Glossary of Terms

We have compiled a list of commonly used terms for used diesel generators and surplus diesel generators.
We hope you find this information useful and if you have any questions give us a call at 208-262-9875.

Vital Power & Equipment your home for generators.  We sell Used Generators and New Surplus Generators.  Diesel and Natural Gas Generators. Emergency Standby and Portable Generators.

GLOSSARY OF COMMONLY USED GENERATOR PARTS AND TERMS

[A]

 

  • Alternating Current (AC)
    • An electric current which changes direction with a regular frequency

 

 

  • Alternator
    • An electric generator that produces an alternating current, which uses rotating parts to change the magnetic field to the alternating current.

 

 

  • Ambient Temperature:
    • The surrounding air temperature of the diesel generator in any giving area

 

 

  • Amperage
    • Is the strength (intensity) of an electrical current, which is measured in amperes, commonly referred to as (AMPS)

 

 

  • Ampere
    • Named after the French physicist Andre M. Ampere.  An ampere is a type of electric current produced by one volt applied across a resistance of one ohm.

 

 

  • Apparent Power
    • Measured in “volt amperes” and is often express in “kilovolt amperes” (kVA).  It is the product of voltage, (volts) and the current (amperes), it is both active and reactive power.

[B]

 

  • Backup Generator or Genset
    • A generator used as emergency power back up.  The best line of defense for a power outage.

 

 

  • Battery
    • Is a group of usually two or more cells that are connected together to provide an electrical current.

 

 

  • Battery Charger
    • A generator battery charger is different than the battery charger in your vehicle.  A generator battery charger is designed to maintain and supply a constant float voltage to the battery to optimize the life of the battery.

 

 

  • Battery Charge Rectifier
    • The rectifier converts AC voltage to DC voltage to charge the battery.

 

 

  • Blackout
    • Refers to the sudden loss of all electrical power.

 

 

  • Black Start
    • This refers to the starting of the generator by way of its own power source with out any external power supply.

 

 

  • Brownout
    • Is the commonly used term in the industry, which refers to the reduction of voltage or power when the demand for the electricity exceeds capacity.

 

 

  • Brush
    • Consists of either graphite or copper conducting elements, which maintains the sliding electrical contact between the static and moving element.

[C]

 

  • Commutator
    • Is a device used in a generator to convert or “switch” the alternating current that the generator produces into a direct current before the current is sent to an external circuit.

 

 

  • Contactor
    • A device that uses a small control current to energize or de-energize the load.  The contactor is designed to handle high amounts of current and are combined with overload relays
  • Core
    • Is comprised of laminations in the generator that constitute the magnetic structure.

 

 

  • Cradle
    • Is often revered to the metal frame or cover enclosing the generator or engine, to provide protection from external interferences.

 

 

  • Current
    • The rate that electricity flow

[D]

 

 

 

  • DC Generator
    • A generator that transforms mechanical energy into D-C electric energy

 

 

  • Decibel Level (DB)
    • Used in the industry to define noise level

 

 

  • Delta Connection
    • Delta connection is a three-phase connection where the beginning of each phase is connected to the end of the next phase.

 

 

 

 

  • Diode
    • It is an electrical component with two active terminals called an anode and a cathode.  It allows the current to pass in only one direction.  In addition it converts AC power to DC power.

 

 

  • Direct Current
    • Is an electrical current that flows only in one direction.

 

 

  • Dynamo
    • Is simply an electric generator that produces a direct current.

 

 

[E]

 

  •  Emergency Power
    • Commonly referred to as the “generator”.  Emergency power is needed when there is a loss of electricity to a building or facility.  The generator(s) supplies the “emergency power” to maintain operations which could potentially save companies millions of dollars and save the lives of those involved with a power outage, for example the patients and personnel in a hospital.

 

 

  • Enclosure (AKA Housing)
    • There are two common types of enclosures

1)    Sound Attenuated – A sound attenuated enclosure or is an enclosure that is baffled or insulated to reduce the noise made from the generator.

 

2)    Weather Enclosure – A metal enclosure that is not sound- proofed but is used to keep the outside elements from interfering with the normal operations of the generator.

 

 

 

  • Exciter
    • Is known as an auxiliary generator, that provides power or electrical current to a larger generator.

 

 

[F]

 

 

 

  • Frequency
    • Is the number of complete cycles of the alternating voltage per second.  Typically referred to as hertz (Hz)

 

 

  • Frequency Regulation
    • Measures the difference between a non-load and a full-load frequency as a percentage of the full-load frequency.

 

 

  • Fuel Cell
    • A non-combustible device that converts the energy of a fuel to electricity or heat.

 

 

  • Full Load
    • Is the maximum load of a generator of circuit.  Any additional load would be considered an overload.

[G]

 

 

 

  • Generator
    • A machine that converts mechanical energy into electrical energy.

 

 

  • Genset
    • A commonly used term for generator (see Generator)

 

 

  • Green Energy
    • Is the production of electricity from renewable resource such as solar, wind and geothermal. Green electricity is non-polluting.

