Natare Terminology

Electrical Systems & Control

a b c d e f g h i j k l m n o p q r s t u v w x y z


  • American Wire Gauge (AWG)

    standard system in the United States for designating wire size (diameter of metal)

  • ampere (amp)

    unit of measurement for the rate of electrical current flow; one ampere is the current flowing thorough one ohm of resistance at one volt potential

  • ampere/hour (AH)

  • annunciator

    audible and/or visual signaling device

  • arc

    electrical current through air or across the surface of an insulator associated with high voltage; usually occurs when a contact is opened, de-energizing an inductive load; arcing of a contact will limit its life

  • automatic surge

    device incorporated into a stainless steel perimeter

  • authorized release device

    device that allows authorized persons to enter or exit monitored and controlled openings without triggering an alarm; the authorized passage release may be a keyed switch, a card reader, a digital code reader

  • access control

    means of influencing and regulating flow of persons through a door, entry and/or exit alarm

  • adjustable

    ability to change or alter time delay or other parameter by means of adjustment, such as a potentiometer, resistor, or switch

  • airtraps

    see interlock

  • alternating current (AC)

    electric current that reverses its direction regularly and continually; the voltage alternates its polarity and direction of current flow negative to positive

  • American Society for Testing Materials (ASTM)

    organization that tests materials and attempts to set standards on various materials for industry

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  • Bather Load

    number of people in a pool or spa at a particular time or during a specific period of time

  • battery standby

    means of automatically switching over to stored battery power during local primary power failure


    correct ratio of mineral content and pH level that prevents the water from being corrosive or scale forming

  • break

    open an electrical circuit

  • breakdown voltage

    voltage at which insulation between two conductors is destroyed

  • brownout

    low line voltage that can cause misoperation of and possible damage to equipment

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  • conductor

    material with the ability to carry electric current; the term is also used for an electric wire

  • current

    flow of electrons through a conductor; current is measured in amperes

  • continuous duty locking unit

    electric lock equipped with a heavy-duty solenoid that can be energized indefinitely

  • continuous duty

    device or control that can operate continuously with no off or rest periods

  • continuity check

    test performed on a length of wire or cable to determine whether the electrical current flows continuously throughout the length

  • continuity

    state of being complete and uninterrupted, like a normally closed circuit

  • contacts

    electrically conductive points, or sets of points, used to make or break an electrical circuit mechanically

  • connector

    any device used to provide rapid connect/disconnect service for electrical cable and wire terminations

  • conduit

    tube or trough for protecting electrical wires or cables

  • coil, electric

    successive turns of insulated wire that create a magnetic field when an electric current is passed through them


    mechanical device in a pipe that permits the flow of water or air in one direction only

  • code

    see national electrical code

  • closure

    point at which two contacts meet to complete a circuit

  • circuit, open

    1. electrical circuit in which current does not flow until permitted by the closing of a switch or a switch-type electronic component
    2. circuit or switch in which the contacts are open during normal operation
  • circuit, closed

    1. electrical circuit in which current normally flows until interrupted by the opening of a switch or a switch-type electronic component
    2. circuit or switch in which the contacts are closed during normal operation

    switch, which allows manual override of an electrical circuit. It also automatically breaks the circuit when current fluctuations are detected

  • circuit

    path through which electrical energy flows

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  • decibel (dB)

    increment of measurement used to compare measured levels of sound energy (intensity) to the apparent level detected by the human ear; expressed as a logarithmic ratio (sound that has 10 times the energy of another sound is said to be 10 decibels louder; 100 times the energy is 20 decibels louder; 1,000 times the energy is 30 decibels louder; and so on); decibel levels are correctly expressed as the number of decibels at a measured distance from source of sound (for example,125 dB at 10 feet)

  • de-energize

    to remove power

  • delay on break

    mode of operation relative to timing devices; delay begins when the initiate switch is opened (delay on break of initiate switch)

  • delay on energization

    1. mode of operation relative to timing devices; delay begins when initiate switch is closed or on application of power to input
    2. also called delay on make
  • delay on make

    see delay on energization

  • direct current (DC)

    electrical current that travels in only one direction and has negative (-) and positive (+) polarity; it may or may not have an AC ripple component; DC sources that are unfiltered should be referred to as full-save or half-wave rectified AC

  • door status switch (DSS)

    used to monitor whether a door is in an opened or closed position

  • double pole, double throw (DPDT)

