Systems Ch. 5 Electrical

Card Set Information

Systems Ch. 5 Electrical
2012-07-13 18:16:37
Saab 340B Electrical System

Electrical System
Show Answers:

  1. What are the power sources for the DC elctrical system
    • Batteries
    • External Power
    • Generators 
  2. What are the 4 separate parts of the electrical system
    28V DC (main and emergency), 115/26V AC, "Wild" frequency 115V AC
  3. What makes up the 28V DC electrical system
    • 2 main batteries and 1 emergency battery
    • 2 Engine Generators
    • External Power 
  4. How many Ni-Cad batteries does the Saab 340 have
  5. What type of main batteries does the Saab 340 have
    24 volt 43 amp hour Ni-Cad
  6. Where are the main batteries located
    In the respective wing-fuselage fairing
  7. How are the batteries ventilated for cooling
    By ram air in flight, and fans on the ground
  8. What bus is used for batter charging
    Respective GEN bus with at least one generator online
  9. Which bus is the right battery connected to
    Right GEN bus
  10. What powers the Emergency Bus
    The L BAT BUS (batteries must be ON/OVRD) or the Emergency Battery
  11. When does the Emergency battery begin to power the EMER BUS
    When the L Battery power is lost
  12. Where is the Emergency Battery located
    Avionics rack
  13. What is the power source for the emergency power system
    The 28V DC system or the emergency battery
  14. What is indicated by an illuminated NO BAT START light
    Battery temp has reached 57C
  15. What is indicated by an illuminated BAT HOT light
    Battery has reached 71C
  16. What is indicated by an illuminated EMER PWR light
    Eighter the emergency bus in not supplied power or the battery has decreased below 24V
  17. What is the purpose of the Series/ Parallel relay
    During battery start of the first engine the batteries are connected in series to produce 48 volts
  18. What type of Battery is used for the Emergency battery
    24V 5 amp hour lead acid battery
  19. What is indicated by an illuminated L/R BAT HOT light
    Associated battery temp has reached 71C
  20. What other light(s) would be on when a BAT HOT light is illuminated
    • BAT
    • ELEC^ on CWP 
  21. What automatically happns when a battery temp reaches 71C
    BAT relay opens
  22. Can the battery supply power to the GEN buss with a BAT HOT
    Yes, in an emergency the BAT switch can be set to OVRD
  23. What would cause the GPU to automatically disconnect
    • Overvoltage (over 31v)
    • Under voltage (under 10v)
    • Voltage drops below 10 volts with start switch held to L or R 
  24. What is the voltage limit during a start with the start switch held to start
    voltage may drop to 7 volts 
  25. What is the amperage of the 28V GPU
    1400-1600 amps
  26. What is the minimum voltage required to get the magnetic latch toclose for the GPU usage
    10 volts
  27. What does the blue EXT PWR AVAIL light indicate
    GPU is connected to the A/C and supplying at least 7 volts
  28. How many generators on each engine
    2 (DC & AC)
  29. When is the starter/ generator acting as a starter
    During engine start when Ng is between 0-55%
  30. Are batteries being used for a cross generator start
    Yes, the batteries assist the generator to achieve a faster cooler start
  31. When is the GEN relay automatically opened
    • GCU detects a malfunction (except overheating)
    • External power is used
    • Fire handle has been pulled 
  32. When is the Gen relay light expected to be on
    • Gen switch off
    • External power connected
    • Fire handle pulled
    • Engine Ng is less than 55%
    • Gen failure 
  33. How many electrical busses does the Saab 340 have
  34. What minimum Ng is required to connect the starter/ generator to the GEN BUS
  35. What is indicated by an illuminated L/R GEN light 
    The respective Gen relay is open (gen offline) 
  36. The starter/ generators are rated at what voltage
    28 volts
  37. An illuminated GEN OV TEMP light on the overhead panel indicates what
    Generator is overheated (above 150C)
  38. Can the Generators be "online" with EXT PWR on
    No, the relay automatically opens
  39. What 3 conditions must be met for the GEN relay to close
    • EXT PWR must be off
    • Engine start complete 
    • Gen field reset 
  40. What is indicated by an illuminated L/R MAIN BUS light
    The associated main bus is unpowered
  41. What is indicated by an illuminated L/R ESS BUS light
    Associated bus is not powered
  42. What is the purpose of the Bus Tie relay
    To connect the left and right busses to run off one power source
  43. What is indicated by an illuminated BUS TIE CONN light
    The bus tie relay is closed
  44. What are three reasons the Bus Tie relay closes
    • EXT PWR is on
    • Only one Generator is operating
    • Eigther the LEFT or BOTH Batteries are on 
  45. What is the purpose of the bus tie over-current relay
    To protect the Main Distribution system in case of a short
  46. Bus Tie relay opens if the over-current exceeds how many amps
    800 amps
  47. Can the Bus Tie over-current be reset manually 
    Yes, through the K-1 reset button
  48. What is required to close the Utility Bus relay (RCCB)
    EXT PWR on or both generators on
  49. What powers the Emergency Avionics Bus
    The Emergency Bus, when the ESS AVION switch is on
  50. Where does the battery bus receive power from normally
    Gen bus
  51. The left battery is connected to which bus
    Start bus
  52. While on battery power alone what lights illuminate on the DC ELEC panel
    • L/R GEN
    • L/R MAIN BUS
    • EMER PWR (if BUS is below 24V) 
  53. With the GPU powering the A/C what lights illuminate on the DC ELEC panel
    • White EXT PWR
    • L/R GEN
    • L/R MAIN BUS 
  54. What is the power source for the 115/26V AC system
    2 115/ 26V AC inverters powered by the DC system
  55. What is indicated by an illuminated INVERTER light
    Inverter switch is set to OFF or associated 115 volt inverter has failed
  56. With a failure of the 26V output of the inverter what warnings are given
    No CWP warnings or cautions, but an RMI failure and VOR CDI failure will occur
  57. What is the power source for the "wild" frequency 115V AC system
    2 engine drinven AC generators
  58. What is the "wild" frequency 115V AC power used for
    Ice Protection
  59. Why is the AC GEN called the "wild" frequency
    Frequency varies with prop RPM, (460Hz to 640Hz)
  60. Where is the "wild" frequency generator locator
    In the prop gear box
  61. What is the minimum prop RPM for an AC GEN to supply power
    1000 RPM
  62. If prop RPM drops below 1000 RPM, how is the AC GEN reset
    Automatically resets when prop RPM increases above 1000 RPM
  63. What does an illuminated AC GEN light indicate
    Generator is off line
  64. What items can be powered by the Emergency battery
    • A udio System backup power
    • B us-Tie relay connection function
    • E ngine Fire detection L/R
    • T ail Pipe Hot detection L/R
    • W arning System backup power
    • E mergency Volt Indicator
    • E mergency Avionics Bus--- VHF Comm 1/ STBY Horizon
    • S tandby instrument lighting 
  65. What items are on the EMER AVIONICS BUS
    VHF COMM 1, STBY Horizon
  66. What 3 conditions must be met for a battery relay to close
    • BAT switch on
    • EXT PWR off
    • Battery temp below 71C 
  67. What cools the DC generator
    Ram air in flight and fans on the ground