T-44 ELECTRICAL SYSTEMS
 

• Battery: 24 VDC, 34 amp/hour, Ni-Cad, 20 Cell

• Generators (2): 250 amp, 28VDC, mounted on engine accessory section

• Inverters (2): 750 Volt/amp, single phase
• - supplies 26 VAC @ 400Hz for torquemeters
• - 115 VAC @ 400 Hz to AC busses 1 and 2.

• AC bus voltage: 114 (+ - 7) VAC

• Generator Control Boxes:
• 1. Overvoltage protection (28.25 +- .8)
• 2. Automatic Paralleling
• 3. Reverse Current Protection
• 4. Overvoltage Protection (31 VDC)
• 5. Undervoltage Protection (18 VDC)

• Batter Charge System Function Terminates If:
• 1. Battery temperature exceeds 130 deg. F
• 2. Charger Case temp. exceeds 180 deg. F
• 3. An open or shorted battery temperature sensor
• 4. Voltage imbalance of 1 V between 10 cells
• 5. Input bus overvoltage exceeds 29 VDC
 
• APU:
• 1. Does not exceed 28 VDC
• 2. Continuous load of 300 amps
• 3. Bursts up to 1000 amps for 0.1 seconds
 
• Hot Battery Bus:
• Single Powered Items
• 1. L,R fire extinguishers
• 2. Threshold lights
• 3. Baggage door light
• 4. Wing spar light
• 5. Aft compartment light
• 6. Cabin door observer light
• 7. Crossfeed light
• Dual Powered Items
• 1. L. boost pump 1. R. boost pump
• 2. L. firewall valve 2. R. firewall valve
• 3. Crossfeed valve
• [___________________]-#1 fuel bus [__________________] #2 fuel bus
 
• Current Limiters: 325 amp slow blow fuse or "bus tie"
• - connects L and R main busses to batt bus
• - with generator failure, busses receive power from other generator
• - isolate shorts
• If Master Cockpit Circuit Breaker Fails: pull Gyro Instrument CB to restore
 
• Lose AC Power Then You Lose:
• 1. RMI
• 2. HSI
• 3. Vertical Gyro
 
• Lose DC Power Then You Lose:
• 1. AOA system
• 2. Altitude encoder
• 3. Pilot turn and slip
• 4. Radio altimeter
• 5. Same as AC loss
 
• Weights
• Ramp: 9710
• Takeoff: 9650
• Landing: 9168
 
• Compressor Bleed Valve: closing at 62%...closed at 75%

• Autoignition: Ignites plugs if Torque is below 410 +- 50 ft. lbs

• Landing Gear Systems:
• Overcoasting stopped by limit switches and dynamic braking

Squat Switches:

Left: 1. Dump Solenoid 2. Inlet lip heat, 3. Ground max heat 4. Preset Solenoid 5. Ambient air solenoid 6. Cabin door seal

Right 1. Landing Gear Circuit 2. Inlet lip heat, 3. Stall warning 4. AOA indexer 5. Gear handle downlock 6. Flight hour meter