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Mesa EJET > Electrical System > Flashcards

Electrical System Flashcards

1
Q

IDG 1 and IDG 2 Selector Knob

-AUTO

A

This position allows the IDG contactor to close, connecting the IDG to the respective AC BUS automatically, according to system logic

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2
Q

IDG 1 and IDG 2 Selector Knob

-OFF

A

Opens the IDG contactor isolating the IDG from the respective AC BUS

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3
Q

IDG 1 and IDG 2 Selector Knob

-DISC

A

Must be held in this position for one second to mechanically disconnect the IDG

Can’t be reconnected in flight

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4
Q

Normal AC Bus Priority

A

Onside IDG
AC BUS Tie
Offside IDG

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5
Q

Illumination of the Amber LED next to IDG DISC

A

Indicates to which pilot which IDG to disconnect

Will illuminate in association with the IDG 1(2) caution EICAS message & will extinguish when IDG is disconnected.

HOTLOP
-High oil temperature or Low oil pressure

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6
Q

AC BUS TIES Selector Knob

-1 OPEN

A

Opens the Bus Tie Contactor (BTC) 1, segregating AC BUS 1 from the AC BUS Tie

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7
Q

AC BUS TIES Selector Knob

-AUTO

A

This position allows automatic operation of the BTC’s according to system logic

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8
Q

AC BUS TIES Selector Knob

-2 OPEN

A

Opens the Bus Tie Contactor (BTC) 2, segregating AC BUS 2 from the AC BUS TIE

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9
Q

AC BUS Tie Priority

A

APU
GPU
IDG

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10
Q

GPU Button

-PUSH IN

A

Connects the AC GPU to the AC BUS Tie, according to the source priority

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11
Q

GPU Button

-PUSH OUT

A

Isolates the AC GPU from the AC BUS Tie

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12
Q

GPU Button

-AVAIL Light

A

AVIL will illuminate with the button pushed in or out when the AC GPU is connected, but is not powering the AC BUS Tie. Also indicates GPU is set to correct power setting.

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13
Q

GPU Button

-IN USE Light

A

Will only illuminate when button is pushed in & the AC GPU is powering the AC BUS Tie

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14
Q

APU GEN Button

-PUSH IN

A

This position allows the APU generator to connect to the AC BUS Tie, automatically according to source priority

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15
Q

APU GEN Button

-Push OUT

A

Opens the APU generator contactor and isolates the APU generator from the AC BUS Tie. The APU is tripped off line and de-excited

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16
Q

TRU ESS Toggle Switch

-AUTO

A

This position allows automatic connection of the TRU ESS to the DC ESS BUS 3

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17
Q

TRU ESS Toggle Switch

-OFF

A

Isolates the TRU ESS from DC ESS BUS 3

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18
Q

TRU 1 and TRU 2 Toggle Switches

-AUTO

A

This position allows automatic connection of the TRU 1(2) to the respective DC BUS 1(2)

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19
Q

TRU 1 and TRU 2 Toggle Switch

-OFF

A

Isolates the TRU 1(2) from the respective DC BUS 1(2)

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20
Q

BATT 1 Selector Knob

-ON

A

The battery is connected to the DC ESS BUS 1

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21
Q

BATT 1 Selector Knob

-OFF

A

The battery supplies power to HOT BATT BUS 1 only

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22
Q

DC BUS TIES Toggle Switch

-AUTO

A

This position allows automatic operation of the DC Tie contactor’s (1 DCTC / 1 & 2 ETC’s) according to system logic

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23
Q

DC BUS TIES Toggle Switch

-OFF

A

Opens all DC Tie contactors

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24
Q

BATT 2 Selector Knob

-AUTO

A

This position connects BATT2 to either the DC ESS BUS 2 or the APU START BUS automatically, according to system logic

