Glossary terms beginning with F

Terms used within Transpower
Click one of the letters above to go to the page of all terms beginning with that letter.
failure mechanism

The physical, chemical or other process which results in a failure.

failure mode

The effect by which a failure is observed, for example an open-circuit condition.

FALM

Term which defines a building fire alarm system indicator panel and includes the components and systems connected to the indicator panel, being heat, smoke and flame detectors, very early smoke detection apparatus (VESDA), manual call points, sounders, bells, alarm lights, mimic and subsidiary panels and alarm signalling equipment for both remote and local alarms.

fault (electrical)

A general term to describe an electrical equipment failure, generally leading to an outage.  It implies either a short circuit, an open circuit, or an earth fault in equipment. See also permanent fault; transient fault; phase-to-phase fault.

fault clearance

The action of a circuit-breaker tripping to de-energise equipment subject to a fault.

fault current

Current flowing in a circuit as the result of an earth fault or a phase-to-phase fault.

fault number

An authority number issued by the service centre or area operating centre which identifies faults for the invoicing of unscheduled work.

fault repair

Fault response, initial investigation, and emergency temporary repairs initiated by a Callout.

fault thrower

An earth switch which will be closed by local protection equipment onto an energised circuit under some fault conditions, thereby causing a remote protection-initiated tripping of the circuit-breaker(s) controlling that circuit.

FAVS

Term used in TP.MS 40.08 to define a ventilation system consisting of the following major components: air intakes, filters, fans, connected ductwork and components, dampers, air diffusion equipment, electrical connections, power supplies, distribution boards and control systems.

FCB

A circuit-breaker in the main field excitation supply of an alternator or synchronous condenser.

feeder

A circuit which provides a direct connection to a customer.

feeder circuit-breaker

A circuit-breaker, usually at the point of connection of the feeder, which can interrupt supply to the feeder.

feeder disconnector

A disconnector  used to isolate a feeder from the grid.

feeder transformer

A transformer located in a local network and directly connected to a Transpower feeder circuit-breaker.  The Transpower circuit-breaker is the HV circuit-breaker for the feeder transformer.

feeders

High voltage cables connecting a circuit breaker at a main substation to one or more secondary substations.

ferrite ring

Inductance device in bypass valve cathode circuit.

FEXT

Term used in this standard to define portable and fixed, hand operated fire fighting equipment for use in buildings.  The term not only includes water, carbon dioxide, foam and dry powder fire extinguishers but fire hose reels, internal fire hydrants, fire service hose and nozzles.

FHC conductor

Flexible hollow-core conductor.

fibre optic cable

A cable containing one or more optical fibres used for communications.

fibre optic termination enclosure

An enclosure inside an optical repeater building or terminal station where optical fibre is jointed to optical pigtails and connectors.

Fibre optic transmission system

Fibre optic transmission system, i.e. the electronic equipment that utilises the OPGW including multiplexing equipment, supervisory management system, d.c. power supply and other ancillary equipment.

field circuit-breaker

A circuit-breaker in the main field excitation supply of an alternator or synchronous condenser.

field support planner

A Transpower employee who liaises with connected parties on commissioning activities and obtains their agreement to the proposed work.

file

A collection of hard copy documents located within one physical hard copy file or folder (e.g. Codafile, lever arch etc.)

file ID

An alpha/numeric code/number/identifier that is located on the file.

file title

The summarised description of the physical file/folder/document content.

filename

An alpha/numeric name applied to the file.

filepath

Route to file location via folders within a directory structure.

filters (compressors)

Devices for separating and removing dust and dirt from the air before it enters a compressor or space.

filtration

A process which removes fine solids and some free water from insulating oil by filter press or cartridge filter.

final voltage

The prescribed level at the battery terminals at which a discharge is considered finished. Discharging the battery beyond this point may result in damage to the battery.

fire alarm system

Term which defines a building fire alarm system indicator panel and includes the components and systems connected to the indicator panel, being heat, smoke and flame detectors, very early smoke detection apparatus (VESDA), manual call points, sounders, bells, alarm lights, mimic and subsidiary panels and alarm signalling equipment for both remote and local alarms.

fire extinguisher system

Term used in this standard to define portable and fixed, hand operated fire fighting equipment for use in buildings.  The term not only includes water, carbon dioxide, foam and dry powder fire extinguishers but fire hose reels, internal fire hydrants, fire service hose and nozzles.

