT GEAR EXT SW:

                                      EXT: MUST 5 TO 10 SEC HELD THEN ARM FOR MORE THAN 90 
                                               SEC TO ENSURE POWER APPLIED

                                      ARM: SPRING LOADED TO ARM

                                      OFF

16.            ALT WING L/G DO NOT EXT IF DOOR OPEN < 40 DEG

17.            ALT NOSE EXT DRIVE UNIT IS IN PRESS AREA (MEC)

18.            2 LOGIC MODULE FOR L/G (PRIMARY AND ALTERNATE) IN MEC ARE NOT I/W EACH OTHER AND USE SEPARATE SENSORS

19.            PROX SW’S GO TO PRIME MODULE EXCEPT NOSE LOCK

20.            REED SW’S GO TO ALT MODULE EXCEPT NOSE UPLOCK AND MAIN GEARS D/L

21.            HANDLE POS GOES TO PRIME MODULE ONLY

22.            GEAR RED LIT AND STEADY HORN IF GEARS NOT D/L IN LAND CONFIG (FLAP IN LAND RANGE AND THR LEVER IDLE)

23.            IN FLT BRAKE DONE BY HYD4 FROM METERING VLV IF LEVER UP

24.            IF PARK BRK ON A/S WILL OFF AND ITS S/O VLV CLOSED TO TRAP HYD FOR PEDAL LOCK

25.            BRK RESERVOIR USED FOR AUTO BRK AND TOUCH DOWN PROTECTION

26.            TOUCH DOWN PROTECTION: A/S GIVES FULL RELEASE TO PREVENT BRK AT T/D

27.            NORMAL BRK USES HYD4 AND RESERVE BRK USES HYD2

28.            BRK ACC IS ONLY ON HYD4

B747 CHAPTER 29

29

1. HYD POWER:
                       4 ADP (AIR DRIVEN PUMP)
                       4 EDP (ENG DRIVEN PUMP)
                       1 ACP USED FOR HYD4
                       STBY ON HYD1, PRESSURIZES HYD3
2. ALL HYD COMPONENTS ARE IN PYLON EXCEPT RETURN FILTER 2,3 AND STBY   
    PUMP
3. RETURN FILTER MODULE 2,3 ARE IN WING REAR SPAR
4. STBY PUMP IS IN STAB COMPARTMENT
5. HYD3 RETURN LINE USED AS RESERVOIR FOR STBY SYS (AND FEED HYD1)
6. HYD SERVICE STATION IS IN L/H BODY W/W
7. EDP IS AT R/H OF ENG CONN TO AGB
8. A PRESS RELIEFE VLV OPENED AT 3500 PSI
9. LOW PRESS SW OPERATE AT 1200 PSI FOR ADP AND EDP
10. HYD SYS PRESS LIT WILL ON IF BOTH ADP AND EDP LOW PRESS
11. ACP POWERED FROM GND HAND BUS, 115 VAC, 3 PHASE IS IN PYLON
12. LOW PRESS LIT MUST ON FOR ACP RUN
13. ADP SW:
                AUTO: WILL RUN IF EDP PRESS <2600 AND OFF >2800 PSI
                OFF: LOW PRESS LIT ON
                CONTINUOUS: MANUALLY ON
14. EDP SW:
                   NORM: FULL PRESS RUN
                   DEPRESS: SOLE ENER AND CLOSE BLOCK VLV TO BLOCK PUMP OUT
                   SUPP OFF: 2 MIN LIMITED
15. SUPP S/O VLV IS 28VDC CAN BE OFF BY EDP SW OR FIRE HANDLE
16. RESERVOIR 1,4 ARE 9.5 GALLON, AND 2,3 ARE 5.5
17. A QTY IND REPEATS THE SIGNAL OF IND FROM COCKPIT
18. OVERHEAT LIT WILL ON AT 104 °C AND OFF AT 80 °C
19. HEAT EXCHANG IS IN MAIN FUEL TANK
20. STBY SYS WILL FEED PITCH TRIM AND PITCH FEEL IF HYD3 FAIL

