Atlas - 409MC > Electrical > Flashcards

Electrical Flashcards

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1
Q

What does the “AVAIL” light indicate on the External and APU PWR switches?

A

• The related power source (APU or EXT) is plugged in and the power quality is acceptable and available.

6.10.4

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2
Q

What bus is powered on the ground when the APU generator 1 or external power 1 is available?

A

• Ground handling bus

6.20.5

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3
Q

When is the main deck cargo handling bus powered?

A

• When the “AVAIL” light is displayed on the APU 2 or EXT 2 switches.

6.20.8

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4
Q

What electrical power source would you select if cargo handling is required?

A

• The number one auxiliary or external power

6.20.8

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5
Q

When is the ground service bus powered?

A

• When A/C bus 1 is powered, either on the ground or in flight

When the Ground Service Switch is on and Ext or APU power is Avail

6.20.5

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6
Q

What is the function of the Standby Power Switch in the Auto Position?

A

• Allows the main and APU standby busses to be powered from available sources.

6.10.2

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7
Q

Where would you find the Electrical Power-up procedure?

A

Note:Refer to the FCOM, Vol. 1, Supplemental Procedures

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8
Q

What does a Bus Isolation (ISLN) light illuminated indicate?

A
  • BTB open
  • AC bus isolated from synchronous bus

6.10.6

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9
Q

What happens when you push a Generator Drive Disconnect (DRIVE DISC) switch?

A
  • Disconnects IDG from engine when above idle speed
  • Open related Generator Control Breaker

6.10.6

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10
Q

What condition would automatically disconnect the IDG if not manually disconnected by the flight crew?

A

• Excessively high drive oil temperature

6.20.3

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11
Q

How do you reconnect an IDG that has been disconnected?

A
  • Maintenance action is required
  • The IDG cannot be restored by flight crew action

6.10.6 / 6.20.3

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12
Q

What does a Generator DRIVE light indicate?

A
  • IDG oil pressure low, or
  • IDG oil temperature high, or
  • GCB open due to uncorrectable generator frequency fault

6.10.7

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13
Q

What are some of the equipment items powered by the Utility busses?

A

A - (2-F-F) (C-G): A 2 Far Forward CG

  • APU T/R
  • Forward main pumps 2 and 3
  • Forward override/jettison pumps 2 and 3
  • Center override/jettison pump
  • Galley equipment (freighter)

6.20.7

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14
Q

Describe the electrical load shedding process.

A

• Utility bus loads are shed one at a time through the electrical load control unit (ELCUs) in a programmed sequence until the overload condition is relieved.

6.20.1

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15
Q

What is the purpose of the electrical system overload protection?

A

• To ensure power is available to critical and essential equipment.

6.20.1

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16
Q

During load shedding, would you expect to see an EICAS Advisory message ELEC UTIL BUS L, R?

A

• No, this message is inhibited during load shedding

6.20.1

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17
Q

What are the main AC electrical power sources?

A
  • Four IDGs
  • Two auxiliary power sources (APU generators)
  • Two external power sources

6.20.2

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18
Q

Describe the function of the Split System Breaker (SSB).

A

• Divides the synchronous bus, allowing each side of the AC electrical system to be powered by separate auxiliary or external power sources.

6.20.2

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19
Q

Describe the electrical system sequence of events during engine start with the SSB open.

A
  • The IDG powers its side of the synchronous bus when voltage and frequency are acceptable.
  • The previous power source is disconnected.

6.20.2

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20
Q

Describe the electrical system sequence of events with a single power source powering the synchronous bus, when an engine is starting, SSB closed.

A
  • The IDG powers the entire synchronous bus when voltage and frequency are acceptable.
  • The SSB remains closed and the original power source is disconnected

6.20.2

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21
Q

Which bus powers the Captain’s transfer bus?

A

Capt is odd

  • AC bus 3
  • If AC bus 3 is unpowered, AC bus 1 powers the Captains Transfer bus

6.20.6

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22
Q

Which bus powers the First Officer’s transfer bus?

A

FO is 2nd in command

  • AC bus 2
  • If AC bus 2 is unpowered, AC bus 1 powers the First Officers transfer bus.

6.20.6

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23
Q

Which bus provides backup power for both transfer busses?

A

1 is all you need

• AC bus 1

6.20.6

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24
Q

What are some of the equipment items powered by the ground service bus?

