Ch 3 & 4 Flashcards
3 major Battery Hazards?
Burns
Electrical Shock
Explosive Gas
5 battery safety precautions?
Vent fans in battery bank Operators alert No open flames Shower or eyewash available Protective Clothing
Conductor loop turning in a magnetic field cutting across magnetic lines of force.
Simple Generator
Result of one side of the generator loop cutting across the lines of force in one direction and the other side of the loop in the opposite direction.
1st half turn = positive voltage
2nd half turn = negative voltage
One whole turn is AC generation
Sine-wave Output
Component used to drive AC generator.
Prime Mover
Rotating part Of AC generator that is driven by the prime mover.
Rotor
Stationary part of AC generator
Stator
Electrical connections used to transfer power to/from the rotor of an AC generator.
Slip Rings and Brushes
Controls the field current to regulate output voltage from generator.
Voltage Regulator
Number of cycles of an AC voltage/current that occur in 1 second.
Measured in Hertz Hz
Frequency
Amount of time it takes to complete one cycle.
Period
Amount of AC that produces same heating effect as an equal amount of DC.
Effective Value of AC
A 3-phase waveform consists of…
3 single phase sine-waves, equal in magnitude and 120 degrees apart.
Why are 3 phase power systems used?
3 phase circuits weigh less than single phase circuits.
Wide range of voltages and can be used for single phase loads.
3 phase equipment is smaller, weighs less and is more efficient than single phase.
Developed through interactions with rotor and rotating magnetic field.
Torque in AC Motor
Slip increases from 0 to 10%, torque increases linearly. Torque will reach a max value at 25% slip. If passed it will stall.
AC Induction Motor
Starting Current in AC motor: current caused by what?
Power required to build up rotating field in the motor.
Interactions between rotor currents and stator magnetic fields.
Extra energy required to overcome inertia of machine.
Motor current during operation varies directly with what?
Motor Load
Chemical/voltaic cell has two electrodes of different types of metals and an electrolyte solution.
Battery
Electrical conductors that are used to make contact w nonmetallic part of a circuit.
Electrodes
Consists of two or more chemical voltaic cells connected together.
Battery
Ratio comparing weight of any liquid to the weight of an equal volume of water.
Specific Gravity
Specific gravity for this in a battery is 1.275
Electrolyte
Current of 1 ampere flowing for 1 hour
Ampere-hour
Difference between synchronous speed and rotor speed.
Slip
Converts chemical energy to electrical energy.
Battery
Magnetic Induction - Holy Trinity
Conductor, magnetic field, movement.
What goes up when charging a battery, down when discharging?
Specific gravity and voltage
Sine Wave Values
Peak value - highest pt
Effective value - peak value x .707
Instantaneous Value - Current value
Consists of conductors within generator that receive voltage from a DC source and produce mag flux.
Field
The part of the AC generator that produces voltage.
Armature
Conductor carrying current in a magnetic field.
Torque