B747 CHAPTER 28

28

	2500	1500	13500	35000	45000
SURGE	RES2	RES1	MAIN1	MAIN2	CENTRE	MAIN3	MAIN4	RES4	RES3	SURGE

1.           TOTAL FUEL FOR 747-SP IS 150000KG

2.           RES3,4 IS ONLY IN 747-SP

3.           2 O/R JETISON PUMP IN CENTER

4.           2  J/P IN MAIN 2,3 EACH

5.           FUEL CAN TRANSFER FROM RES TO MAIN VIA TRANSFER VLV BY GRVITY

6.           FUELING CAN DONE WITHOUT POWER, ALL VLV HAVE MANUAL OVERRIDE

7.           TEMP SENSOR IS IN MAIN1

8.           SURGE TANKS HAVE JETISON NOZZLE VLV TO SEND FUEL TO OUTBOARD

9.           FOR GND TRANSFER DESTINATION DEFUEL VLV MUST OPEN AND:

BOOST PUMP ON+ MANUAL DEF/REF VLV ON OR

JETISON PUMPS: DO NOT NEED R/D VLV OR

FROM CENTER TO MAIN: O/R J/P ON+ JET VLV ON

10.        MANUAL D/R VLV CONNECTS FEED LINE TO JET LINE

11.        BOOST PUMPS PRODUCE 25 PSI , J/P ARE 55 PSI

12.        MAN R/D VLV HAS SW ON REMOTE PNL FOR TRANSFER FUEL

13.        TRANSFER FROM CNTR TO INNERS TO OUTERS NEED MAN R/D VLV OPEN

14.        O/R J/P IS IN HIGHER LEVEL THAN BOOST PUMPS SO CNTR NEED A SCAVENGE PUMP TO PREVENT REMAIN EXTRA FUEL IN  CNTR

15.        THERE ARE 12 R/D VLV:

2 FOR EACH CENTR, MAIN2, MAIN3

1 FOR EACH RES, MAIN1, MAIN 4

16.                 EAH ENG FED BY OWN MAIN TANK (ENG1 BY TANK1…)
17.                 4 XFEED VLV PERMIT EACH TANK TO FEED OTHER ENG
18.                OUTER TANKS MUST TRANSFER TO INNERS FOR JETISON
19.                 4 VOLUMETRIC COMPENSATOR:

IN MAIN1, 4

IN MAIN2 FOR MAIN 2, 3

IN RES1 FOR ALL RES

20.                 TANKS VENTED BY DUCTS AND RAM AIR SCOOP AND FLAME ARRESTOR
21.                 SCOOPS PRESS THE TANKS TO MINIMIZE FUEL LOSS
22.                ALL R/D VLV WILL CLOSE WHEN SURGE TANK RECEIVE 40 GALLON BY AN OVERFILL FLOAT SW
23.                MAIN TANKS HAVE FILLING PORT OVER WING
24.                R/D CLOSE IF POWER SHUT
25.                OVER FILL RESET SW ALLOWS FUELING IF SURGES DRAINED
26.                EACH TANK HAS A GAGING COMPENSATOR
27.                GAGE TEST IS DISABLED DURING FUELING
28.                VOL S/O UNIT IN MEC  R/D VLV
29.                VSOU CARDS:

S/O CARD: 1 FOR EACH TANK

DENSITY CARD: PROTECTS OVERFILL OF MAIN1, 4

 VARIABLE RESISTOR

POWER CARD

30.                 TEST GAGE SW CONNECTED TO DENSITY CARD
31.                 O/R J/P HAS CURRENT DET
32.                 IF BOOST PUMP OFF , FUEL CAN GO TO ENG’S BY BOOST PUMO BYPASS VLV
33.                 ALL VLV ACTUATORS ARE I/W EACH OTHER
34.                 IF O/R J/P REPLACED WITH J/P IN INNERS, 3 PUMP MUST USE NOT 4

B747 CHAPTER 27

27

AIL

1. AIL:
        OUTER: -15 TO +25, A LOCKOUT MECH PREVENT OUTER MOVE WHEN FLAP RET
        INNER: -20 TO +20
2. BOTH CONT COLUMN MOVE GOES TO L/H AIL CCA (IS IN R/H WING W/W)
3. R/H CCA PREVENTED FOR SAFETY BY LOST MOTION DEVICE
4. A/P A USES R/H AIL CCA USE HYD3,4
5. A/P B USES L/H CCA WITH HYD1,2
6. AIL POS TX IS ON OUTERS AND SPOILER4,12 (ZERO IND IN HI SPD)
7. AIL TRIM DONE BY AN ELEC ACTUATOR ON L/H CCA
8. 4 FLT CONT S/O VLV FOR AIL AND SPOILERS ARE IN WING REAR SPAR
     AND 4 USED FOR ELEV AND RUDD IN STAB COMPARTMENT

