Electrical System, Fire Protection And Detection System

23 Questions | By SasjaZ | Last updated: Mar 21, 2022 | Total Attempts: 105

Questions

Settings

Create your own Quiz

The electrical system for an airliner is a very sensitive subject and a mechanic must ensure there are no possibilities for a fire occurring due to electrical wiring problems, as it can be catastrophic. The quiz below is designed to test out how much you know about wiring a Boeing 737. Give it a shot!

Questions and Answers

1.

What does the illumination of the “elec” light on the electrical panel indicate:
- A.
  
  A fault has been detected in the AC or standby power system.
- B.
  
  A fault has been detected in the DC or standby power system.
- C.
  
  A fault has been detected in the DC and standby power system.
- D.
  
  A fault has been detected in the AC and standby power system.
2.

How is the main battery charger powered:
- A.
  
  By the DC ground service bus 2
- B.
  
  By the AC ground service bus 1
- C.
  
  By the DC ground service bus 1
- D.
  
  By the AC ground service bus 2
3.

With the standby power switch in the AUTO position, what will cause automatic switching to the Alternate power source:
- A.
  
  AC transfer bus 1 or DC bus 2 loses power
- B.
  
  AC transfer bus 1 or DC bus 1 loses power
- C.
  
  DC transfer bus 1 or DC bus 2 loses power
- D.
  
  DC transfer bus 1 or DC bus 1 loses power
4.

After a generator drive disconnect, can the drive be re-engaged:
- A.
  
  Yes, in flight
- B.
  
  Only on the ground (by maintanance)
- C.
  
  Yes on ground (by flight crew)
- D.
  
  No
5.

What is the normal supply to the battery bus:
- A.
  
  By the AC ground service bus 1
- B.
  
  By the DC ground service bus 1
- C.
  
  By the AC ground service bus 2
- D.
  
  By the DC ground service bus 2
6.

When will the switched hot battery bus be powered by a functional battery:
- A.
  
  With APU running
- B.
  
  When Ground Power is connected
- C.
  
  Always
- D.
  
  When the battery switch is selected to ON
7.

What does illumination of the “GND Power Available” light indicate:
- A.
  
  That DC ground power is connected
- B.
  
  That AC ground power is connected and meets airplane power quality standards
- C.
  
  That Ground power can be requested
- D.
  
  That the power is 3 phased and grounded
8.

In flight, what does illumination of the “TR UNIT” light indicate:
- A.
  
  TRU1 or TRU2 and TRU3 have failed.
- B.
  
  TRU1 Failed
- C.
  
  TRU2 Failed
- D.
  
  All TRU's Failed
9.

In flight, the output from no1 IDG fails. How is power AC transfer bus 1 restored:
- A.
  
  Via power x-feed switch
- B.
  
  Manually from AC transfer bus 2 via the AC tie bus.
- C.
  
  Automatically from AC transfer bus 2 via the AC tie bus.
- D.
  
  Automatically from the battery
10.

Following the loss of an IDG, with a single generator operating, which loads are initially shed:
- A.
  
  Galley A
- B.
  
  Galley B
- C.
  
  Galley bus A + B (shed from transfer bus 1)
- D.
  
  Galley bus A + B (shed from transfer bus 2)
11.

What are the normal AC volts and frequancy for the 2 engine driven generators and the APU generator:
- A.
  
  115 v (+/- 5 v) and 400Hz (+/- 10 Hz)
- B.
  
  220 v (+/- 5 v) and 400Hz (+/- 10 Hz)
- C.
  
  115 v (+/- 5 v) and 600Hz (+/- 10 Hz)
- D.
  
  220 v (+/- 5 v) and 600Hz (+/- 10 Hz)
12.

What is the battery voltage:
- A.
  
  24 volts DC. Range is 22 to 30 volts and supplies standby power for 30 minutes (single battery)
- B.
  
  24 volts DC. Range is 22 to 30 volts and supplies standby power for 60 minutes (single battery)
- C.
  
