Electrical System Flashcards
What is the AC Generator load rating?
Rated at 75 KVA for continuous operation and 90 KVA for emergency operation
Produces 115 V / 200 A at 420 Hz
What type of battery is utilized
24 volt, Nickel-cadmium 15 amp hour rating
What would cause a BATT HOT caution segment to illuminate?
What action is required by the Pilot?
What temperature will it extinguish?
When the battery internal temperature is above 158 - 160 F (70º C).
No pilot action required. The battery is automatically disconnected from the charging circuit until internal temp drops
The Caution light goes out when the internal temperature drops below 63°C +/- 2°
How would the DC electrical system be affected if the #1 DC converter were to fail?
No affect- The internal interconnections within the DC distribution unit automatically restore power to the failed busses without pilot intervention.
Can you recharge the battery with a dual converter failure?
NO – Since both DC Primary Busses are dead.
What would happen if both DC converters fail?
The Backup Converter would then power the DC Essential Bus and Battery Bus. The battery would power the Battery Holdup and Utility Busses.
With a loss of both AC Generators, can the APU generator power the entire Electrical load? If not, what equipment will be lost?
The APU is not able to carry the entire load and will auto shed the following equipment, acronym WARMAir
Pilot and copilot windshield anti-ice (pilot side recoverable by placing the pilot windshield anti-ice switch to OVRD)
AVC system
Main and tail rotor blade deice (RIPS) (droop stop heaters continue to be powered)
No 1 Engine anti-ice mat
Air-conditioning system
What is the APU AC Generator load rating?
35 Kva, 45 Kva for 5 minutes
Explain the function of the GCU?
Each AC Generator has a dedicated GCU
Regulates and monitors output for over voltage and under voltage, feeder fault (overcurrent) and under-frequency conditions.
Under frequency protection is disabled when the helicopter is off the ground (weight off wheels)
How are the Main generators and the APU generator cooled?
Main generators- Oil cooled by the main transmission oil through the accessory modules
APU generator- Air cooled
How is DC electrical power produced?
2 main 400 Amp regulated DC converters
1 back up 125 Amp unregulated DC converter
After a dual DC converter failure, the back up converter and battery will power what busses?
DC Essential
Battery
Batt Utility
Batt Holdup
What equipment in the cockpit is powered after a Dual DC converter failure?
DC Essential
Battery Bus
R/H pilots PFD & MFD
#1 RTU
#2 AHRS
