Electrical Flashcards
THE DC GND HDLG XFR BUS CAN BE POWERED BY:
HOT MAIN BAT
EXTERNAL POWER
BAT SWITCH SELECTOR OFF, NO ENGINE RUNNING MEANS:
DC ESS BUS, DC STBY BUS, INV1 AND AC STBY BUS ARE ISOLATED FROM THE HOT MAIN
BAT BUS
DC EMER BUS IS ISOLATED FROM THE HOT EMER BAT BUS
NO EXTERNAL POWER, NO ENGINE RUNNING, AND BAT SW OFF, WHICH ITEMS DOES THE
DC GND HDLG XFER BUS POWER?
REFUEL AND DEFUEL SYSTEMS, CARGO DOOR AND COCKPIT/CABIN ENTRANCE LIGHTING
(2 MINUTES WHEN SELECTED WITH THE MAIN DOOR OPEN)
THE DC AUXILIARY HYDRAULIC PUMP, VIA PEDESTAL PB
“BAT SW” SELECTED ON, NO ENGINE RUNNING, ALLOWS:
EXT PWR OPERATION OR A REDUCED DC SUPPLY FOR QUICK PRELIMINARY COCKPIT
PREPARATION IN ORDER TO START THE RIGHT ENGINE IN HOTEL MODE
THE NORMAL VOLTAGE READING FOR A BATTERY IS:
FOR A BATTERY WITHOUT LOAD 25-28 VOLT
FOR A BATTERY UNDER LOAD 23-28 VOLT
WHAT ARE THE CAPACITIES OF THE BATTERIES?
MAIN BAT 24 V/ 43 AH, EMER BAT 24 V/ 17 AH
A/C ON GROUND “EXT PWR” LIGHT “AVAIL” ILLUMINATED, TO POWER THE DC
DISTRIBUTION SYSTEM YOU MUST:
PLACE BAT SW SELECTOR ON AND PRESS THE EXT PWR PB
THE DC SVCE BUS CAN BE POWERED BY
DC EXT PWR, ONLY THE DC SVCE PB ON THE CABIN ATTENDANT PANEL HAS CONTROL
EVEN WITH BAT SW OFF
DC BUS 1 IF THE DC SVCE/UTLY BUS PBS IN THE COCKPIT AND THE CABIN ATTENDANT
PANEL ARE ON
HOW MANY BUS TIE CONTACTORS (BTC) AND BUS TIE RELAY (BTR) ARE CONTROLLED BY THE
MAIN ELEC PWR PANEL “BTC” PB?
TWO, ONE BETWEEN DC BUS 1 AND DC BUS 2; ONE BETWEEN AC BUS 1 AND AC BUS 2
A/C ON GROUND, DC EXT PWR ON, DC BTC “ISOL”;
DC BUS 2 AND AC BUS 2 ARE SUPPLIED FROM EXT PWR
WHEN DC GENERATOR IS FUNCTIONING AS A STARTER DURING A BATTERY STA
IT IS ELECTRICALLY SUPPLIED BY THE HOT MAIN BAT BUS AND CONTROLLED FROM THE DC ESS
WHAT IS THE FUNCTION OF THE EMER BAT WHILE THE ENG START ROTARY SELECTOR IS SET
TO START OR CRANK?
IT PROVIDES POSITIVE POWER TO PROTECT CRITICAL ITEMS FROM POWER TRANSIENT.
IT NEVER POWERS THE STARTERS
ONCE THE STARTER GENERATOR HAS STARTED THE ENGINE, IT OPERATES IN THE
GENERATOR MODE WHEN PASSING:
NH 61.5%
WHAT IS THE NORMAL VOLTAGE OF THE DC GENERATORS?
28 VOLTS
A/C ON GROUND, ENGINES RUNNING, DC EXT PWR AVAILABLE AND ON LINE:
DC EXT PWR HAS PRIORITY OVER ENG DC GEN
ASSUMING NORMAL OPERATION IN FLIGHT, HOW IS THE CONSTANT AC PWR FREQUENCY
OBTAINED:
FROM DC BUSSES THROUGH TWO INVERTERS
ASSUMING NORMAL OPERATION IN FLIGHT, WHEN ARE THE HOT EMER BUS AND HOT MAIN
BAT BUS CONNECTED TO THEIR RESPECTIVE BATTERIES:
ALWAYS
ASSUMING NORMAL OPERATION IN FLIGHT, WHEN ARE THE DC EMER BUS AND DC ESS BUS
CONNECTED TO THE DC BUS 1 AND/OR DC BUS 2:
ALWAYS THROUGH BAT CHG AND ITS RESPECTIVE HOT EMER OR HOT MAIN BAT BUS
INVERTER 1 NORMALLY SUPPLIES:
AC BUS 1 AND AC STBY BUS
DC SVCE AND UTILITY BUS SHED AMBER LIGHT COMES ON WHEN:
AT LEAST ONE UTILITY BUS IS DISCONNECTED FROM ASSOCIATED MAIN DC BUS
THE “EMER BAT CHG” FAULT LIGHT COMES ON WHEN:
BATTERY OVERHEAT, DETECTED BY MFC (AUTOMATIC DISCONNECTION)
A FAILURE OF THE CHARGE CONTACTOR
FOLLOWING AN INVERTER FAILURE, “INV” LIGHT ILLUMINATED:
ASSOCIATED AC BUS IS SUPPLIED THROUGH THE AC BTR BY THE OTHER INVERTER
IN CASE OF MAIN BAT OVHT WITH MAIN BAT CHG FAULT LIGHT ON, WHAT HAPPENS TO THE
BUSSES POWERED BY THAT BATTERY?
