Diesel Generator Frequently Used Industry Terms


AC Generator

Electrical generator that creates alternating current

Active Power

AC power including a unity power factor, this is measured in Watts.

Air Circuit Breaker

A circuit breaker that uses air as the acrc extinguishing media (ACB) See Circuit Breaker.


An Electrical Generator that creates an alternating current.

Amortisseur Winding

View: Damper Winding

Analogue Controls

Controls that use a variable voltage or current to pass information.

Apparent Power

The result of current and voltage inside an alternating circuit which has a reactive element.

Apparent Power

The result of current and voltage inside an alternating circuit which has a reactive element.

Arc Flash

An Arc-Flash is created by the super-quick release of energy due to an arcing fault between a conductor & another conductor, neutral or a ground. When an arc fault occurs the air is the conductor. Arc faults are typically limited to systems where the bus voltage exceeds 20 volts. Lower voltage levels typically don't sustain an arc. An arc fault is like an arc created during electric welding & the fault has to be manually started by something creating the path of conduction or a failure like a breakdown in the insulation.


The assembly of winding's and iron core in which the generator output is produced.Sometimes referred to as the Startor to avoid confusion.


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


A set of European Directives explaining what equipment and working environment is permitted within an explosive atmosphere. ATEX is an acronym derived from the French: Atmospheriques Explosives.


Reduce the emissions of sound from within a diesel generator enclosure.

Auto Transfer Starter

A transformer switching set to keep a reduced level of voltage being applied to a motor during start up.

Automatic Mains Failure

This is when the generator takes over the power supply from the main supply in the event of a power cut or power outage.

Automatic Transfer Switch

A device that can be attached to a generator to make the genset kick into action when the supply from the main grid drops due to a power cut or power outage. The device is commonly know as an ATS Switch and can be purchased and added to your set here at Diesel Generator Direct.

Automatic Voltage Regulator

Used to control and maintain the constant voltage of an AC generator. It works by sensing the terminal voltage and altering the field current.

Automatic Transfer Starter

A transformer switching configuration that will reduce the voltage being applied to an electrical motor during the startup process.

AVR Droop

as VAr increases the AVR voltage is reduced.


Backup Protection

A fail-safe to kick into action only after the main protective device(s) have failed to work.

Base Load

The portion of load a generator delivers which is consistent. Its is also the lowest level of output a genset can produce without shutting down. The base load can refer to this or the base load of power a client requires to power their operation.

Bed Plate

On a generator set the bed plate sometimes refereed to as a base plate is a metal fabricated structure where the other elements of the diesel generator set sit on top of; the engine, generator, control panel and radiator


A 'berm' is a level area such as a shelf or a raised barrier usually made from soil which has been compressed to separate two areas. Berms are often used along the side of a river as a form of flood protection, they can also be used to provide visual and noise separation, when there is a non-stop berm surrounding an area it is then called a bund.

Bio Diesel

Biodiesel is a fuel which is made-up wholly or partially from derived from vegetable and/or vegetable animal oils.

Black Start

The term Black Start refers to starting up a power system with an internal power supply such as DC control or start power rather than using an external power source

Brown Out

Brownouts can be caused by an overloaded power grid or bad weather (just like a blackout) The term brownout is used to explain a drop in voltage from an electrical power supply system which could have been caused either on purpose or unintentionally. Bad weather and overloaded grids can cause an unintentional brownout, an Intentional brownout on the other hand could be used to reduce the load in an emergency situation. Where a blackout is a total interruption of power in a particular region, a brownout is a temporary, partial reduction in system voltage or total system capacity.

Bulk Tank (Bulk Fuel Tank)

An extra tank can be fitted to your generator where it will extract its immediate supply of fuel. Normally the bulk tank is usually the receiving tank for any fresh supply of fuel. The bulk tank could be used to supply a supply a supply to a day tank, then to the generator set.


a bund ,bunding or a bund wall is a structure that is built around a group of tanks, the purpose of the bunding is to contain any potential leakages to a confined area and halt the spread of the substance.


Bunding, which can also be refereed to as a bund wall is a construction retaining wall or bank around storage. More often than not they are seen around large tank farms, but they can be used around smaller sized tanks too. Smaller tanks can have integral bunds, often called twin skin or twin wall tanks or "self bunded tanks". The bunding of generator fuel tanks is usually needed for tanks that volume exceeds 200 litres. Containerised generator sets (gensets) are often bunded by the sealing of the containers floor.


Normally rigid, aluminium or copper conductors that inter-connect high current circuits in a switchboard or building.


Check Synchroniser

A device that checks that the automatic or manual synchronisation which is used to match the voltage magnitude, frequency and zero crossing times (phase) of two power sources to ensure that they are connected in parralel.


An electrical circuit is a path in which electrons from a voltage or current source flow therefore the path must be a closed loop. Usually a circuit is made up of electrical elements such as resistors, inductors, capacitors, transmission lines and switches the signal chain must derive from a power source and return a closed loop for the current to expell.

Circuit Breaker

A generator circuit breaker is a protective device that breaks the flow of current within a circuit when the level reaches a threshold.

Close Fit

This is a term we use at generator direct to describe the tight surrounding of a sound treated canpoy on a generator, the compact build of these canopies allows for reduced footprint and sound attenuation.



Hygroscopy is when a substance attracts and holds water molecules from the surrounding environment via. This is achieved through either absorption where the water enters the substance or adsorption where the water molecules sit on the surface in a film (like when we see oils on the surface of a pond). Hygroscopy can change the dynamic of the substance in volume, boiling point, viscosity, or other physical characteristic or property of the substance, as water molecules can become suspended between the substance's molecules in the process.












Sub-Sea Cable

A Sub-Sea Cable otherwise known as Submarine Power Cable is a transmission cable that passes electricity through the cable below the surface of a sea, lake or ocean, these cables are able to pass the electricity beneath salt and fresh water bodies.