    1. switch or relay output contact form (2 form C) in which two separate switches are operating simultaneously, each with a normally open and normally closed contact and a common connection
    2. used to make and break two separate circuits
  • dry contact

    metallic points making (shorting) or breaking (opening) a circuit; the switched circuit must have its own source of power and is merely routed through the dry contacts

  • dynamic head

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  • energize

    to apply power

  • equalizer line

    line from below the pool surface to the body of a skimmer, designed to prevent air being drawn into the filter when the water level drops below the skimmer inlet; operates automatically

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  • face piping

    piping, with all valves and fittings, used to connect the filter system together as a unit

  • fail safe

    see fail-unlocked

  • fail secure

    see fail-locked

  • feet of head

    basic measurement of pressure or resistance in a hydraulic system, which is equivalent to the height of a column of water that would cause the same resistance

  • fire door latch

    latch that has a 1/4-inch throw and an anti-friction reactor

  • form c contact

    switch mechanism that contains three terminals (normally open, common, and normally closed)

  • fuse

    protective device, placed in a circuit as a safeguard, that contains a strip of easily melted metal; when the current flow becomes too great, the metal melts, thus breaking the circuit

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  • gold

    very soft ductile material that is noted for its resistance to corrosive metals; it is used primarily as a coating or plating

  • ground

    conducting connection between an electrical circuit and the earth or other large conducting body, thus making a complete electrical circuit

  • ground, earth

    portion of a circuit that is connected to a buried metallic object such as a grounding rod or water pipe

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    work done per unit of time; 1 horsepower equals 33,000 foot-pounds of work per minute or approximately 746 watts; motors for pumps are rated in horsepower

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  • input voltage

    designed power source requirement needed by equipment in order to operate properly

  • inrush

    initial surge of current through a load when power is first applied; lamp loads, inductive motors, solenoids, and capacitive load types all have inrush or surge currents higher than the normal running or steady state currents; resistive loads such as heater elements, have no inrush

  • Interlock

    1. system of multiple doors with controlled interaction
    2. also known as lighttraps, airtraps, mantraps, and sallyports
  • intermittent duty solenoid

    solenoid designed to be energized for short periods; continuous operation may damage an intermittent duty solenoid

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  • line drop

    voltage loss occurring between any two points in a power or transmission line; such loss is due to resistance, reactance, or leakage of the line

  • line supervision

    electrical supervision of a wire run to detect tampering (a cut or shorted wire); usually requires a terminating element at end of monitored wire loop

  • line voltage

    voltage existing in a main cable or circuit, such as at a wall outlet

  • load

    any device that consumes electrical power; the amount of power required for operation of a circuit or motion is obtained that moves the bolt

  • load rating

    control specification outlining the type of load, minimum and maximum currents, and the voltage

  • local alarm

    visual or audible signaling device located at monitored door, window, or other opening

  • lock status sensor (LSS)

    relay type to operate the LED with an SPDT switch to indicate low voltage and tampering of the lock face locally or to a remote monitoring location

  • light emitting diode (LED)

    diode, solid-state device that gives off virtually heatless colored light when electric current is passed through it; LEDs are very efficient, long lasting and are often used for digital readouts and annunciators; common colors include red, green, and amber

  • lighttrap

    see interlock

  • line cord

    cord, terminating in a plug at one end used to connect equipment or appliances to a power outlet

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  • maintained contact switch

    switch designed for applications requiring sustained contact, but with provision for resting

  • make

    to close or establish an electrical circuit

  • mantrap

    see interlock

  • maximum rating

    absolute maximum condition in which a device is designed to operate; voltage, frequency, current, temperature, humidity, shock, and other parameters can be specified as maximum

  • milliampere

    one one-thousandth (0.001) of an ampere

  • millisecond

    one one-thousandth (0.001) of a second

  • mode of operation

    specified operational condition of a switch, lock, door system, etc.

  • momentary duty lock

    electric lock equipped with a solenoid that is energized only momentarily

  • momentary loss of power

    short interruption of power to the total equipment

  • momentary switch

    spring-loaded contact that, when pressed, closes two contacts; when pressure is removed, contacts open

  • monitoring loop

    continuous loop of wire starting at the control panel and running through switches in a system to indicate a breach of security through an open switch or a cut wire

  • mother board

    master printed circuit board used to interface activities of individual printed circuit boards and the devices being controlled or monitored; the mother board is usually located at the back of a control panel assembly; individual printed circuit boards plug into it

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  • National Electrical Manufacturers Association (NEMA)

    organization known for its standardization of wire and cable specifications

  • noise

    unwanted and/or unintelligible signals picked up on a cable circuit

  • normally closed (NC)

  • normally open (NO)

  • National Electrical Code (NEC)

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  • Ohms Law

    In electrical systems, there is a relationship between current, voltage, and resistance. This is known as ohms law, and can be written in many different forms, but always boils down to V=IR, where V is voltage, I is current, and R is resistance.

