Glossary of Common Electrical Terms

AC – Alternating Current

ADA RAMP – A type of cable cover system that provides low angle sides for cable crossings which provides wheelchairs and people with mobility challenges a safe and easy path to navigate cable crossings. ADA refers to the Americans with Disabilities Act. In Canada, these ramps are often referred to simply as wheelchair ramps.

AMPACITY – The amperage capacity of cable, connectors, etc.

APPARENT POWER (VA) – The product of voltage and current in an AC circuit. Not true power because Power Factor is not considered in the calculation.

AMPERE (A) – Unit expressing the rate of flow of an electric current.

ARC FLASH – The result from a low impedance connection through air to ground or another voltage phase in an electrical system can cause an electrical explosion or discharge Arc flash generates large amounts of heat that can severely burn human skin and set clothing on fire. Temperatures at the arc can reach four times the temperature of the Sun’s surface. High-intensity flash can also cause damage to eyesight. The high arc temperature vaporizes the conductors in an explosive change in state from solid to vapor.

AWG – American Wire Gauge.

BANDED CABLE/ CWAY – Several single-conductor cables banded together at intervals, forming one bundle. Most commonly using #2AWG cable, in Canadian film this banded cable is known as C-Way.

BONDING – connecting non-current carrying components to a safe path to ground should they accidentally become energized by a hot conductor.

BUSBAR – Thick copper bars inside electrical panels or disconnects to which lug connectors are attached.

CABLE CROSSOVER – A specially designed rubber or urethane ramp used to protect cables from being damaged by vehicle traffic and to reduce tripping hazards for pedestrians. Also known as cable mats or cable ramps.

CALI TWIST – a 50A twist lock connector known as a California Standard connector.

CAM-LOK A single pole locking connector which has become the industry standard in North America for single conductor portable power cables supplying up to 400A 600V. Cam-lok is the patented name of one specific supplier’s product however single pole, cam-type locking connectors from many different manufacturers are often generically called Cam-loks in our industry.

CAPACITANCE – The property of being able to collect a charge of electricity.

CAPACITOR – An electrical device having capacitance.

CEC – the Canadian Electrical Code.

CEEFORM – a European industrial plug or connector which is similar to a Pin and Sleeve connector.

CIRCUIT BREAKER – An overcurrent protection switch. It trips and disconnects a circuit if the current drawn exceeds the rating of the circuit breaker.

CLAMP METER – A meter used to measure amperage. Called a clamp meter because it incorporates “jaws” that clamp around single conductor cables to detect the amperage draw by measuring the strength of the magnetic field created around a cable by the current running through it. Also called an Amp Probe.

COMPANY SWITCH – A company switch is a basic electrical switch design. They are used for power distribution systems in theaters, arenas, convention centers, that often require panel boards for electrical equipment. They often provide cam type connectors eliminating the need to tie in bare wire tails.

 CONDUCTIVITY – the capability of a conductor to carry electricity.

 CONDUCTOR – Any material that allows electrons to flow through it or a wire, or combination of wires, suitable for carrying an electric current.

CONTINUITY – The unbroken flow of electricity through various conductors.

CSA – Canadian Standards Association

CUBE TAP – Converts single receptacle opening to 3 openings in a short cube shaped device.

DC – direct current.

DELTA – a delta connected system provides four-wire, three-phase and three-wire single-phase current. It is the preferred system for AC power transmission.

DISCONNECT – A switch with current limiting fuses to provide circuit protection and a means of disconnecting power.

DUMMY LOAD – Also called a ghost or phantom load, it is a load that is added to a circuit to balance the various legs of power or to bring the entire load up to an optimum operating level. An example of that would be adding a load bank to a generator that is operating in a backup situation with little or no load.

E/J ADAPTER – This an adapter that allows E-1018 standard cam style connectors to work with E-1016 film style cam connectors (ball nose). A long boot on a male E-1018 does not allow for it to be connected to the stubby female E-1016 without this adapter or by cutting back the male boot which will ruin the boot’s watertight specifications. Although both types of cam connectors are “E-Series”, film started to refer to their ball nose style as “E” for entertainment and tapered nose as “J”

EMF – Electromotive Force. Voltage

FEEDER – This cable (in sets of 4 or 5wires) carries power from a source to a branch or distribution panel.

