Alternating Current (AC) - Alternating Current is an electric current that reverses direction at regular intervals (50 times per second in 50 Hz or 60 times per second in 60 Hz).
Anode - An anode is the positive end of a diode or an anode is the positive end of a rectifier.
Blocking Rectifier - A blocking rectifier permits direct current flow in only one direction.
Bolted - A bolted device uses a bolt to hold two or more parts together.
Bridge - A bridge is a circuit that is used to measure small quantities of current, voltage, or resistance.
Bridge Rectifier - A bridge rectifier is a circuit that is used to change alternating current (AC) to direct current (DC).
Buildup - A buildup is a gradual increase in voltage.
Cathode - A cathode is the negative end of a diode or a cathode is the negative end of a rectifier.
Capacitance - Capacitance is the ability to store an electrical charge.
Capacitor - A capacitor is a device that will store an electrical charge.
Circuit Breaker - A circuit breaker is an automatic switch that is used to open a circuit.
Circulating Current - Circulating current is the flow of current between two or more generators that are working in parallel. Circulating current is also the flow of current between two or more generators that are parallel with a utility line.
Conduct - Conducting relates to allowing the flow of current.
Constant Voltage Regulation - Constant Voltage Regulation is one of the two methods of voltage regulation. Constant voltage regulators allow field forcing to the saturation point in order to maintain the line voltage. This allows the engine to be overloaded. On large block load applications, the engine may not recover.
Continuity - Continuity provides a path for current flow.
Control - A control is a device that controls another device. A control is also a circuit that controls a device.
Cross Current Compensation - Cross current compensation is a method that is used for reactive power equalization.
Current Transformer (CT) - A current transformer is used to step down higher line current.
Direct Current (DC) - Direct current is current flow that moves in only one direction in a given circuit.
Damping - Damping refers to decreasing the amplitude of a signal.
De-energized - A de-energized input refers to stopping the current that is going to a component.
Distribution Winding - Distribution windings go from one end of the core to the other end of the core. These windings are arranged in groups that are located in several slots.
Droop - Droop refers to a decrease.
Excitation - Excitation is controlled direct current (DC) that is used to make a magnetic field.
Energized - An energized input refers to activating a device.
Electrostatic Charge - Electrostatic charge is electricity that is caused by induced voltage and stored charge.
Exciter - An exciter supplies direct current (DC) to the field windings of the generator.
Field - A field is a magnetic line of force that surrounds a conductor. This force is caused by current flow in the conductor.
Field Windings - Field windings are many turns of wire that are wrapped around an iron core. When direct current (DC) flows through the field windings, a magnetic field is produced. This magnetic field is comparable to the magnetic field of a bar magnet.
Flashing - Flashing is a process of putting direct current from an external source into the field windings. This process causes the generator to produce an output voltage.
Flux - Flux is magnetic lines of force.
Frequency - Frequency is the number of cycles that are completed in a one second period. The unit of frequency is the Hertz (Hz). One hertz is equal to one cycle per second.
Full-Wave Rectifier - A full-wave rectifier changes the positive phase and the negative phase of alternating current to direct current.
Gain - Gain relates to the ratio of input magnitude to output magnitude.
Gate - A gate is an electronic part of a controlled rectifier (thyristor).
Generate - The production of electricity.
Grounded - A device is grounded by making a connection to ground. A device could also be grounded by making a connection to a component that is connected to ground.
Hertz (Hz) - Hertz is the unit of measurement for frequency. One hertz is equal to one cycle per second.
Humidity - Humidity is the water content that is present in the air.
Impedance - Impedance is the resistance to alternating current.
Impulse Modulation - Impulse modulation changes the following characteristics of a wave: amplitude, frequency and phase. This is accomplished by impressing one wave on another wave that has constant properties.
Induce - This refers to the transfer of power from one device to another device. The transfer is done via a magnetic field or via an electric field.
Interference - Interference is an unwanted mixture of electrical signals. Interference is usually associated with electrical noise.
Instrumentation - Instrumentation is a group of instruments that are used for measuring a system function.
Insulated - An insulated device is a device that is covered with a nonconductive material.
kVA - This is the abbreviation for Kilovolt Amperes. kVA is a term that is used when electrical devices are rated. In order to calculate a device's kVA rating, multiply the rated output (amperes) by the rated operating voltage.
KVAR - This is the abbreviation for Kilovolt Amperes Reactive. KVAR is associated with the reactive power that flows in a power system. Reactive power does not load the generator set's engine. Reactive power will cause thermal loss in the generator.
KVAR Regulation - KVAR Regulation is one of the two methods that are used to regulate the reactive power output. Regardless of the generator's real power output, the voltage regulator causes the generator to produce a constant value of KVAR. In this case, the generator's power factor will change when the generator's real power output changes. KVAR regulation is used when the generator is connected in parallel with an infinite bus (utility) and it is not possible to change the system voltage.
Kilowatts (kW) - Kilowatt is the electrical rating of the generator. One kilowatt equals 1000 watts. Actual power is measured in kilowatts.
Lead - A lead is a wire.
Line Voltage - Line voltage is the output voltage of the generator that is measured between the generator leads (phases).
Lock In - Lock in occurs when a contact closes in order to keep a device in an energized state.
