Electrical

Question 1

When does the starter become a generator?

Answer 1

50+/- 2 N1

Question 2

How many generators are there?

Answer 2

• 2 x DC (Engine driven)
• 1 x AC (MGB Driven)

Question 3

What is the electrical supply?

Answer 3

• 28 VDC 115A (Max 200A)
• 26 VAC

Question 4

What does the ACGCU Do?

Answer 4

• Over-voltage
• Under-voltage
• Voltage regulation
• Feeder fault

Question 5

What does the DCGCU Do?

Answer 5

• Over-voltage
• Under-voltage
• Under-current
• Reverse current
• GFC (Ground Fault Circuit)

Question 6

Can the AC Gen test be carried out at Idle?

Answer 6

No - has to be done above 92%NR

Question 7

Which Side is the ESS Bus on?

Answer 7

Gen 1

Question 8

How many DC Bus Bars are there?

Answer 8

4
- DC ESS
- 1DC Primary
- 2DC Primary
- Battery

Question 9

How many AC Busses are there?

Answer 9

5
- AC Monitor (3 phase)
- 1AC Primary
- 1 26 VAC
- 2AC Primary
- 2 26 VAC

Question 10

What do you lose if you suffer an [INV FAIL]?

Answer 10

• AFCS (temporarily)

Because the AHRS feeds the AP with a 26VAC line

Simply re-engage the AP

Question 11

What does AC GEN BRNG mean?

Answer 11

That the primary bearing has failed and you have 5 hrs to land.

Question 12

What is the starter cycle duty limits?

Answer 12

60 on, 60 off, 60 on, 15 mins
30 on, 30 off, 30 on, 15 mins (without fuel ignition).

Question 13

If you lose both GCUs (Gens) and AC2, what could have happened?

Answer 13

BAG FIRE
The bag fire light is on a Primary BUS, which is lost when the GCUs fail.