fire sprinkler system

Term used to define a spray or sprinkler system connected to a water supply and includes all system types such as sprinklers, pre-action sprinklers, spray systems, drench systems and deluge systems, including all water supply pumps both diesel and electric and water supply tanks and piped water supplies from connection point to the site water supply.  The system includes alarm signalling equipment for both remote and local alarms.

firm capacity

Power capacity intended to be available at all times during the period covered by a guaranteed commitment to deliver, even under adverse conditions.

first grade power supply

Term used in this standard to identify the secure 415 V power supplies to the Haywards Pole 1 mercury arc valve converters that are provided by auxiliary generators on condensers C7 to C10.

fixed fire detection equipment

Smoke and heat sensing equipment permanently installed at a station to warn of the presence of a fire.

fixed fire extinguishing equipment

Fire fighting equipment permanently installed at a station, for example hydrants, hose reels and sprinklers.

fixed portion

That part of a metal-clad switchboard, incorporating primary connections, secondary wiring and control circuits, into which the circuit-breaker truck is inserted.

fixed switchgear

Metal-clad switchgear in which the circuit interruption mechanism cannot be withdrawn from the circuit/busbar connections to expose spouts.

flag

A visible indicator, usually associated with a protection scheme to indicate that a relay has operated.  Most relays have flags  (which on modern relays may be an LED or a similar device).

flagging sheet

A sheet used for recording protection flag operations.

float voltage

The minimum constant potential necessary to offset the internal losses of the battery.

floors of a building

The standard terms within Transpower are: ground floor, first floor above ground, second floor above ground etc.

fluoride power

A greyish toxic and acidic by product of the decomposition of SF6 gas due to arcing.

folder

File repository within a directory structure.

follow current

The power frequency current which flows through an arrester following the passage of discharge current.

forced air ventilation system

Term used in TP.MS 40.08 to define a ventilation system consisting of the following major components: air intakes, filters, fans, connected ductwork and components, dampers, air diffusion equipment, electrical connections, power supplies, distribution boards and control systems.

forced interruption

An interruption caused by a forced outage.

forced outage

The automatic or urgent removal from service of an item of equipment.

FOTS

Fibre optic transmission system, i.e. the electronic equipment that utilises the OPGW including multiplexing equipment, supervisory management system, d.c. power supply and other ancillary equipment.

frequency (power)

Rate of cyclic change in value of current and voltage, quantified by the international standard term "Hertz" (Hz).

frequency control

Adjustment of power generation to maintain system frequency  close to the target frequency.

frequency control reserves

Extra capacity required to maintain frequency on the grid between 49.75 and 50.25 Hz. Provided by one or more generating stations operating in a partly-loaded mode so it can increase or decrease its output, as required, to maintain the frequency within limits for small changes in load. Larger changes in load are managed by dispatching a larger block of generation to the grid.

frequency excursion

A variation of the power system frequency above 50.25 Hz or below 49.75 Hz.

frequency regulating reserve

The spare synchronised capacity available to be used to control the frequency within the normal limits of 49.8 to 50.2 Hz, the response time being sufficiently fast to control the frequency within the normal limits for small changes in demand.

frequency stabilisation

A fast acting but temporary control which stabilises the a.c. frequency in either island by modulating the HVDC power transfer with in a +/-250MW range.  Normally enabled.

frequency time

The time kept by a synchronous clock.

frequency-keeping station

A generating station maintaining frequency control.

frequented location

Any urban area associated with a city or town other than a special location.

fretting/ flogging

The eroding of metal surfaces in contact with each other through constant chafing/ knocking while under load.  This often occurs at bolts and bolt holes on structures subjected to wind stresses.

FSPR,

Term used to define a spray or sprinkler system connected to a water supply and includes all system types such as sprinklers, pre-action sprinklers, spray systems, drench systems and deluge systems, including all water supply pumps both diesel and electric and water supply tanks and piped water supplies from connection point to the site water supply.  The system includes alarm signalling equipment for both remote and local alarms.

functional unit

A part of metalclad switchgear and controlgear comprising all components of the main circuits and auxiliary circuits that contributes to the fulfilment of the function, which they are intended, for example: incomer, feeder, bus-section, etc.

functionality

The constructability, maintainability, and operability of a substation design.