ELEC

Question 1

Components of the Electrical system

Answer 1

• 2 Engine Generators and 1 APU Generator
• Each Gen can provide AC to ALL Electrical Busses
• Three-phase 115/200 V 400 Hz Constant-Freq AC system
• 28 Volt DC
• Emergency Generator
• Static Inverter to convert Battery DC to AC

Question 2

What are the two main purposes of the Generator Contol Unit GCU?

Answer 2

• Control the Freq and Voltage of GEN output
• Protect the network by controlling the associated Generator Line Contactor (GLC)

Question 3

What is the power output of the Engine Generators?

Answer 3

• 90 KVA
• 115 and 200 V and 400 Hz

Question 4

What is the output of the Emergency Generator?

Answer 4

• 5 KVA
• 115 and 200 V 400 Hz

Question 5

What is the output of the Static Inverter?

Answer 5

• 1 KVA 115V 400 Hz
• Converts DC Battery to AC to supply power to the AC Essential when aircraft speed is below 50 kts

Question 6

How is DC power supplied?

Answer 6

• Through Transformer Rectifiers (TR)
• Convert AC to 200 A of DC current

Question 7

How many batteries and Amp hour?

Answer 7

• Two 28 V DC Batteries
• 23 Ah

Question 8

Types of Circuit breakers:

Green?

Black?

Red?

Answer 8

Green (Monitored)

• When out for more than 1 Minute, the C/B TRIPPED warning is triggered

Black (Not monitored)

Red

• Wing Tip Brake WTB
• Have red caps on them to prevent from being reset

Question 9

BAT (1/2) pb-sw in AUTO

The Batteries are connected to the DC BAT BUS in the following cases?

Answer 9

• APU starting and less than 95% N
• Voltage below 26.5 V (Battery Charging) - Charging end when charge current goes below 4 A - On ground Immediately, In Flight after 30 minute delay
• Loss of AC BUS 1 & 2 when below 100 kt (Emer Gen not supplying)
• Battery 1 supplies AC STAT INV BUS
• Battery 2 supplies DC ESS BUS