Term
| When is the engine generator tripped? |
|
Definition
Over/Under voltage
Over/Under frequency
Over current |
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Term
| What does the green "AVAIL" light on external power indicate? |
|
Definition
| External power is available and within limits |
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|
Term
| What is the bus priority for AC bus 1 and 2? |
|
Definition
On-side gen
APU gen
Cross-side gen
External AC |
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Term
| What does the "AUTO XFER FAIL" light on electrical panel mean? |
|
Definition
| Auto bus transfer inhibited due to bus fault or generator over-current |
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Term
| Where does the the AC ESS BUS receiver power? |
|
Definition
|
|
Term
| When are the AC utility buses load shed? |
|
Definition
Single engine ops in flight
Single gen or ext AC only with flaps down on ground
Manually by AC/DC utility |
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|
Term
| ADG - What is the power output? What does it power? |
|
Definition
115v, 400hz, 15kva
AC ESS BUS and 3B HYD pump |
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|
Term
| When does the ADG auto-deploy? |
|
Definition
| Both AC bus 1 and AC bus 2 become unpowered in flight |
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|
Term
| How is power obtained if the ADG fails? |
|
Definition
| DC ESS BUS through BATT BUS through the Emergency DC Xfer Contactor by operating the ADG manual handle |
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|
Term
| How long does battery power last? |
|
Definition
|
|
Term
| Why pull the ADG handle before landing? |
|
Definition
BATT BUS powers DC ESS BUS when ADG slows down
Allows thrust reversers to be stowed |
|
|
Term
| How are the batteries charged? |
|
Definition
Main - AC bus 1
APU - AC bus 2 |
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|
Term
| What does the Auto Xfer "OFF" light mean? |
|
Definition
| Auto bus tie has been manually disabled |
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|
Term
| What does pulling the ADG handle do? |
|
Definition
Releases ADG
Energizes emergency AC/DC Xfer contactors
Energizes HYD 3B Xfer contactor |
|
|
Term
| "EMER POWER ONLY" warning |
|
Definition
ADG is supplying ESS bus
AC bus 1 and 2 are not powered |
|
|
Term
| Where do DC BUS 1 and 2 receive power? |
|
Definition
DC BUS 1 - TRU 1 then TRU 2
DC BUS 2 - TRU 2 then TRU 1 |
|
|
Term
| Where does the DC ESS BUS receive power? |
|
Definition
ESS TRU 1 and 2
APU BATT BUS
Batteries (through Emer DC Transfer Contactor) |
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|
Term
| Where does the DC EMER BUS receive power? |
|
Definition
| APU BATT DIR BUS and BATT BUS |
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|
Term
| Where does the BATT BUS receive power? |
|
Definition
ESS TRU 1 and 2
APU BATT DIR and MAIN BATT DIR BUSes |
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|
Term
| Where do DC UTIL BUS 1 and 2 receive power? |
|
Definition
DC UTIL BUS 1 - TRU 1
DC UTIL BUS 2 - TRU 2 |
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|
Term
| How is AC power provided during an in-flight emergency? |
|
Definition
|
|
Term
| How many AC power sources are available? |
|
Definition
5
Left & right engines
APU
ADG
External power |
|
|
Term
|
Definition
|
|
Term
| Which circuit breaker panels contain the AC and DC ESS BUSes? |
|
Definition
CBP3 - AC ESS
CBP4 - DC ESS |
|
|
Term
| How many DC power sources are available? |
|
Definition
TRUs
Main battery
APU battery
External DC |
|
|
Term
| What is the purpose of the Main Bus Tie switch? |
|
Definition
| Allows both DC buses to be powered by a single TRU |
|
|
Term
| Can the ADG Unit be tested in the air? |
|
Definition
| Yes, takes 5.7 seconds for the light |
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