A

F-F-M-M: Double FM - Turn the Music ON

  • Fuel pumps for APU start
  • Flight deck flood, navigation, and service lights
  • Miscellaneous service outlets and equipment
  • Main and APU battery chargers

6.20.5

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25
How can the ground service bus be powered when AC bus 1 is not powered, while on the ground?
• By pushing the ground service switch on the cabin panel at door L1, the ground service is then connected to the same power source as the ground handling bus. 6.20.5
26
What are some of the equipment items powered by the ground handling bus?
L-F-P: Load, Fuel, Pump * Lower cargo handling equipment and compartment lights * Fueling system * Auxiliary hydraulic pump 4 6.20.5
27
What bus powers the APU standby bus?
Capt Calls for APU Start • The Captain’s transfer bus 6.20.6
28
How is the electrical system configured during an automatic ILS approach(auto-land)?
* AC and DC busses 1,2, and 3 are isolated from the sync bus * AC bus 4 continues to power the synchronous bus 6.20.8
29
What are some of the major COMPONENTS of the AC standby power system?
M-M-M-S: 3 M&M'S * Main and APU standby busses * Main and APU batteries * Main and APU standby inverters • Standby Power selector 6.20.9
30
What is the normal source of power for the main standby bus?
Main Capt is Odd • AC bus 3 6.20.9
31
How does the main STANDBY bus get power if AC bus 3 becomes unpowered in flight, all other conditions normal?
L •The main standby inverter powers the main standby bus, through the main battery charger, through the main hot battery bus (the main battery normally powered by AC bus 1 through the ground service bus.) 6.20.9
32
If both AC bus 3 and AC bus 1 are not powered, all other conditions normal, how is the main STANDBY bus powered, and for how long can it be powered?
• The main standby inverter powers the main standby bus, from the main battery through the main hot battery bus. (since the battery charger is unpowered, the main battery can provide power to the main standby bus for a minimum of 30 minutes). 6.20.9
33
What are some of the equipment items on the main STANDBY bus?
Communicate your ETA, Fly, Ignite w/ RMI * EFIS control panel, EICAS Interface Unit (EIU), CDU, ILS, VOR - Left * EICAS - Primary display, standby instrument lights * transponder - Left * ADC - Left * fight control components - Various * ignition for all engines - Standby • RMI (if installed) 6.20.9
34
What are the equipment items on the APU standby bus?
Aviate, Navigate * Left FMC * Left ND * Left PFD 6.20.10
35
How is DC power provided by the electrical system?
* Four transformer-rectifier units (TRUs) produce DC power, each TRU powered by its related AC bus. * Four DC busses are connected through DC isolation relays to the DC tie bus. * Battery busses distribute DC power in addition to the four main DC busses 6.20.13
36
What is the normal power source for the main and APU battery busses?
• DC bus 3 6.20.13
37
If either AC bus 3 or DC bus 3 is unpowered, how is each battery bus powered?
• Its related hot battery bus 6.20.13
38
What are some examples of individual equipment items on the main battery bus?
MainLine AA AA FLT IP * ACP: L - Interphone, VHF, Tuning panel * APU controller (alternate) * Fuel valves (all engines), All crossfeed valves, * Lights Dome, storm, and selected indicator lights * Trailing edge flap control * IDG disconnect (all engines) * pressurization control (manual) 6.20.13 / 6.20.14
39
How is each hot battery bus normally powered?
* The ground service bus * Through its related battery charger * Each battery is connected directly to its related hot battery bus 6.20.14
40
What are some examples of equipment items on the main hot battery bus?
ASA EF: ASA Engine Fire * APU fuel shutoff valve * Spar valves (all engines) * APU and lower cargo fire extinguishers * Engine fire extinguishers (all engines) * Fire switch unlock (all engines) 6.20.14
41
What are some examples of equipment items on the APU hot battery bus?
L-I-A: LIA * Left and right outflow valves * IRU left, center, and right DC power * APU inlet door, APU controller (primary) 6.20.14
42
What is the purpose of the Ground Service switch next to the L-1 door?
Connects the ground service bus to the same power source as the ground handling bus when AC Bus 1 is not powered. 6.20.5
43
With only the Battery switch on, what busses are powered?
4 – Main battery bus and APU battery bus The Main Hot Battery Bus and APU Hot Battery Bus are always powered, whether the Battery switch is on or off 6.20.13
44
With the Battery switch ON and Standby Power switch in Auto, how many busses are powered?
