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54 Cards in this Set

  • Front
  • Back
4 sources of AC power?
2 engine driven generators, AC external, APU generator
GRD POWER AVAILABLE blue light means?
External power is available (no info on quality). Stays on while in use. *External AC bus is powered*
What is the caution regarding the EXTERNAL POWER CONN light?
If it's on and EXTERNAL POWER NOT IN USE is out, do not disconnect external power.
BPP is?
Bus Protection Panel. Tastes external power for you and allows both Ground Power Relays (GPR) to close if it's good.
When is Galley Power shed?
During single generator operation
Ground Service Switch. Where is it, what does it power, and where does it get power from? When does it automatically switch off?
FWD FA panel. Connects external power directly to ground service bus only (utility outlets, battery charger, cabin lighting). Electromagnetically held in on, auto off if EXT PWR lost or generator bus 1 is powered.
Generator and Main Busses provide power for what kind of systems?
non essential items (galley power and cabin lighting) and high-load items (electric hyd pumps and window heat)
Transfer busses power?
Main instrument controls, displays, and some essential items (eg, EHSI, EADI, FMC, CDUs, engine ignition, anti smash lts)
When a generator is lost, where does the transfer bus get its power from?
Offside Generator Bus
Battery charger normal power source? Transfer power source?
Generator bus 1 transfers to main bus 2
T/R 1 powers:
T/R 2:
T/R 3:
DC bus 1
DC bus 2
Battery Bus
what happens in the event of a TR failure
Other two take over, except in case of TR 3. In this case battery bus goes to the hot battery bus.
Purpose of the battery
APU start and emergency power for essential equipment.
Loss of both generators, battery supplies power (30 min) to which 5 buses?
-Hot Battery Bus
-Switched Hot Battery Bus
-Battery Bus
-AC standby bus
-DC standby bus
What 3 conditions are needed for an automatic transfer of both standby busses occur?
STANDBY POWER switch is in AUTO, the airplane is airborne, and EITHER transfer bus 1 OR DC bus 1 loses power.
Manually positioning the STANDBY POWER switch to BAT does what?
AC standby bus, DC standby bus and battery bus switch from primary power source to secondary power source.
Primary and secondary power sources for AC standby bus, DC standby bus, and battery bus?
AC: transfer bus 1; battery bus thru static inverter
DC: DC bus 1; battery bus
Battery bus: TR3 ; hot battery bus
STANDBY POWER to OFF does what?
Disconnects power from AC and DC standby busses, regardless of primary power source availability. Does not affect Battery Bus.
When does amber STANDBY PWR OFF light illuminate?
When AC standby bus is not powered (light doesn't monitor DC standby bus).
STANDBY POWER switch does not affect which bus?
Switched Hot Battery Bus
Two sources for battery charger?
Primary: GND service bus via generator bus 1
Secondary: Main bus 2 via generator bus 2
What will happen if you push RESID VOLTS button with generator control breaker and generator field relay closed?
The airplane blows up. No, not really. But you can damage AC voltmeter.
GFC open what indications show on CPS FREQ meter and AC VOLTS meter?
Needles pegged to left. Can check residual voltage in this configuration.
BAT switch ON and OFF, what are the power sources for the switched HBB and the BB?
ON: switched hot battery bus powered by the battery charger, the battery, or DC ext. Battery bus powered by TR3 or hot battery bus
OFF: removes DC power from switched hot battery bus and battery bus.
BAT switch OFF and STANDBY POWER switch to BAT?
Battery bus gets power from hot battery bus, but switched hot battery bus remains unpowered.
When do flourescent background lights illuminated at a fixed intensity?
Loss of transfer bus 1 (now powered by AC standby bus)
What lights are NOT tested by Master lights switch? (3-4)
-marker beacon
-autoflight annunciator (A/P, A/T, FMC)
-parking brake
-(on some airplanes) master fire warning lights
illuminates when gear is down or TEF not up...
Power SOURCE for T/R 1:

T/R 2:

T/R 3:
-Transfer bus 1
-Transfer bus 2
-Main Bus 2
What happens if BUS TRANSFER switch is placed to OFF?
Automatic transfer of power cannot occur. Used to provide isolation of two sides in event of electrical malfunction.
Where do each of the three T/R's get their AC power?
1: Transfer bus 1
2: Transfer bus 2
3: Main bus 2
Explain operation of DC tie-bus.
When open, isolates T/R1 from T/R 2 and3.
When is the DC tie-bus open?
BUS TRANSFER switch to off, or automatically when glideslope capture w/at least 1 FD or 1 AP engaged in CMD. For cat II/III cert.
24VDC battery range?
22-30 Volts
Describe battery charging.
After usage the DC ammeter shows a high charge rate. At approx 16 amps, goes to a 2 minute pulse cycle. Ammeter at zero indicates fully charged battery.
Does battery charge during APU start?
No, automatically disconnected by APU start battery charger cutout relay to prevent charger overheat.
Some things lost with Generator 1?
-Landing Light Combo
-Windshield Heat Combo
-2 fuel pumps (onside Fwd, ctr offside)
-L elev pitot heat
-offside elect pump
-equipment cooling
Some things lost with generator 2?
Same as 1
T/R 3
Recirc fan
Engine Vib monitor (non EIS)
Equipment cooling Alternate
What three things does the BUS TRANSFER switch in OFF do?
-prevents operation of transfer relays
-Opens DC disconnect relay
-Prevents battery charger from switching to secondary power source.
What does Break before Make mean?
AC, existing power source is always disconnected automatically before the oncoming power source is connected.
You have both generator busses powered by the APU on the ground. You forget, and takeoff this way. What will happen?
Nothing. It's designed to only power one in flight, but it won't drop one automatically if you takeoff with both on the APU. You have to take one off manually.
How does the APU generator maintain a constant operating speed?
No CSD, fuel controller on APU does it.
What does the GCU do?
Does not allow a generator to be connected to the electrical system unless the generator output voltage and frequency are within preset limits.
T/R 3 powered by and gives power to?
Powered by Main Bus 2 and supplies primary DC power to the battery bus.
What is the power source for the Fuel Crossfeed Valve and Light?
Hot Battery Bus
What does the RESID VOLTS Button do?
Allows AC VOLTS meter to display residual voltage of the selected generator. If the generator drive is disconnected, the residual voltage indicates near zero
What does T/R 1 position of the DC Meter Selector do?
Displays DC amperage load of T/R 1 and DC voltage of DC bus 1.
Momentary actuation of either DISCONNECT switch results in what?
Generator disconnect wheter or not the engine is running. Reset can only be accomplished on the ground.
RISE Scale shows what?
Temperature difference of the generator drive oil input and output ports. A high temperature rise indicates excessive generator workload.
IN scale shows what?
Generator drive oil input. A high temperature indicates inefficient generator drive cooling, usually accompanied by low rise temp and a HIGH OIL TEMP light.
When does the FASTEN BELTS switch in the AUTO position illuminate the FASTEN BELTS signs?
Landing Gear Lever DN
Flap Lever out of UP
What is the airspeed restriction on the outboard landing lights?
None. Nada. Zip. Extend or retract them any time you want Mav.
What happens if the Taxi Light is left on and the gear is raised?
Nothing. It burns away with the intensity of a billion white hot suns.
What is special about the left dome light bulb?
It is not controlled by the DOME WHITE switch, it operates as part of the emergency exit light system.