  28 volts DC. Range is 22 to 30 volts and supplies standby power for 30 minutes (single battery)
- D.
  
  28 volts DC. Range is 22 to 30 volts and supplies standby power for 60 minutes (single battery)
13.

DC power is supplied by 3 TR units. What is the output Voltage:
- A.
  
  28 volts DC.
- B.
  
  24 volts DC
- C.
  
  24 volts AC
- D.
  
  28 volts AC
14.

Where does TRU no 2 receive its AC power from:
- A.
  
  AC transfer bus 2
- B.
  
  AC transfer bus 1
- C.
  
  From hot battery bus
- D.
  
  From battery bus
15.

The aircraft is on the ground on stand, with engines running, and both generators on line. External power is available. What will positioning the ground power switch to ON do:
- A.
  
  Trip both engine generators and APU
- B.
  
  Connect external power and keep generators running.
- C.
  
  Trip both engine generators and connect external power and connect external power to the transfer busses.
- D.
  
  Ground power can not be connected with engines running.
16.

With AC power on the bus bars, no system faults, and OVHT DET switches in NORMAL, selecting OVHT/FIRE on the test switch will illuminate wich lights:
- A.
  
  Master FIRE WARNING lights
- B.
  
  Master caution lights
- C.
  
  Master FIRE WARNING lights, ENG1+ENG2 and APU fire switch lights, and WHEEL WELL FIRE light, Plus the MASTER caution lights, OVHT/DET annunciator and the ENG+ENG OVERHEAT lights.
- D.
  
  OVHT/DET Lights
17.

With the OVHT/DET switch in the normal position, and both loobs servicable, when will engine fire warning be activated:
- A.
  
  If one loop detects a fire or a overheat condition.
- B.
  
  When both loops detect a fire condition.
- C.
  
  When both loops detect a overhead condition
- D.
  
  When both loops detect a fire condition or an overheat condition
18.

Illumination of the FAULT light on the Overheat/Fire detection panel indicates what:
- A.
  
  With the Overheat Detector in the NORMAL position, one loop has failed
- B.
  
  With the Overheat Detector in the NORMAL position, Both loops have failed.
- C.
  
  With the Overheat Detector in the AUTO position, Both loops have failed.
- D.
  
  With the Overheat Detector in the AUTO position, one loop has failed.
19.

If a malfunction in one fire loop occurs, with the OVHT DET switch in the normal position, do you still have detection availiable:
- A.
  
  No, if a malfunction occurs, system is not availiable for the rest of the flight.
- B.
  
  Yes. The defective loop is removed, and the remaining loop continues functioning as a single loop detector.
- C.
  
  Yes, but the switch must be put in ALTN selection
- D.
  
  Yes, but a amber OVHT light wil illuminate for the rest of the flight.
20.

The power source for the APU fire extinguishing system is the:
- A.
  
  DC transfer bus 2
- B.
  
  The hot battery bus (28v DC)
- C.
  
  Ground power
- D.
  
  DC transfer bus 1
21.

The power source for the ENG Overheat and Fire Protection detection system is:
- A.
  
  Battery bus (28v DC)
- B.
  
  Hot battery bus
- C.
  
  Transfer bus 1
- D.
  
  Transfer bus 2
22.

When the extinguisher test switch is held in the 1 or 2 position, 3 green lights should illuminate. What does this indicate:
- A.
  
  The associated bottle discharge circuits for all 3 extinguisher bottles are normal.
- B.
  
  That wheel extinguishers are tested and ok
- C.
  
  The bottles are armed and have surficient contense
- D.
  
  The three wheel well areas are tested for overheat.
23.

The engine fire warning switch lock mechanism is automatically unlocked when:
- A.
  
  It is put in AUTO mode.
- B.
  
  Either the fire warning or overheat light illuminates.
- C.
  
  When aircraft is in flight.
- D.
  
  Engine ignition key is put in