  • operating voltage

    1. voltage by which a system operates
    2. nominal voltage with a specified tolerance applied; design voltage range necessary to remain within the operating tolerances; for example, for a system specified 120 volts +/-10 percent of nominal, 120 volts is the nominal voltage and the design voltage range is 108 to 132 volts AC
  • output voltage

    designed power source produced by a power supply

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  • potentiometer (pot)

    variable resistor

  • primary

    transformer winding that receives the energy from a supply circuit

  • printed circuit board

    means of making electrical interconnections without using insulated wires; printed circuit boards provide a supporting and insulating medium for components and conductors in a form that is readily adaptable to machine assembly

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  • rated voltage

    maximum voltage at which electric component can operate for extended periods without undue degradation or safety hazard

  • rectifier

    solid state electrical device that will allow current to flow in one direction only; it is designed to convert alternating current to direct current

  • recycle time

  • regulated power supply

    power supply that provides a constant output regardless of input voltage variations

  • relay

    electrically controlled-device that opens and closes electrical contacts to effect the operation of other devices in the same or another electrical circuit

  • remote alarm

    visual or audible signaling device used to signal violations at locations removed from the central control station or monitored openings; for example, a remote alarm may be placed on a roof, or at guard stations outside a building

  • remote reset

    switch located at a monitored opening; if a violation occurs, the alarm at the main control console cannot be turned off until the door is secured and the remote reset is activated; its purpose is to ensure the inspection of an opening that has been violated or left open

  • reset time

    time required to return the output to its original condition

  • resistance

    1. opposition to flow of an electric current (measured in ohms)
    2. reciprocal of conductance
  • resistor

    circuit element whose chief purpose is to oppose the flow of current

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  • secondary

    transformer winding that receives energy by electromagnetic induction from primary

  • security condition sensor (SCS)

    sensitive crystal relay to operate the LED with an SPDT switch to indicate low voltage and tampering of the lock face locally or to a remote monitoring location; primarily used in higher security applications

  • security interlock

    multidoor system in which all doors are normally closed and locked; releasing one door disables the releases for all other doors until the first door is closed and relocked

  • short

  • single pole, double throw (SPDT)

    switch or relay contact form (1 form C) that has a normally open and a normally closed contact with a common connection

  • single pole, single throw (SPST)

    switch with only one moving and one stationary contact, available either normally open (NO) or normally closed (NC)

  • solenoid

    1. electromechanical device that operates the lockbolt
    2. when electricity is applied, a mechanical device
  • spike

    momentary increase in electrical current; spikes can damage electronic equipment

  • switches

    devices that make or break connections in an electrical or electronic circuit; switches are usually manually operated but can also work by mechanical, thermal, electromechanical, barometric, hydraulic, or gravitational means

  • switch, maintained

    switch that, when activated, maintains its activated position until it is inactivated

  • switch, momentary

    see momentary switch

  • switch, normally closed

    see normally closed

  • switch, normally open

    see normally opened

  • Sally ports

    see interlock

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  • transformer

    1. electric device that changes voltage in direct proportion to currents and in inverse proportion to the ratio of the number of turns of its primary and secondary windings
    2. see primary and secondary
  • transient

    any increase or decrease in the excursion of voltage, current, power, heat and so forth, above or below a nominal value that is not normal to the source

  • transient voltage

    1. refers to several parameters of a transient
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  • volt (V)

    1. unit of electromotive force
    2. the difference of potential required to make a current of one ampere flow through a resistance of one ohm
  • voltage

    term most often used (in place of electromotive force, potential, potential difference, or voltage drop) to designate electrical pressure that exists between two points and is capable of producing a flow of current when a closed circuit is connected between the two points

  • voltage drop

    voltage loss experienced by electrical circuits due to two principal factors

  • volt/amp (VA) rating

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  • watt

    common unit of electrical power; one watt is dissipated by a resistance of one ohm through which one ampere flows

  • wire

    slender rod or filament of drawn metal

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  • zone

    1. specific area of protection
    2. portion of a large protected area
    3. power supply to operate equipment
  • Zone

    1. specific area of protection
    2. portion of a large protected area
    3. power supply to operate equipment
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