SPOILER

1. 6 SPOILER EACH WING:
                                           5 IN FLT MAX 20
                                           1 IN GND: 6 AND 7 MAX 45°
2. AIL MOVEMENT FROM CCA GOES TO MIXER FOR FLT SPOILER MOVE
3. SPOILER HANDLE LOCKED IN FLT POS
4. RATIO CHANGER OP BY A VLV TO INCREASE SPOILER EXT TO 45°
5. RATIO CHANGER PREVENTS SPOILER5,8 TO MOVE >20 IN FLT
6. GND SPOILERS HAS 3 POS (0,20,45) BUT FLT HAVE ANY POS
7. AUTO SPD BRK LIT ON IF :
                                                   DISAGREE BETWEEN THR AND ACTUATOR
                                                   FAULT OF HYD 1,4
                                                   TILT FAULT
                                                   ELEC FAILURE
8. THR1,3 MUST IDLE TO OPERATE SPD BRK (OR REVERSE2,4)

FLAP

1. LEADING EDGE FLAP:
                                       KRUGER: 11, 12, 13
                                       VARIABLE CAMBER
2. TRAIL EDGE FLAP INBOARD HAS NO BACK BRK AND TORQ LIM
3. LE FLAP HAS 4 HYD PDU:
                                              1 TO 5
                                              6 TO 8
                                              9, 10
                                              11 TO 13
4. EACH PDU HAS ALT ELEC MOTORTE FLAPS HAS 2 PCU:
                     INBORD: HYD1
                     OUTB: HYD4, IT HAS BYPASS VLV TO CUT HYD IN ALT MOTOR OPERATION
5. TE FLAP MAX EXT:
                                   HI SPD (>178KNS): IS 25°
                                   LO SPD: IS 30°
                                   *BY SPD SENSOR IN MEC
6. EACH LE HAS 2 LIT ON P4:
                                                 GREEN: POS REACHED
                                                 AMBER: TRANSIT OR DISAGREE
7. T/O WARN IF LE NOT EXT OR TE NOT IN T/O RANGE OR SPD BRK NOT ARM
8. L/H INB FLAP POS TX GOES TO STALL WARN COMP

STAB

1. STAB HYD MOTORS:
                                 L/H: HYD2
                                 R/H HYD3
2. SECONDARY BRK APPLIED TO GEARBOX OUTPUT
3. RELEASE LIT ON IF BRK NOT APPLIED
4. HYD MOTORS HAVE 4 SOLE FOR: CONT, ARM, A/P, ELEC
5. HYD MOTORS GETAUX PITOT( SPD )AND FLAP POS TO DECREASE RATE IN HI SPD
6. STAB SW:
                 CUTOUT: IN MEC PREVENT MOVE OPPOSITE TO ELEV
                 CUTOFF: ON PEDESTAL TO CUT HYD
7. GREEN BAND LIT (AMBER) WILL ON IF DISCREPANCY BETWEEN ITS SW AND NOSE L/G SW

ELEV

1. A/P USE INNER ELEV PCU
2. POS TX IS ON OUT ELEV
3. ELEV FEEL LIT ON BY FEEL COMPUTOR IF 25% DIFF BETWEEN 2 SYS
4. FEEL COMP INPUTS:
STAB POS
AUX PITOT
∆P SW

5. INNER ELEV CONN TO OPPOSITE OUTER ELEV
6. STALL WARN COMP IS IN P5 (O/H)
7. 747-SP HAS OVER ROTATION COMP IN E1
8. IF OVER ROTATION SENSED IN BODY AND N L/G NOT GND, OVR ROT CMPTR SEND SIG TO STALL WARN TO ACTIVE STICK SHAKER

RUDD

1. RUDD RATIO CHANGER REDUCES DEFLECTION TO 5° AT HI SPD(AUX P/S)
2. RATIO CHANGER HAS NO OUTPUT WHEN APU OR EXT PWR ON
3. 2 POS TX FOR EACH RUDD
4. ON ADI, RATE OF TURN SHOWN BY Y/D COMP