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25
BATT 2 Selector Knob | -OFF
The battery supplies power to HOT BATT BUS 2 only
26
AC Power
``` 2 IDG's (115 VAC, 400 Hz, 40 KVA) 1 APU (115 VAC, 400 Hz, 40 KVA) 1 AC GPU (115 VAC, 400 Hz, 40 KVA) 1 RAT (115 VAC, 400 Hz, 15 KVA) 1 Inverter (250 V) ```
27
1 IDG can power both AC Buses
On ground & In-flight
28
APU can power both AC Buses
On ground & In-flight up to FL330
29
GPU can power both AC Buses
On ground only
30
Primary source of AC power
IDG
31
IDG Selector Knob
AUTO- System logic controls contactor OFF- Opens contactor DISC- Mechanically disconnects the CSD from IDG
32
Can the flight crew reconnect an IDG
No, maintenance function only
33
Amber Light accompanied by an EICAS oil message indicates?
IDG disconnect is required
34
ICC
Integrated Control Center (4) | -Line replaceable
35
SPDA
Secondary power distribution assembly (2) - An electric load management unit - Receives power from ICC's - Distributes power according to system logic
36
CSD
Constant speed drive Converts variable engine speed into constant generator speed
37
IDG oil system is cooled how?
Air cooled
38
GCU
Generator control unit
39
Illumination of the amber LED next to IDG DISC indicates?
HOTLOP | -High oil temperature or low oil pressure
40
APU
Auxiliary Power Unit | -Secondary source of AC Power
41
Required for APU Start?
BATT 1 & 2 or BATT 1 & DC GPU
42
Which BATT is used to control APU's FADEC?
BATT 1
43
Why is BATT 2 isolated from the network during APU start?
To exclusively power the APU START BUS
44
Minimum VDC for APU Start?
22.5 VDC
45
Minimum VDC required to close batter contactor?
18.0 VDC
46
Minimum BATT 2 temperature for start?
-20 C
47
AC GPU
AC Ground Power Unit | -Secondary AC power source
48
GPU power can be turned on in 3 locations
- Cockpit Overhead Panel - AC GPU Panel (only powers ground service bus) - Opposite FWD Lav (only powers ground service bus)
49
Normal AC Electrical Priority
On-side IDG APU GPU Cross-side IDG
50
Inverter
- Powers the AC STANDBY BUS when normal AC power source is not available - Allows "A" igniters to always have power source
51
RAT
- Ram Air Turbine - Emergency AC Power source - No restriction for deployment - Manual deployment available
52
RAT supplies power to which BUS
AC ESS BUS
53
Minimum airspeed for RAT
130 knots | -As airspeed decreases, load shedding occurs until AC ESS BUS is not longer powered
54
DC power provided by?
Transformer Rectifier Unit (TRU) -28 VDC, 300 A 2 Batteries -24 VDC, 27 AH 1 DC GPU -28 VDC
55
Primary source of DC power?
TRU's
56
Function of TRU
Convert 115 VAC to 28 VDC
57
RAGO
AC System Priority R- Respective IDG A- APU G- GPU O- Opposite IDG
58
Electrical Emergency Situation | -Batteries Only
- Screen 2 (PFD) - Screen 3 (EICAS) - IESS - Clock - FO MCDU - CA CCD - 2 Comm panels - CA Display panel - CA Reversionary panel - Light for magnetic compass
59
DC HOT BATT BUS 1
- Engine 1A Fire Extinguisher - Engine 2A Fire Extinguisher - Engine Fuel SOV 1 - Hydraulic system SOV 1 - Engine 1 oil level indication - Courtesy / Service lights - DC ceiling lights
60
DC HOT BATT BUS 2
- Engine 1B Fire Extinguisher - Engine 2 B Fire Extinguisher - Engine Fuel SOV 2 - Hydraulic system SOV 2 - Engine 2 oil level indication - CMC - Panel refuel - Water and waste system
61
``` EPC BATT 1(2) Over temp ```
Associated Battery..............................OFF Note-- Do not start the APU
62
Batteries
(2) NiCad Batteries - Secondary source of DC power - Back-up for DC ESS BUS - Charged via any AC power source through TRU's - 18.0 volt min to close battery contactor - Will provide 10 minutes of power during an electrical emergency
63
DC GPU
- Can replace BATT 2 during APU start | - Can only be turned on by a ground ramp button
64
Function of ICC's and SPDA's
