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Jargon Buster

Power Generation

When entering into any new industry there will be terms, words and abreviations that do not make an awful lot of sense and the power generation sector makes no exception. That’s why FW Power have created a Jardgon Buster, to put all that uncertainty to rest.  Below is a list from A-Z of terms commonly used in the power generation sector.



Ac Generator:  Electrical generator that produces alternating current (correct term).

Active power: AC power with a unity power factor. measured in Watts.

Air circuit breaker: Circuit breaker using air as the arc extinguishing media (ACB). See also Circuit breaker.

Alternator: Electrical generator that produces alternating current (non-preferred, obsolete term)

Analogue controls Controls using variable voltage or current to pass information.

Apparent power: The product of current and voltage in an alternating current circuit which has a reactive element.

Arc flash:  Arc Flash is the result of a rapid release of energy due to an arcing fault between a conductor and another conductor or neutral or a ground. During an arc fault the air is the conductor. Arc faults are generally limited to systems where the bus voltage is in excess of 120 volts. Lower voltage levels normally will not sustain an arc. An arc fault is similar to the arc obtained during electric welding and the fault has to be manually started by something creating the path of conduction or a failure such as a breakdown in insulation.

Armature: The assembly of windings and iron core in which the generator output is produced. Sometimes referred to as the Stator to avoid confusion.

Asynchronous: Term applied to motors or generators which operate at a speed not fixed by poleage and the supply frequency. (i.e. an induction generator or induction motor). (See Slip).

ATEX:   ATEX is an acronym for a series of EU Directives describing what equipment and work environment is allowed in an environment with an explosive atmosphere. The ATEX 137 workplace directive 99/92/EC has been enacted in the UK as DSEAR. The term ATEX has been derived from the French: Atmospheriques Explosives.

Attenuators:  Devices for reduction of the emission of sound.

Auto transformer starter: Transformer switching arrangement to reduce voltage applied to an electric motor during starting.

Automatic mains failure: Referring to the duty of a generating set to start and take over the load on indication of mains electricity failure. Also often referring to the build of control panel used, e.g. AMF Panel.

Automatic Transfer Switch (ATS): A device used to automatically switch a power supply from normal to emergency when a power failure occurs (ATS).

Automatic voltage regulator: Device used to control the voltage of an ac generator by sensing the terminal voltage and varying the field current.

Auto transformer starter:  Transformer switching arrangement to reduce voltage applied to an electric motor during starting.

AVR droop: AVR voltage reference is reduced as VAr increases.

Backup protection:  Type of protection intended to operate only after the main protective device(s) has failed to operate.

Base load: The portion of load of a generator or building which is constant. Alternatively referring to a constant generator output when in parallel with the grid.

Bedplate: Metal fabricated structure to support the engine, generator, radiator etc. of a generating set or other plant. Also known as a baseplate.

Berm:  Ridge or embankment separating two areas. Often used alongside rivers as flood prevention. Also used around sites to provide visual and noise separation. A continuous berm enclosing an area is a bund.

Biodiesel:  Diesel fuel with all or part content derived from vegetable and / or animal oils.

Black start: Refers to starting of a power system without the use of an external power source (but internal power such as dc control and start power is available).