2A672 Volume 2 Frequency Converter Components
Volume URE for 2A672 Volume 2
- 1.During operation of the EPU-6/E frequesncy converter it is determined that E and F pin voltage in not needed for the aircraft. The operator places the Loop/bypass/28 V to aircraft switch to what position?
- A.
28 V to aircraft
- B.
Neutral
- C.
Bypass
- D.
Loop
- 2.Which of the following components provides 525 VAC to the control transformer of the EPU-6/E frequency converter?
- A.
Input auto transformer
- B.
Output auto transformer
- C.
Input phase sequence transformer
- D.
Output phase sequence transformer
- 3.What EPU-6/E components receive potential directly from the input auto transformer?
- A.
Analog board and alarm display
- B.
Control transformer and voltage control
- C.
Input circuit breakers and display power supply
- D.
SCR voltage regulator and phase sequence transformer
- 4.The control transformer perform on the EPU-6/E frequency converter provides
- A.
28 VDC for the aircraft contactor
- B.
240 VDC for the aircraft contactor
- C.
120 VAC for the operation of E and F line 28 VDC power supply
- D.
240 VAC for operation of E and F line 28 VDC power supply
- 5.What EPU-6/E frequency converter components must be inspected prior to use?
- A.
Air inlets for blockage
- B.
Wiring for secure mounting
- C.
Maintenance panels for corrosion
- D.
Interior air vents for secure mounting
- 6.During operation you determine that there is an undervoltage fault problem with the EPU-6/E frequency converter unit. What component could be malfunctioning?
- A.
Analog board has failed
- B.
Output trim potentiometer is centered
- C.
Voltage control board potentiometer is shorted
- D.
Audible alarm switch is in the silence position
- 7.During operation of the EPU-6/E frequency converter you determine that one phase voltage is lower than the other two phases. What could cause this malfunction?
- A.
Malfunctioning transister
- B.
Burnt control transformer fuse
- C.
Improper SCR firing adjustment
- D.
Loose push-on connector on the output filter capacitor
- 8.What -95 gas turbine compressor section supplies high-volume, low-pressure air for combustion, cooling, and bleed air output?
- A.
Turbine section
- B.
Accessory section
- C.
Compressor section
- D.
Air regulator section
- 9.The function of the deswirl ring on the -95 gas turbine compressor is to
- A.
Accelerate air
- B.
Increase air pressure
- C.
Decrease air velocity
- D.
Smooth turbulent air flow
- 10.What -95 component isolates the second-stage air from the operation of the first-stage compressor?
- A.
Interstage ducts
- B.
Interstage seal
- C.
Impellers
- D.
Inducers
- 11.What prevents overpressurization of the bearing cavity on a -95?
- A.
Oil jet
- B.
Oil cooler
- C.
Scavenge pump
- D.
Oil tank vent line
- 12.What -95 chambers are pressurized when the butterfly valve is closed?
- A.
1 and 3
- B.
2 and 4
- C.
1, 2, and 3
- D.
1, 3, and 4
- 13.The -95's rate-metering valve prevents the butterfly valve from snapping open by bleeding air through the atmospheric bleed port from chamber
- A.
1
- B.
2
- C.
3
- D.
4
- 14.What -95 component closes to complete the electrical circuit to the fuel solenoid and ignition unit?
- A.
Load switch
- B.
Oil pressure switch
- C.
Turbine start switch
- D.
35 percent centrifugal speed switch
- 15.What preliminary set-up step, if skipped, prevents the -95 from starting?
- A.
Set-up controls
- B.
Set parking brakes
- C.
Open and secure the exhaust door
- D.
Ensure the turbine air inlet and exhaust doors are free of obstructions
- 16.On the -95, discharge air pressure at 100 percent engine speed should indicate
- A.
55 +2 psig
- B.
45 +2 psig
- C.
35 +2 psig
- D.
25 +2 psig
- 17.The -95 does not shut down when the charging rate decreases to 12 amperes. What is the probable cause of this trouble?
- A.
Air load switch
- B.
Fuel level relay K5
- C.
2 speed solenoid SV4
- D.
Battery charging module
- 18.When heat is applied to an ice cube and the ice starts to melt, it is
- A.
Super heat
- B.
Latent heat
- C.
Sensible heat
- D.
Convection heat
- 19.The three methods of heat transfer are
- A.
Sensible, latent, and super heat
- B.
Sensible, convection, and conduction
- C.
Conduction, convection, and radiation
- D.
Conduction, convection, and super heat
- 20.The air flowing through an air conditioner is also called
- A.
Heat
- B.
Heat load
- C.
Pounds per minute (ppm)
- D.
Cubic feet per minute (cfm)
- 21.While you are doing an ops check of an air conditioner, you notice the unit is short cycling. What do you do to correct this trouble?
- A.
Increase the heat load
- B.
Lower the refrigerant charge
- C.
Check the receiver outlet valve
- D.
Decrease the setting of the LPCO
- 22.Bubbles in an air conditioner refrigeration system sight glass probably indicate
- A.
Refrigerant overcharge
- B.
A low refrigerant charge
- C.
High discharge temperature
- D.
Low discharge air temperature
- 23.What MA-3D air conditioner component controls refrigerant flow into the evaporator?
- A.
Quench valve
- B.
TXV solenoid valve
- C.
Hot gas bypass circuit
- D.
Electric expansion valve
- 24.The temperature controller on an MA-3D air conditioner opens the hot gas bypass valve if the
- A.
Air pressure is too low so the boiling point of the R134a must be increased
- B.
Suction air pressure is too high so the boiling point of the refrigerant can be decreased
- C.
Suction pressure is too low so the boiling point of the refrigerant must be increased to increase the output air temperature
- D.
Suction pressure is too high so the boiling point of the refrigerant must be decreased to decrease the output air temperature
- 25.You place the MA-3D air conditioner SW1 in the START position, but the engine does not operate. What is the probable cause of this trouble?
- A.
K7 contacts are closed
- B.
Overspeed switch is closed
- C.
Oil pressure switch is closed
- D.
Override switch is not closed
Questions: 80 | Attempts: 2628 | Last updated: Jun 13, 2018
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Sample QuestionDuring operation of the EPU-6/E frequesncy converter it is determined that E and F pin voltage in not needed for the aircraft. The operator places the Loop/bypass/28 V to aircraft switch to what position?
Questions: 84 | Attempts: 2308 | Last updated: Jan 10, 2013
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Sample QuestionWhat is the simplest form of matter?
Questions: 88 | Attempts: 2105 | Last updated: Jul 9, 2013
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