ICC's collect and confirm the power is safe and then sends it to the SPDA's, which distributes it
65
How many networks make up the electrical system on the airplane? Why?
2 independent networks for redundancy and fault isolation
66
What happens if a power generating source fails?
Bus ties automatically connect to provide no system degradation
67
What components power the AC system?
``` 1 IDG's APU Inverter RAT AC GPU ```
68
What components power the DC system?
2 NiCad batteries 2 TRU's DC GPU
69
How does the IDG maintain a stable power output?
A constant speed drive (CSD) attaches the IDG to the AGB (accessory gear box)
70
What monitors and controls the IDG's?
Each has a generator control unit
71
Can one IDG power the entire electrical system?
Yes
72
What will cause the amber IDG light on the overhead panel to illuminate?
High oil temp Low oil pressure HOTLOP
73
If an IDG is manually disconnected can it be reconnected in flight?
No
74
What is the primary purpose of the AC generators?
To power the AC BUSSES and AC ESS BUS which power the 3 TRU's (1, 2 & ESS)
75
What is the purpose of the TRU's?
To convert 115 VAC to 28 VDC
76
Can an APU replace a failed IDG?
Yes
77
What is the AC electrical system's priority?
Onside (IDG) Inside (APU) Outside (GPU) Cross-side (Other IDG)
78
How is it known that an AC GPU is hooked up to the airplane and ready to provide electricity?
GPU button displays AVAIL and the GPU icon is presented on the electrical synoptic page -Once the GPU button is pushed in, the button will display IN USE provided another AC power source is not available
79
What does it mean if the AC GPU is plugged in and the outside GPU panel button displays IN USE?
- Ground service bus is in use | - Cockpit GPU button will display AVAIL even though the ground service bus is in use
80
If the airplane is using the AC GPU and the APU is started what should the pilot be sure to do?
Deselect the GPU button before the next GPU connection
81
What will charge the batteries?
Any AC power source
82
How long will the aircraft's batteries last with no recharging?
10 minutes
83
What is the purpose of the DC GPU receptacle?
For APU start when batteries
84
What is the minimum battery temp for APU start?
-20 C
85
What is the minimum voltage to close the battery bus ties?
18 volts
86
What battery is used for the APU start?
BATT 2 powers the APU Start Bus | BATT 1 powers the FADEC & EICAS for monitoring
87
What is the purpose of the inverter?
Converts 28 VDC from the batteries to 115 VAC to power the AC STANDBY BUS when an AC source is not available
88
What is on the AC STANDBY BUS?
Engine exciters 1A & 2A
89
What powers the RAT?
Airflow turns the RAT propeller which spins the turbine inside
90
When will the RAT deploy?
Automatically deploys if AC BUSSES are not powered or manually by pilot
91
How long after deployment before the RAT will supply power?
8 seconds
92
Is there a total loss of power during the 8 second RAT deployment?
No. Batteries supply power to the DC ESS BUSSES and AC STANDBY BUS
93
What does the RAT power?
ESS BUSSES
94
What is the minimum airspeed for the RAT?
130, load shedding occurs below this speed
95
When is the RAT icon is displayed on the electrical synoptic page?
When the RAT is deployed
96
What manages the electrical system?
4 Integrated Control Center's (ICC) & | 2 Secondary Power Distribution Assemblies (SPDA)
97
What is an ICC?
An electrical control device which provides power distribution and protection for electrical loads
98
What is an SPDA?
An electrical load-management unit (powered by the ICC's) that distributes electrical loads to aircraft systems according to distribution logic
99
Can the flight crew reset the ICC and SPDA remote electronic CB's
- ICC CB's can only be reset by maintenance | - SPDA CB's can be reset via the MCDU

Mesa EJET (10 decks)

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