FREQUENCY – Cycles per second measured in Hertz (Hz). North American electrical operates at 60Hz. Europe and Asia at 50Hz.

FUSE – An overcurrent device that uses an alloy ribbon with a low melting point. The circuit is broken when the current exceeds the rating of the fuse and the ribbon melts.

GENERATOR – A device that converts motive power (mechanical energy) into electrical power for use in an external circuit. In our industry, this motive force is usually created by gas or diesel combustion engines.

GFCI – a type of circuit breaker which shuts off electric power when it senses an imbalance between the outgoing and incoming current.

GROUND- an electrical term meaning to connect to the earth or a conducting connection to the earth.

 GROUND ROD / GROUND PLATE – A conductive rod or plate, driven into the earth. Connecting the system ground wire to the grounding rod creates a direct and efficient path to carry current to earth in the case of a fault.

HERTZ (Hz) – see Frequency.

IEC – International Electrotechnical Commission.

IMPEDANCE (Z) – A measure, in ohms of the opposition to current flow in an AC circuit. Impedance includes resistance, capacitive reactance, and inductive reactance

INDUCTANCE – A measure, in henrys, of the opposition to current change in an AC circuit (causing current to lag behind voltage).

INRUSH CURRENT – the initial surge of current experienced before the load resistance of impedance increases to it’s normal operating value.

INSULATION – A non-conductive material to separate conducting material like the jacket of insulated cables.

INSULATOR – Anything that resists electrical flow is an insulator. Insulators are needed in electrical circuits to contain the current flow and prevent shorts or electrocution.

JOY CABLE – 60A 120v three-pin cable used predominantly in the film industry. It uses connectors from the mining industry which looks similar to a stage pin connector.

KVA – 1000 x Volt-Amperes, Apparent Power expressed in thousand volt-amps.

kW – Actual Power expressed in kilowatts.

LED – light emitting diode.

LOAD BANK – A load bank creates resistance to consume electrical energy. It applies an electrical load to an electrical power source and converts (dissipates) the power output of the source. The most common type of load bank is not unlike a giant hair dryer. They are used to prevent ‘wet-stacking’ of generators operating with too little load or can be used to test electrical components under a controlled load during maintenance.

NEUTRAL – The purpose of the neutral wire is to complete the 120volt AC circuit by   providing the path back to the electrical panel where the neutral wire is connected and bonded to the earth ground. In a three-phase system, the difference of the three hots are returned on the neutral wire. Also known as the identified conductor, in North America it is white or gray in color. The neutral is an insulated wire because it is part of the circuit which flows electrical current

OHM (Ω) – A unit of electrical resistance equal to the resistance through which 1V will force 1A.

OUT OF PHASE – properly functioning three-phase rigging motors are said to be in phase. If one or all the motors in a system are operating in the wrong direction, they are said to be out of phase. If all the motors are operating in the wrong direction, swapping any two of the three hot conductors feeding the system will correct the phase. If only one or two of the motors are out of phase, it is usually a result of the individual cables power those motors being wired out of phase. This can be corrected by replacing the cables with ones that are known to be correct until the original ones can be checked and repaired as necessary.

POWER FACTOR (PF) – the percentage of energy used compared to the energy flowing through the wires.

PHASE – An energized single conductor, usually ungrounded and never the Neutral. The positioning of an AC cycle in time, relative to the phases of the other hot legs.

PHASE REVERSAL – Swapping two ‘hots’ reverses the direction of motors.

PHASE ROTATION – Many items we encounter in our industry have three-phase fans or motors that must be rotating in the proper direction. Examples might include fans on broadcast mobile air conditioners, refrigeration units or large chillers/ice plants. Some of these units will automatically check rotation, others have indications as to which direction fans should be turning which can be visibly confirmed on startup. Rotation Meters are available to check rotation. As with out of phase rigging motors, incorrect phase rotation can be corrected by reversing any two of the hot conductors feeding the system.

PIN AND SLEEVE – Common connector for higher loads of typically 60-125 amps

PLUG IN TESTER – A circuit tester which, when plugged into a regular 15A receptacle, will confirm if the circuit is hot, if the polarity is correct and if a grounding wire is present. These testers usually have the ability to test the functionality of a GFCI

POWER – In electrical, the amount of work, measured in Watts.