6 – Main and APU Hot Battery Busses (always on), Main and APU Battery Busses, and Main and APU Standby busses. 6.20.13 / 6.10.2
45
What is the function of the Standby Power switch in the AUTO position?
Allows Main and APU Standby Busses to be powered from available sources. 6.10.2
46
How do you know when the Standby bus is powered during power up?
The Captain’s PFD, ND, FMS-CDU and primary EICAS are working. 6.20.10
47
When is the Ground Handling bus powered? | .
On the ground when APU Generator 1 or External Power 1 is available 6.20.5
48
When is the Ground Service bus powered?
On the ground or in flight whenever AC Bus 1 is powered. If AC Bus is not powered, then can be powered though same source as is powering Ground Handling bus, and L-1 switch is pushed 6.20.5
49
When is the Main Deck Cargo Handling Bus powered?
On the ground when External power 2 or APU generator 2 is available 6.20.8
50
What happens when the BTB opens automatically?
Disconnects the AC bus from the Sync Bus 6.20.4
51
What happens when you push the BTB switch?
Disconnects the AC bus from the Sync Bus. Opens the related DCIR 6.20.4 / 6.20.13
52
What happens in the airplane electrical system during an autoland?
On an automatic precision approach below 1500 feet radio altitude, AC and DC busses are automatically isolated providing independent power sources to their respective autopilots. AC bus 4 continues to power the Sync bus as a backup. 6.20.8
53
What powers the APU standby bus during normal operations?
Captain Calls for the APU The Captain’s Transfer Bus (powered from AC bus 3) 6.20.6
54
What items are powered by the APU standby bus?
Aviate, Navigate Left PFD, Left ND, and left FMC 6.10.2
55
What is the source of power to the battery chargers?
The ground Service bus 6.20.5
56
What is the normal source of power to the main standby bus?
AC bus 3 backup main standby inverter 6.20.9
57
What normally powers the Capt’s transfer bus?
AC Bus 3 6.20.6
58
What normally powers the First Officer’s transfer bus?
AC Bus 2 6.20.6
59
What is the backup power source for the F/O’s and Capt’s transfer busses?
AC bus 1 6.20.6
60
What will cause a generator drive light to illuminate?
IDG oil pressure low IDG oil temperature high GCB open due to uncorrectable frequency fault 6.10.6
61
What will cause the IDG to disconnect automatically?
Excessively high drive oil temperature 6.20.3
62
What items are powered in flight with loss of all normal AC power (loss of all generators)? Can I fly an ILS? Can I trim? Can I get the gear and flaps down?
Left FMC, left PFD, Left ND, Left VHF comm., dome light, Upper EICAS, Left and right interphone panels, Capt’s pitot heat and on some airplanes the captain and first officers EFIS is available Can I fly an ILS? Yes, but no Flight Director or Autopilot.. The leading edge flaps cannot be extended prompting a Flap Drive message, requiring a 25-knot additive to VREF The control wheel trim switches are inoperative; however the alternate trim switches on the aisle stand are operable. The right inboard and outboard trailing edge flaps indication is available, but trailing edge flap indication on the left side is not. Antiskid is not available. Auto speedbrakes (manual OK), and thrust reversers are also not available. (ref. FCTM page 8.6)
63
What are some of the equipment items powered by the DC Bus Power?
Cabin, Fuel, A/I(Ice), HYD CFI - H Cabin Pressure Pack Temp Controllers Fuel Jettison Fuel Transfer and jettison valve control Engine Driven and Hydraulic demand pump control Individual nacelle anti-ice control Wing Anti-ice control
64
What are some of the equipment items powered by the FO transfer bus
Aviate, Navigate, Comm Auto-Throttle servo PFD - R ND - R ADC - R EIU, EFIS control - R FMC -R CDU - R EICAS display(lower) HF -R
65
What are some of the equipment items powered by the main AC busses
TN FF PW ``` TRU Navigation Radios Flight control computers Flight deck lightning Pitot heat window heat ```
66
What are some of the equipment items powered by the Main Deck Cargo handling bus
N-MM Nose & Side cargo doors Main deck Cargo Handling Equipment Main deck cargo lights
67
What are some of the equipment items powered by the Captain Transfer bus
Aviate and Communicate Backup EEE H EIU - Center EFIS - Center EICAS - Center HF - L
68
What are some of the equipment items powered on the APU Battery Bus
E-F-F-I-H Engine, Fuel, Fire, Inter-phone for, Help Engine Air start Fuel pump - APU DC Fire/overheat detection loops A&B APU & Engine Inter-phone: Cargo, FO, Service, PA Horn: APU fire Warning
Atlas - 409MC
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