Electrical system Flashcards Preview

From Flashcardlet > Electrical system > Flashcards

Flashcards in Electrical system Deck (27)
Loading flashcards...
0
Q

What is the normal battery used for?

A

Used for starting and ensures emergency power

1
Q

There are two batteries, what are they

A

Normal & emergency battery

2
Q

What is the emergency batt used for?

A

Ensures emergency power and assists in engine starts

3
Q

Describe the batteries:

A

Both are 24V
Ni-Cd
Main Bat is 43 amp hr
Emer bat is 15 amp hr

4
Q

Electrical system is ____ volts

A

28 volts

5
Q

Which lights work in Basic Mode (Battery only).

A
The F/O’s dome light
STBY Compass light
MIN CAB lights
3 flood lights (C side)
Overhead flood light
STBY instrument lights
Eng inst lights
L3 lights on CAP
6
Q

What bus powers the Captain’s wipers?

A

DC BUS 1

7
Q

Will the intercom system between you and the FA work in basic mode?

A

No. The ATTND CALL system is powered from DC BUS #2, which is NOT a Basic Mode Bus

8
Q

What does the MIN CAB LT switch do, and how does it work?

A

The MIN CAB LT switch is used to turn on every other lateral light on the right side of the cabin. When power is lost from the DC Service Bus, a contactor will close enabling the DC ESS BUS to power every other light on the right side of the cabin when you switch in the MIN CAB LT switch. This switch is normally used in an emergency situation, such as engine fire on the ground or dual DC Gen failure

9
Q

What is the difference between the ON position and the OVRD position on the battery switch?

A

When you select the Battery switch to the ON position, you are closing 3 relays that will connect the Hot Battery Busses to their respective “Basic Mode Busses.” (DC EMER BUS, DC ESS BUS, DC STBY BUS, AND AC STBY BUS through INV 1.) Also, in Basic Mode, both Battery Charge Contactors are open. When you select the Battery switch to the OVRD position, you are guaranteeing “Basic Mod” by forcing open both battery charge contactors (EBCC and MBCC) if for some reason they didn’t open. You are also taking away the BPCU logic. (The BPCU regulates distribution and bus isolation by automatic control of certain contactors.)

10
Q

What does the undervoltage light mean?

A

This means the power from the Main Battery is down to 19.5 volts and it’s time to select the OVRD push-button

11
Q

When in Basic Mode, what electrical configuration would you get if you push the OVRD pus-button?

A

Selecting the OVRD push-button enables you to power the DC STBY BUS and the #1 INV through the Emergency Battery. The rest of the relays remain the same.

12
Q

What are the conditions to get an X-start fail light?

A

You must be on the ground and starting the second engine without external power. The X-Start fail light will only illuminate between 10-45% NH if the operating DC GEN does not assist with the start.

13
Q

How do you know the BTC is closed?

A

Illumination of the green flow bar in the push-button. And the other half of the electrical panel is operating.

14
Q

What amber lights on the Main Electric Panel will be on in Basic Mode? (Assume all push-buttons are in.)

A

“10 lights” When you select ON the Battery Switch without external power being AVAIL, the amber FAULT lights in both the DC GEN push-buttons, and the SHED light in the DC SVCE/UTLY BUS push-button will be illuminated. Also, both DC BUSS OFF light will be illuminated as will the Emergency Supply Arrows. The amber BUS OFF for the AC BUS #1 and the BUS OFF and INV FAULT for the AC BUS #2 will be illuminated.

15
Q

What amber lights on the Main Electric Panel will be illuminated with the loss of DC Bus #2?

A

DC GEN #2 FAULT, SHED light in the DC SVCE/UTLY BUS, DCBUSS OFF #2, BUS OFF for AC BUS #2 for 10 seconds followed by continuous INV FAULT for AC BUS #2.

16
Q

What are 4 ways to power the DC Ground Handling Bus?

A

(a) Opening the Cargo Door Control Panel, (b) Opening the Refueling Door Panel. (c) Opening the Main Cabin Door and pushing the 2-minute light switch. (d) Push the AUX HYD push-button. On the ground only.

17
Q

What Busses are powered in Basic Mode?

A
The Hot Emer Bat Bus and the Hot Main Bat Bus are always powered regardless of the Battery switch position because they are directly connected to their respective batteries. Basic Mode Busses are: 
DC EMER BUS. 
DC ESS BUS. 
DC STBY BUS. 
AC STBY BUS through INV #1.
18
Q

What percent of NH will the DC Generator come on line?

A

61.5% NH.

19
Q

What does it mean when the SHED light illuminates on the DC SVCE/UTLY BUS?

A

One or both Utility Busses has been disconnected by the BPCU because of an overload.

20
Q

Can the DC Service Bus be powered if the cockpit DC SVCE/UTLY BUS push- button is de-selected?

A

Yes, but only if external power is supplying the aircraft in the AVAIL only status and therefore Main Bus 1 is not powered. If Main Bus 1 is powered you are going to have to have the DC SVCE/UTLY BUS push-button in the cockpit selected ON.

21
Q

At what point does AC inv 1 become powered by DC bus 1?

A

Anytime DC bus 1 is online

22
Q

At what point does DC standby bus change from getting powered by main battery to emergency battery (via emergency bus)?

A

Beginning of start sequence

23
Q

To shed load onACW, what can you turn off?

A

Strobes
Landing lights
Taxi lights

24
Q

When does the seatbelt/no smoking signs come on automatically regardless of switch position?

A

Cabin pressure >10k

25
Q

What are the 5 sets of lights that don’t illuminate with the annunciator light test?

A
Fuel quantity low level lights
ITT over temp
Status lights
Chan 1+2 lights (C side)
Oil cooler flap lights (FO side)
26
Q

What is ACW powered?

A
Strobes
Landing lights
Taxi lights
Ws heat
Prop heat
Probe heat
Both hyd pumps