B747 CHAPTER 26

26

1. FIRE PROTEC:

                 ENG: FIRE PROTEC + EXTINGUISH SUPP BY 28VDC BATT AND HOT BUS

                     APU: SAME AS ENG’S

                     W/W: OVERHEAT DET SUPP BY 115VAC FROM AC ESS + 28VDC FROM BAT BUS

2. FIRE DET LOGICS DONE BY RELAYS

3. ENG FIRE HANDLE PULLED:

                                            FUEL VLV CLOSE

                                            PYLON VLV CLOSE

                                            HYD S/O CLOSE

                                            GEN TRIP WITH MAX 10 SEC DELAY

                                            HYD PUMP DEPRESS

                                            FIRE EXTINGUISH ARM

4. BOTTLE LOW PRESS RESET DONE BY CB (MUST RESET AFTER BOTTLE CHANGE)

5. DET CARDS CONSIST OF:

                                            SUPP LOOPS

                                            OUTPUT TO IND AND WARN SYS

                                            FAULT AND FIRE AND SHORT CIRCUIT DISCRIMINATOR

B747 CHAPTER 24

 24

AC GEN

1.               ELEC CENTER:

MAIN (MEC): RACKS AND PWR CENTER

AFT (AEC) OR E8: APU RELAYS, APU BAT CHAGER  

UPPER (UEC) OR E10: MAIN BAT, 4 TR’S, MAIN BAT CHAGER  

AND INV

·         P83 IS IN E8

2.               THERE  ARE:

2 APU GEN: 90 KVA (ONLY 747-100 HAS 2 APU GEN)

4 ENG GEN: 60 KVA

2 EXT GEN: 90 KVA, 250 A (ONLY 747-100 HAS 2 EXT GEN CONN)

2 BAT: (MAIN AND APU), 24V, 34 A OR 36 A

2 BAT CHAGER: 40A

6 TR: 75 A (EXT TR IS 20 A )

1 INV: 1 PHASE, 500VA (IN E10)

4 LOAD CONT

1 VOLT BOOSTER: IS A DC TO DC CONVERTOR IN E10

1 SSB (SPLIT SYS BREAKER): IN SYNC BUS ISOLATES R/H AND L/H

4 BTB: ISOLATE AC BUS’S FROM SYNC BUS

4 GCB:  CONNECT GEN’S TO AC BUS’S

4 GCR:  CAN OFF THE GEN’S

2 APB: APU BREAKER

3.         4 TR ARE IN E10 AND EXT TR IN MEC ALSO CARGO HAND BUS HAS TR IN 747-100 ONLY

4.         GCU CONTROLS: GCR, GCB, BTB

5.         3 TR FOR AC BUS 1,2,3 AND ONE FOR ESS AND ONE FOR EXT ONE FOR CARGO HAND

6.         THERE ARE 6 DC BUS: DC1,2,3 + DC ESS + DC GND HAND + DC CARGO HAND

7.         2 LOAD CONT ARE IN P14 AND 2 ARE P15

8.         STATIC INV IS IN E10

9.         LOAD CONT FUNC:

                         CSD SPEED CONT AND IND

                         JOGGING SIG TO CSD

                         OVER SPEED TRIP SIG

                         LOAD DIVISION BETWEEN GEN’S

10.             

11.            ALL GEN ARE I/W EACH OTHER

12.            APU PRODUCE  POWER MORE THAN ENG’S GEN COZ OF GOOD COOLING

13.            MAIN BAT IS IN E10 IN UEC (UPPER EQUIP CENTER)

14.            APU BAT LOCATED IN TAIL AND USED FOR START AND CONT THE APU CIRCUITS

15.            ALUMINUM WIRE USED TO SAVE WEIGHT BUT IN ENG AND APU COPPER USED

16.            APU DOES NOT CSD COZ ECB HELD CONSTANT SPEED

17.            THERE ARE 11 INTERCHANGEBLE  BREAKER:

4 GCB (GEN CONT BRK)

4 BTB (BUS TIE BRK) CUT POWER OF SYN BUS

2 APB (APU PWR BRK)

1 SSB (SPLIT SYS BRK) DISCONN THE R/H AND L/H

18.      THERE ARE 2 DIFFERENT BREAKER XPC (OR EPC) EXT PWR CONTACTOR

19.      XPC HAS NO TRIP COIL AND  ARE LOWER RATE

20    PARALLELING IS POSSIBLE ONLY FOR ENG GEN’S

21.      APU AND EXT PWR PARALLELING IS PREVENTED BY SSB

22.      INCOM PWR DISCONNECTS THE EXISTING

23.      EXT PWR HAS PRIORITY FOR GND HAND AND GND SRVC BUS

24.     EACH GCB CLOSING :

                               IF SSB IS OPEN : TRIPS OWN SIDE XPC AND APB

                               IF SSB CLOSE : TRIPS ALL , (ALSO APU FIELD CUT)

