NATOPS Chapter 2 Electrical and Lights HSM-50 Flashcards
AC power generators/APU
DC power converters
Battery power
30/45 kVA (35 kVA for APU), 115-volt AC, 3 phase, 400 hz
28 volt dc
24 volt dc, 5.5 amp
GCU is/does what?
Generator control unit
- Connects generator to AC bus system
- regulates generator output
Protects against:
-overvoltage, undervoltage, feeder fault, underfrequency
When does the GCU remove the generators from the bus system?
Ground: below 94% NR
Air: below 80% NR, reconnects above 97% NR
External power is monitored for:
- phase rotation
- overvoltage
- undervoltage
- over frequency
- under frequency
Includes a 4 amp circuit breaker with a 2 amp draw so that the ship can sense the load to provide power.
What are the 5 ac electrical buses?
1 and #2 AC Primary
AC essential
AC secondary
AC Monitor bus
The No. 1 generator normally power the :
1 AC primary
AC Essential
AC Secondary
The No. 2 generator normally powers the :
#2 AC primary AC Monitor bus
If both generators are on the APU is?
Not connected
If electrical power demand exceeds the capacity of the generator operating normally, the electrical bus loads are redistributed to available generators as follows:
aka Three little pigs
- Backup pump, will always be powered if required (#1 AC primary bus)
- Mission power is the next priority (AC Secondary bus). Bus also has tail rotor deice
- Main rotor deice has lowest priority (AC Monitor bus)
Ext pwr is automatically removed when ____________
APU or main generator is brought online
With ______ charge the battery will last _____ at night and _____ at during the day
80%
9min
11min
What are the D.C. Buses?
No. 1 and No. 2 DC primary bus
D.C. Essential bus
Battery utility bus
Battery bus
If only on battery power; the DC essential bus will get dropped at _______
35% charge
The battery utility bus receives power from the ________
Battery regardless of position.
Will connect to the dc essential and battery bus if in the ON position and battery is the only source of power.
With no other source of DC power, and battery below _____ the power may be insufficient to do what?
30%
Blow the fire extinguisher CADs
The batt low charge appears at ____
40% power
Battery fault caution means that the ______
Battery has an overtemperature or cell dissimilarity. Battery is disconnected from the charging circuit.