Block 8 Electrical Flashcards
What effects can electric shock have on the body?
Disrupt the body’s normal electrical functions
Can stop the heart
Can stop the lungs
Or both causing severe injury or death.
When does an electrical shock occur?
When a current passes through the human body. The current will flow through the body’s nervous system or vascular system to the ground.
What is voltage and what are the types?
It is the electrical force of current measured in volts (v).
The two types are AC and DC.
What is Alternating Current Voltage?
Voltage that moves in both directions simultaneously. It’s the primary form of voltage used for most systems on the P-8A
What are the AC sources of power?
115 VAC is provided by: IDG's APU Generator External Power Static Inverter.
What is Direct Current Voltage and what is it primarily used for?
It is voltage that flows in one direction.
It’s primarily used for Emergency Backup Systems and systems essential to flight.
What are the DC sources of power?
Batteries and Transformer Rectifier Units.
What is Electrical current and what is it measured in?
It is the movement of electrical charge through a circuit.
It is measured in amperes (amps)
What is Resistance and what is it measured in?
It causes an opposition to the flow of electricity in a circuit.
It is measured in ohms. ,,
State Ohm’s Law
The current through a conductor between two points is directly proportional to the voltage across the two points.
I=V/R
What is Frequency and what is it measured in?
It’s the number of complete alterations per second of an AC circuit.
It is measured in Hertz.
What is an Electrical bus?
A central point at which either AC or DC voltage is distributed throughout multiple systems.
What are circuit breakers?
A push pull type, overcurrent protection device that is resettable.
What is a Fuse?
An overcurrent protection device that is for one time use only.
What is a Relay?
An electrically actuated switch used to control the distribution of electricity in a circuit.
What is the purpose of the Electrical Power System?
It generates, supplies, and controls aircraft electrical power. It has manual and automatic control features.
What is External Power?
It is the normal source of AC power for the airplane electrical system when the airplane is on the ground.
It gives power to the battery charge to charge the battery.
What does the two Integrated Drive Generators produce?
Three-phase, 115/200v a.c., 400 Hz power for use by the electrical power system.
What is AC Generation?
A three-phase, four-wire system that operates at 115/200v AC, 400 Hz.
What does IDG1 and IDG2 produce?
115 VAC, 3 phase, 400 Hz rated up to 180 mva or 522 amps.
What does the APU Starter Generator supply?
115 Vac, 3 phase, 400 Hz rated up to 90 mva or 261 amps below 32,000 ft and 66kVA at 41,000 ft.
What does DC Generation supply?
A nominal 28v dc to different loads.
What’s the purpose of the Main Battery?
It is a 48 ampere-hour, nominal 24 VDC power source that supplies power for APU starting and is a standby source if all other power sources does not operate.
How long will the Main and Auxiliary Batteries provide power after loss of all AC power?
30 minutes
What’s the purpose of the Auxiliary Battery?
It is a 48 ampere-hour, nominal 24 VDC power source that helps the Main Battery supply standby power
What’s the purpose of the Transformer Rectifier Units (TRUs)?
They receive 115 VAC, 400Hz electrical power and convert it to provide a nominal 28 VDC to airplane systems that require DC power.
How many Mission Transformer Rectifier Units are there?
8
What does the Standby Power system supply?
A nominal 28 VDC and single phase 115 VAC, 400 Hz to electrical bus which must have power to maintain safe flight when AC power is not available.
What is the Secondary Power Distribution System.
It’s a semi-automated, remotely controlled electrical power distribution system.