25.  CARGO HAND BUS POWERED FROM APU2 OR EXT2, EXT2 HAS PRIORITY (THIS BUS IS ONLY IN B747-100)

26.  CARGO HAND BUS AND SYN BUS CAN’T BE POWERED BY SAME SOURCE

27.  CSD IS 8000 RPM

28.  GEN OVERSPEED SENSOR IS ON CSD

29.  A SOL DISCONN CSD FROM GEARBOX AND RESETING ONLY IN GND AND ENG OFF

30.  PRESS  LIT ILLUM IF CSD DISCONN

31.  CSD AND GEN SHAFT WILL SHEAR AT HI TORQUE

32.  IF CSD SPEED IS LOW A HYD ADDED TO OVERDRIVE

33.  IF CSD SPEED IS HI HYD SUBTRACT TO UNDERDRIVE

34.  A SIG FROM LOAD CONT GOES TO TRIM CSD (TRIM COIL OF GOVERNOR)

35.  IF OIL LOW PRESS, CHARGE PRESS SW CLOSED AND PRESS  LIT ON F/E

36.          BYPASS VLV OF OIL/AIR COOLER IS TEMP AND PRESS SENSITIVE OPEN AT 72°C AND 160 PSI

37.          OIL OUT BULB IS UPSTREAM OF SCAVENGE FILTER AND OIL IN BULB IS ON RESERVOIR

38.          SPEED SENSOR:

        BEFOR CLUTCH: FOR IND IN F/E

        ON OUTPUT SHAFT: FOR GCU TO TRIP GCR AT PRESS<440 RPM

39.          UNDER SPEED PRESS SW ON GOVERNOR SEND SIG TO GCU TO TRIP GCR AT 120 PSI

40.          AN ADJUSMENT SCREW CAN INCREASE FRQ ±14 HZ EACH 360° CLOCKWISE

41.          LOAD CONT HOLDS THE LOAD AT 6 KW FOR EACH GEN

42.          GEN’S ARE MAGNETICALLY LOCKED SO CAN’T CHANGE SPEED

43.          TRIP LEVEL IN GCU IS 11.5 KW

44.          OIL IND SHOWS OIL OUT TEMP (120°C NORM) AND OIL RISE (15°C MAX NORM) WHEN SW PRESSED

45.          GEN IS BRUSHLESS CONSIST OF:

                                  PMG

                                  EXCITOR GEN

                                  MAIN GEN

                                  CURRENT TRANSFORMER FOR EACH PHASE

                                  DIODES ON ROTOR

46.          EACH BALL BEARING HAS A SMALLER AUX BEARING WHICH SUPPORTS SHAFT AND SENDS SIG TO BEARING FAILURE LIT IF MAIN BEARING SHEAR

            

47.          BEARING FAIL  LIT ON CSD MUST DISC

48.          KW/VAR IND ON P4:

      MEASURE AND DISPLAY REAL POWER  

      MEASURE AND DISPLAY REACTIVE POWER 

    *CURRENT FROM PHASE B VOLTAGE FROM PHASE A, C

49.            WATT IND USED TO SEE REACTIVE POWER DIVISION WHEN GEN’S PARALLED

50.      VOLTMETER SHOWS LINE VOLTAGE OF PHASE B AND PMG VOLT(80VDC) IF GEN TEST SW PRESS

51.             VOLTMETER READS ABOVE 100V ( COZ OF A ZENER DIODE  )

52.            FRQ/ RPM MEASURES THE  PHASE B FRQ AND CSD RPM

53.          AC ESS SW POS:

GEN1, 2, 3: AC ESS SUPP DIRECTLY FROM ENG’S BEFOR GCB

NORM: AC ESS SUPP BY AC4

OFF

54.    INPUT POWER OF TR’S IS 3 PHASE 115VAC,400HZ

55.    SSB (SPLIT SYS BRK) AUTO DISC BY BOTH BPCU AND WHEN MAN DISC BPCU2

56.    OPEN  LIT ON IF SSB OPENED

57.    APU MECHANICAL FAULTS COZ APB TRIP AND APU S/D

58.    PMG AC VOLT CONVERTED TO DC INSIDE GEN FOR GEN FIELD

59.    AC ESS BUS NORMALLY FEEDS STBY AC BUS AND ESS TR

60.    GALLY POWER CONT BY ELCU (ELEC LOAD CONT UNIT)

61.    F/O AC RADIO BUS POWERED BY AC2 AND CAPT BY AC4

62.    IF OPEN PHASE DET, FIRST BTB TRIPS, THEN IF FAULT EXISTS GCB TRIPS, BUT BTB CAN RECLOSE

63.    FOR FUELLING STBY BUS MUST OFF TO PREVENT SUPPLY TO OTHER EQUIPMENT , STBY PWR ON  LIT GOES OFF (ALSO BAT SW MUST ON)

