Electrical

Question 1

When the ground service is bus powered? What is the available when using the ground service bus?

Answer 1

GSB is powered when ground power connected and not selected and batteries are off

Passenger Cabin lights, Lav lights, Galley lights, Courtesy lights, cockpit dome lights, and baggage/service lights

Question 2

Can the GPU be used to recharege the main batteres?

Answer 2

NO

BC1 and BC2 open automaticly when the GPU is selected.

(OM2 2-5)

Question 3

What items are powerd from the inverter via the 115VAC Bus?

Answer 3

TCAS

EGPWS

Winshear

Question 4

Which electrical bus supplies power to the ISIS on the 145XR?

Answer 4

The backup battery hot bus

Question 5

Under what conditoins are shed buses powered while on the ground assuming the SHED BUS knob is not in the OFF possition?

Answer 5

• With the GPU powering the aircraft and the shed bus swich in the auto or override postion.
• With at least one generator online and the shed bus in the override position
• With 3 or more generators on line

(Rule of 1 or 3)

Question 6

What criteria must be established to have shed bus power in flight

Answer 6

3 generators online.

Question 7

Is DME availalbe when in essential power mode?

Answer 7

NO

However, VOR and Localizer based approaches may be flown so long DME is not required

Question 8

Define the EICAS master warning ELEC ESS XFR FAIL

Answer 8

The electrical system has failed to transfer into the essential power mode following a loss of all generators

Question 9

What does the GPU AVAIL inscription on the overhead GPU button mean?

Answer 9

A GPU had been properly connected to the aircraft and some power is available

Question 10

What should be the voltage of the GPU prior to selecting it?

Answer 10

26V to 29V

Question 11

What is the purpose of de-selecting the backup battery on the first flight of the day for XR aircaft?

Answer 11

To isolate the backup battery and the backup battery hot bus. This can be confimred by observihg the ISIS remaing powered. This test CANNOT be done when a GPU is selected or APU is started

Question 12

When may a circuit breaker be reset in flight and what protocol must be followed prior to doing so.

Answer 12

• Only when direced by the QRH
• If the breaker trips again do not reset it
• After completion of the flight a MX descrepancy shal be enetered.
• Resetting fuel supply circuits are prohibited

Question 13

What happens when the ESS PWR button is pressed?

Answer 13

It forces the aircraft into Essential Power regardless of the Electrical Distribution Logic (EDL)