 

 

  • Grid
    • The Commercial Utility’s electrical system used for supplying power.

[H]

 

 

 

  • Hertz (Hz)
    • Cycles per second commonly referred to as frequency.  North America runs 60 Hz.

[I]

 

 

 

  • Idle Control
    • A device that the controls the idle speed of an engine in direct relation to an electrical load.

 

 

  • Ignition Coil
    • The ignition coil is device that supplies DC voltage to the spark plugs.

 

 

  • Inrush Current
    • Is the immediate input current by a power supply when it is first turned on.

 

 

  • Insulation
    • The non-conductive material used to prevent the escape of the electric current from a conductor.

 

 

  • Inverter
    • Changes DC power to AC power. Also known as a power converter.

[K]

 

 

 

  • Kilo-volt-amperes (kVA)
    • kVA is an electrical term used to rate electrical devices. 1,000 Volt Amperes.

 

 

  • Kilowatt (kW)
    • An alternate term for rating electrical devices. 1,000 watts

 

 

[L]

 

 

 

  • Leg
    • Is the phase winding of a generator.

 

 

  • Load
    • Is the amount of electric power that various devices demand from the electricity generator system.

 

 

  • Load Factor
    • The ratio derived from the average load to the generator power rating.

[M]

 

 

 

  • Main Breaker
    • Is the main circuit breaker at either the input or output of the bus, of which all the bus power must flow.

 

 

  • Manual Bypass Switch
    • Is a switch that is manually operated to bypass electrical components in an Uninterruptible Power Supply (UPS), so work can be done with out power interruption.

 

 

  • Megawatt (MW)
    • One million watts of power or electricity.

[N]

 

 

 

  • N.E.C
    • National Electrical Code (NEC)

 

 

  • N.E.C.A
    • Is the National Electrical Contractors Association. (NECA)

 

 

  • N.E.M.A
    • Is the National Electrical manufactures Association (NEMA)
  • Natural Gas Generator:  A generator that runs on Natural Gas and/or Propane
  • Used Natural Gas Generators:  A used natural gas generator can save our clients time and a lot of money.

[O]

 

 

 

  • Ohm
    • Is a unit of electrical resistance.

 

 

  • Ohmmeter
    • Is the device used to measure electrical reistance.

 

 

  • On Set Paralleling
    • Manuel paralleling systems that is built onto the generator.

 

 

  • Overcrank
    • A feature with most generators that displays an alarm when the generator fails to start.

 

 

[P]

 

  • Power Distribution Unit (PDU)
    • A device that monitors and controls the distribution of power to other loads.

 

 

  • Peak Load
    • Is the maximum kW demand of a facility.

 

 

  • Peak Shaving
    • Is when a facility reduces it’s electrical demand from the utility by using the back up generator during high demand times.

 

 

  • Power Factor
    • The ratio between the real power, kW and the apparent power, kVA in a circuit.  The standard power factor is shown as a percentage (.8) or 80%.

 

 

[R]

 

 

 

  • Reactive Power
    • Is the energy movement in an Alternating Current (AC) arising from the production of electric and magnetic fields.

 

 

  • Rectifier
    • Is and electrical device that converts AC power to DC power.

 

 

  • Rotor
    • Is the rotating element of a generator or motor.

 

 

  • RPM
    • Is Revolutions Per Minute (RPM)

[S]

 

 

 

  • Single Phase
    • Is an Alternating Current having two input terminals and two output terminals.  Single phase is often referred to as 110/220 volt or120/240 volt.

 

 

  • Stator
    • Is the stationary part of a generator or motor.  The direct opposite of a Rotor (see rotor)

 

 

  • Surge
    • A sudden variation in frequency, current or voltage

 

 

  • Synchronized
    • The matching of one wave to the other by adjusting the phase angle and frequency until the two coincide.

 

 

 

 

  • Synchronous Generator
    • Is an AC generator having a DC exciter.

[T]

 

 

 

  • Tachometer
    • An instrument that measures rotational speeds of a shaft or disk, usually displayed as RPM’s.

 

 

  • Transfer Switch
    • Transfers the load from the original source, usually the utility, to the back up generator if the original source has failed.

 

 

  • Transformer
    • A device commonly used to decrease or increase the voltage from the generator to match the facilities voltage.

[U]

 

 

 

  • Underwriters Laboratories (UL listed)
    • A non-profit, independent testing and certification organization.

 

 

  • Utility
    • Your commercial power source.  Your local “Utility” company.

 

  • Used Diesel Generators

A good used diesel generator can save our clients time and a lot of money.

 

 

[V]

 

 

 

  •      VITAL POWER AND EQUIPMENT
    • Your #1 on source for high quality used diesel generators and natural gas generators.

 

 

[W]

  • Watt
    • The unit used for measuring the true total electric power.

 

 

  • Winding
    • Represents all the coils of a generator.