64.    FAULTS IND OF GEN’S ON P4 BY READ SW

65.    READ AND EARASE SW MUST PRESS TO EARASE

66.    GND HAND AND SRVC BUS POWERED BY EXT1 OR APU1 IN GND

    67.      GND HANDLING BUS IS POWERED AUTO (ONLY IN GND) FROM APU OR EXT WHEN EXT POWER PLUGGED

     68.  GND SERVICE BUS HAS PWR IN FLT FROM AC1, IT FEEDS BAT’S CHARGER, DRAIN MAST, FUEL SYS, …

69.  GND HAND BUS FEED CARGO LOAD, TOWING, CLEAN RECEPTACLE, SRVC INT, … 

70.    APU GEN RPM CONT BY ELEC SPEED CONT IN ETC

71.    UNDER VOLTAGE COZ OF GEN FAIL, OTHER FAULT FROM GCU FAIL

EXT PWR

1.       THERE ARE 2 AMMETER: ONE FOR L/H AUX (APU1,EXT1), ONE FOR R/H FROM PHASE B

2.      

3.     POWER NOT IN USED LIT IS OFF WHEN XPC CLOSED MEANS GS BUS IS POWERED

4.     GND HAND BUS POWERED WITH EXT BUS CONN WITHOUT XPC CLOSE

5.     EXT1 IS AFT ONE

6.     ESS TR POWERED FROM ESS BUS WHICH NORMALLY CONN TO AC4

7.     GND HAND BUS DIVIDED TO 3 SEC: FWD CARGO, AFT CARGO, CARGO DOORS +  LIT AND VACUUM

8.     GND SERVICE BUS DIVIDED TO 2 SEC: UPPER, LOWER

9.     BPCU MONITORS FRQ, VOLT AND PHASE OF EXT POWER 

10.  2 XPC LOCATED IN P14 AND P15

11.  2 GND SRVC RELAY IN P14:

                                            R14 (SELECT RELAY):  CHOOSE APU1 OR EXT1

                                            R15 (TRANSFER RELAY): CHOOSE AC1 OR R14

12.  GND H/R IN P14 AUTO CONN  EXT1 OR APU1 IN GND AND IN P15 FOR CARGO

DC GENERATION

1.               BAT HAS THERMOSTATE ON TOP OPEN AT 58°C

2.               MAIN AND APU BAT ARE I/W

3.               MAIN BAT IS IN UEC AND APU BAT IN APU COMPARTMENT

4.               A HEATING PAD ACTIVATED IN 2°C IN APU BATALSO BLOWER

5.               ONE BAT SW FOR BOTH BAT

6.               EACH BAT HAS:

                  1 THERMOSTAT: UPPER IN ONE CELL FOR O/H

                 2 FREEZ TEMP SENSORS: TO RUN HEATING PLATE UNDER BATT

                 1 TEMP SENSOR: TO RUN BLOWER

7.             TEMP SENSORS ARE BELOW HEAT PLATE

8.               BOTH BAT CHARGER SUPP BY AC GND SERVICE BUS

9.               MAIN BAT CHARGER IS IN UEC (E10)

10.            APU CHARGER AND APR ARE IN AEC(E8)

11.            CHARGER MODES:

                             NORMAL

                             CONSTANT POTENTIAL (HI TEMP): IF V < 27.5 V

                             PULSING: WHEN BAT FULLY CHARGED

12.          INV NORMALLY SUPP BY BATT BUS

13.          INV AUTO RUN TO POWER AC STBY BUS IF AC ESS FAIL AND SW AT NORM

14.          MANUAL ON POS ALLOW TO CHECK INV REGARDLESS OF AC ESS FAILURE OR NOT

15.          VOLT BOOSTER WORK FROM 18 TO 29V AND HOLD BAT VOLT TO 23.5V FOR VHF1,VOR1.G/S1

16.          THERE ARE 4 SW ON P4 FOR ISOLATION OF DC1,2,3 AND ESS

17.            DC ESS BUS NORMALLY FEEDS STBY DC AND BAT BUS

18.            STBY DC POWERED BY BAT BUS IF ESS FAIL

19.            BAT STOP CHARGE AT O/H (58°C)