Lock Out - Lockout occurs when a contact opens in order to keep a device in a de-energized state.
Magnetic - A magnetic device is a device that has the characteristics of a magnet.
Magnification - Magnification refers to the enlargement of an item.
Module - A module is an assembly of electronic components and electronic circuits.
Moisture - Moisture is the presence of water.
Oscillation - Oscillation is the flow of electricity that periodically changes direction and/or magnitude.
Permanent Magnet (PM) - A permanent magnet supplies the initial magnetism that is required to start a PMPE generator.
Permanent magnet pilot excited (PMPE) - A PMPE generator receives power for the voltage regulator from a pilot exciter. A PMPE generator consists of a permanent magnet and a pilot exciter.
PF Regulation - PF Regulation is one of the two ways to regulate the reactive power output. PF regulation is used when the generator is connected in parallel with an infinite bus (utility) and it is not possible to control the system voltage.
Phase Winding - A phase winding is a group of generator stator coils. Electric power for one phase of the load is induced in the phase winding.
Polarity - Polarity is the positive characteristics or the negative characteristics of two poles.
Power Factor (PF) - Power factor is the ratio of apparent power (kVA) to total power (kW). The power factor represents the portion of the current that is doing useful work. Power factor is expressed as a decimal number between 0 and 1.
Pulsating - Pulsating relates to the characteristics of current that are similar to mechanical vibration.
Radio Suppression - Radio suppression reduces the amplitude of radio frequency interference.
Reactive Droop Compensation - Reactive Droop Compensation is one of the two methods that are used for reactive power equalization. In reactive droop compensation, the voltage regulator causes an individual generator output to change in proportion to the reactive current. This reactive current is measured with a current transformer.
Reactive Power - Reactive power flows back and forth between the inductive windings of the generator. These windings are part of the electrical load. The reactive power does not perform any useful work in the electrical load. The reactive power only applies load to the generator. This limits the generator's capacity.
Reciprocating - Reciprocating motion is motion that first moves in a straight line in one direction. The direction of this motion then varies by 180 degrees.
Rectifier - A rectifier is a diode circuit that converts alternating current (AC) to direct current (DC).
Regenerative Power - Regenerative power is power that works against primary power.
Reset - A reset returns a switch to a ready condition. In addition, a reset returns a circuit to a ready condition.
Residual Magnetism - Residual magnetism is a small amount of magnetism that is remaining in a device after excitation is removed.
RFA - An RFA is a rotating field assembly.
Rotating Rectifier - A rotating rectifier is mounted to a plate on a generator shaft. This plate then rotates with the generator shaft.
Rotor - A rotor is the rotating windings of a generator.
Saturable Reactor - A saturable reactor has characteristics that are similar to a valve. As the load changes, a valve opens in order to give more current to the output or a valve closes in order to give less current to the output.
Saturated - A device has been saturated when the device has been magnetized in excess. When saturation occurs, a large increase in current results in a small increase in magnetic force.
SCR - An SCR is a silicon controlled rectifier. An SCR is a semiconductor.
SE - An SE generator is a self-excited generator. An SE generator uses a small part of the generator output to provide excitation current back to the generator. An SE generator uses residual magnetic field for start-up.
Semiconductor - A semiconductor is a component such as one of the following components:a transistor, a diode and a thyristor. Semiconductors have electrical characteristics that are between a conductor and insulation.
Series Boost - A series boost is an attachment that allows generator output to continue for a short time during a line failure. This allows the circuit breaker to trip in sequence.
Short - A short is an undesired electrical connection that exists between two or more components.
Shutdown - A shutdown occurs when the engine is stopped. This shutdown can occur manually or this shutdown can occur automatically.
Simultaneous - A simultaneous occurrence refers to two actions that happen at the same time.
Solid-State - A solid-state component is an electrical component that has no moving parts.
Stator - A stator is the windings of a generator that do not rotate.
Surge - A surge is a sudden increase in voltage or current.
Tap - A tap is a connection at the midpoint of a circuit. From this tap, power is taken from the circuit.
Transfer - A transfer refers to moving something from one point to another point. A transfer also refers to converting something from one state to another state.
Transient Peak Voltage - A transient peak voltage is a high voltage condition of limited duration.
Turn-on - When a device is turned on, the device is activated or the device is started.
Varistor - A varistor is a device that loses resistance as voltage increases.
Voltage Droop Resistor - A voltage droop resistor is a variable resistor. This resistor is used to control the change of voltage. This can occur when a generator is paralleled with another generator. This can also occur when the generator is paralleled with a utility.
Voltage Level Rheostat - A voltage level rheostat gives a range of control that is used when the voltage output level is adjusted.
Voltage Regulator - A voltage regulator is a circuit that senses the generator's output voltage. The field coil current is automatically adjusted in order to maintain the desired output.
Voltage Spike - A voltage spike is a brief high voltage.
Volts per Hertz Regulation - Under block loading conditions, the Volts per Hertz Regulation provides fast recovery. This regulation maintains close voltage control over the normal load range. This regulation also produces a rapid response of the generator set. This control is maintained by matching the generator output to the engine performance.
Windings - Windings are layers of wire on a core.
Wiring - Wiring relates to the wires of a circuit.
Wound - Wound refers to being circled.