THE HOT MAIN BAT BUS IS LOST AND DC ESS BAT BUS IS POWERED BY DC BUS 1
IN FLIGHT WITH ONE ENGINE OPERATING, WHICH INDICATION WOULD BE DISPLAYED ON
THE SHUTDOWN ENGINE’S DC GEN PB:
WHITE OFF IF PB IS RELEASED
AMBER FAULT IF PB IS DEPRESSED (IN)
ENGINE RESTART WITH THE DC GEN PB IN (DEPRESSED) WHAT SHOULD HAPPEN TO THE PB
LIGHT WHEN THE GENERATOR COMES UP TO NORMAL OPERATING SPEED:
GEN FAULT AMBER LIGHT SHOULD GO OUT
IN FLIGHT ONE ARROW ILLUMINATED ON THE EMERGENCY SUPPLY SHOWS:
THE SUPPLY OF DC ESS OR DC EMER BUS FROM THE CORRESPONDING HOT BATTERY
BUS AND BATTERY DISCHARGING
THE “DC BTC” IS AUTOMATICALLY CLOSED AND THE FLOW BAR IS ILLUMINATED IN CASE OF:
EXT PWR OPERATION, HOTEL MODE OPERATION, OR SINGLE ENGINE OPERATION
IN THE EVENT OF BOTH DC BUS 1 AND DC BUS 2 SUPPLY LOST:
INV 1 IS AUTOMATICALLY SUPPLIED BY THE HOT MAIN BAT BUS OR BY THE HOT EMER
BAT BUS IN OVRD CONFIGURATION (OR BY TRU IF EQUIPPED AND SELECTED ON)
NOT COUNTING UTILITY AND SERVICE BUSSES, WHICH DC/AC BUSSES CANNOT BE SUPPLIED
WHEN ON BATTERIES ONLY?
DC1 – DC2 – AC1 – AC2
FOR THE TRU (TRANSFORMER RECTIFIER UNIT) IN CASE OF DUAL DC GEN LOSS:
WITH TRU PB ON, THE ACW BUS 2 IS CONNECTED TO DC EMER BUS, DC STBY BUS, INV 1
(AC STBY BUS ONLY)
WITH BATTERIES ONLY, AC BUS 1 AND AC BUS 2 ARE:
Never supplied
“ BAT” SELECTOR TOGGLE “SW” ON “OVRD” MEANS THAT:
NO CHANGING ABOUT THE SUPPLY, EACH EMER, ESS AND STBY BUS ARE FORCED TO BE
CONNECTED TO THEIR RESPECTIVE BATTERIES, OVERRIDING ALL OTHER LOGICS AND PROTECTIONS
THE UNDV LIGHT ILLUMINATES AMBER WHEN:
DC STBY BUS VOLTAGE IS LOWER THAN 19.5 VOLTS
STBY BUS OVRD PB SET ON OVRD MEANS THAT:
DC STBY BUS AND AC STBY BUS THROUGH INV 1 ARE SUPPLIED FROM DC HOT EMER
BUS
NO EXT PWR AVAILABLE, DOES OPERATING IN HOTEL MODE PROVIDE POWER FOR THE ACW
SYSTEM:
No
HOW CAN THE ACW SVCE BUS BE POWERED BY ACW EXT PWR:
DIRECTLY FROM ACW EXT PWR, GREEN AVAIL LIGHT ILLUMINATED, BUT THE
ATTENDANT PANEL ACW SVCE BUS SWITCH MUST BE ON (LIGHT ILLUMINATED)
WHAT IS THE MINIMUM NP (PROP SEED ROTATION) TO ENSURE ACW GEN OPERATION?
70% (RANGE OF 341 TO 488 HZ)
A/C ON GROUND AND ACW EXT PWR SELECTED ON, STARTING LH ENGINE AND PUTTING LH
CL MAX RPM:
ACW BUS 1 AND ACW BUS 2 ARE STILL SUPPLIED BY ACW EXT PWR
IN THE ACW SYSTEM, HOW MANY BTCs (BUS TIE CONTACTORS) ARE USED:
TWO BTC AND ONE BTC PB
THE BUS TIE CONTACTOR (BTC) IN THE ACW ELECTRICAL SYSTEM PERMITS:
IF ONE ACW GEN FAILS THE OTHER PROVIDES POWER TO BOTH ACW BUSSES
TO PROVIDE POWER TO BOTH ACW BUSSES WHEN EXT PWR IS USED
A/C ON GROUND, ENGINES RUNNING, EXT ACW PWR SUPPLYING THE BUSSES, WE SELECT
ACW BTC ON ISOL:
ACW BUS 1 AND 2 ARE LOST
WITH ALL 4 AIRCRAFT GENERATORS PB IN (DEPRESSED), AND EXT PWR SUPPLYING BOTH ACW AND DC, WHICH LIGHT SHOULD BE ILLUMINATED IN THE FOUR SHIP’S GENERATOR PB:
AMBER FAULT, TO SHOW AN OPENING GENERATOR CONTACTOR
A/C IN FLIGHT, ACW GEN 1 FAILS:
ACW SVCE BUS ONLY IS SHED
WHEN THE ACW SVCE BUS IS SHED, WHAT INDICATION(S) IS/ARE GIVEN:
SHED AMBER LIGHT ON ATTENDANT PANEL ACW SVCE BUS PB
