IDG DRIVE parameters?
- IDG HI OIL TEMP
- IDG LO OIL PRESS
“HOTLOP”
Indication of successful IDG DRIVE DISC?
Both DRIVE light + GEN CONT OFF will illume
* GEN CONT switch remains ON with flow bar in view
Normal DRIVE + GEN CONT config prior to ENG start?
DRIVE ON illume (Low Oil PRESS)
GEN OFF illume (BTC CLOSED)
GEN ON w/flowbar (Switch Position Indicator Only)
* both extinguish once engine is started
Significance of OFF light on L/R GEN CONT?
Indicates that the generator breaker is OPEN
*either engine shutdown or fault is detected
Significance of OFF light for APU GEN?
- APU GEN control switch is OFF
- Fault has isolated the GEN.
DOES NOT indicate OFF when APU GEN breaker OPENS per system logic.
<em>* normally remains illume at all times</em>
What happens to the electrical system after 1st ENG is started on EXT PWR?
Its respective GEN will automatically replace EXT PWR on its AC BUS.
Primary purpose of HDG?
Provides non-time limited GEN capable of operating essential systems for ETOPS.
* LND GEAR LEVER to the left excluding EICAS + Autobrakes
When does HDG activate?
Automatically whenever both AC buses lose electrical power in flight.
What 7 buses does the HDG provide for?
- HOT BATT
- BATT
- DC STBY
- AC STBY
- L AC XFER
- R AC XFER
- CA XFER
Indication of dual AC BUS FAIL?
- Blank FO EFIS
- Blank EICAS
- Activated SEI
What indication may be associated with initial HDG activation?
<em>*with regards to battery</em>
DISCH may illume when HDG starts as BATT discharges down to output voltage of supplied HDG power.
CA RDMI on HDG PWR?
- CA RDMI get HDG info from R IRS
- On HDG, R IRS switches to DC and will operate for only 5 minutes.
- L + C IRUs are operated continuously.
therefore…
FO must select IRS switch to ALTN to allow C IRS to continue providing HDG info to CA RDMI
When is GND HANDLING BUS powered?
Only on ground by APU or EXT PWR
* EXT PWR need only be AVAIL - EXT PWR has priority between the two.
What does GND HANDLING BUS power?
- Cargo Compartment Lights
- Cargo Doors
- Refueling
How is GND SERVICE BUS powered?
ON GND, can be connected to GND HANDLING BUS with switch located at L1
however….
Any time R AC BUS is powered or GND HANDLING BUS is un-powered, the GND SERVICE BUS auto-reverts back to R AC BUS
What does the GND SERVICE BUS power?
- BATT CHARGERS
- MISC Loads
What is the only alternate power source for L/R AC XFER BUSES?
HDG
* these buses power ETOPS essential equip and remain powered in event of dual main AC BUS FAIL
Primary purpose for items on L/R AC XFER BUSES?
ETOPS EQUIP
IF both AC BUSES fail, how are CA flight instruments powered?
HDG
* remember, LND GEAR and left
HOT BATT BUS items?
- FIRE PROTECTION
- SPAR/APU FUEL VLV
- PARK BRAKE VLV
- CLOCK (non-digital portion)
- RAT Deploy
BATT DC BUS items?
- ENG + APU + CARGO FIRE DET
- DC Fuel Pump
- SEI
- FWD Cockpit Dome Lights
How is STBY PWR system tested?
Turn STBY POWER switch to BAT. Observe DISCH illumes and STBY POWER OFF remains extinguished.
*BATT CHARGERS are disconnected
AUTOLAND electrical flow and when is it engaged?
L A/P = L AC BUS
R A/P = R AC BUS
C A/P = HOT BATT BUS
* engaged when APP is armed on MCP
What 3 conditions result in load shedding?
OVERLOAD (SINGLE- SOURCE)
(Protect APU/EXT w/No ENG RUN):
- C FUEL PUMPS INHIBITED (N2< 50%)
- C HYD ELEC PUMP #2 SHED
- UTILITY/GALLEY may shed
- UTILITY have to be manually reset
- UTILITY/GALLEY may shed
ENGINE START (w/APU only GEN SRC):
- 1st ENGINE START:
- BOTH UTILITY/GALLEY SHED
- L HYD DEMAND PUMP
- 2nd ENGINE START:
- Respective UTILITY/GALLEY BUS SHED
GEN LOSS (Takeoff + In Flight):
- BOTH UTILITY/GALLEY SHED
- Armed by TL Advance
- BUSES restored w/new GEN online