POWER FACTOR (PF) – In AC, the ratio of the actual or effective power in watts to the apparent power in volt-amperes, expressed as a percentage. Inductive loads cause the current to lag behind the voltage, resulting in a power factor of less than 100%

POWER-LOK (aka Posi-Lok) – A single pole connector, more commonly used in Europe, we see on many tours and installed in some permanent installs locally. The ground neutral and hot connectors have unique alignment slots which will not allow them to be mated incorrectly. These connectors also have a spring-operated insert which acts as a cap/cover, preventing access to open live connectors. They also require a simple tool to un-mate connections which helps to discourage accidental or unauthorized disconnection. Power-lok receptacles incorporate a locking mechanism which also will not allow them to be connected, or disconnected in the wrong order.

REACTANCE (X) – A measure in ohms, of the opposition to AC due to capacitance or inductance.

RECEPTACLE – A female connector or female mounting hardware.

RESISTANCE (R) – A measure, in ohms, of the opposition to current flow in a conductor, device, or load

RGN – designates reverse ground neutral. When single conductor ground and neutral cables provided are reversed from the hot conductors– male outputs on the ground and neutral with female outputs for the hots.

ROOT MEAN SQUARE (RMS) – The effective value of AC or voltage.

SHORT CIRCUIT – a load that occurs when an ungrounded conductor comes in contact with another conductor or grounded object.

SINGLE PHASE – This system consists of two hot 120volt legs and a neutral. By connecting one hot leg and the neutral, you get 120volts. By connecting the two hot legs, you get 240 volts. When the load on one leg is greater than the other, the neutral wire carries the difference.

SOCAPEX – Multi-pin connectors and cables used primarily from dimmer racks to lighting bars or truss rather than using many extension cables.

SPIDER BOX– common term used to describe a construction style distribution panel. Designed for outdoor use, they are often mounted on tall legs or feet to keep them out of water giving them the appearance of a long-legged spider. Predominantly, they have a 50A single phase input which breaks out to multiple 15A or 20A GFCI protected circuits. Over time, the name “spider box” has become a generic name used to describe any type of small distribution panel that breaks out to regular 15A or 20A circuits.

STAGE PIN CONNECTOR – also known as grounded pin connector (GPC) or grounded stage pin (GSP), stage pin connectors are commonly used in theatrical lighting in North America and in many countries in the theater world. These are also sometimes generically referred to as Bates connectors, the brand name of a large manufacturer of stage pin connectors.

STINGER – An extension cord. typically, a “hot” extension cord.

SYSTEM GROUNDING – The ground wire is the safety wire that is connected to the components of a circuit thereby providing a direct path to ground in the event of an electrical fault. In North America, the common color for the ground wire is green however, since the ground wire is not a part of the circuit current flow, some ground wires are not insulated.

THREE PHASE – This system consists of three 120 volt hot legs and a neutral leg. The three phases operate at 60 cycles per second. Each phase operate a third of a cycle out of sync with the next. When a load is connected to any one of the hot wires and the neutral wire the voltage is 120 volts. When a load is placed between two hot wires, because the two phases are a third of a cycle apart the voltage is 208 volts

TIE-IN – The connection of distribution cables to a facility’s service panel box.

TIE-OUT – the removal of distribution cables which were connected to a facility’s service panel box.

TRANSFORMER – ‘Transforms’ power into a higher or lower voltage.

T-TAPS – Allow two Cam-Lok connectors to be plugged into one. MFF FMM

TURNAROUND F/F – This adapter has a female Cam-Lok on each end, which allows you to change a male Cam-Lok to a female Cam-Lok to reverse grounds and neutrals.

TURNAROUND M/M – This adapter has a male Cam-Lok on each end, which allows you to change a female Cam-Lok to a male Cam-Lok to reverse grounds and neutrals.

TWIST LOCK – These connectors can be used with single or 3 phase multi conductor cables up to 50 amps.

TYPE W CABLE – A flame tested cable manufactured to meet US NEC articles regarding portable power cable. It is abrasion, oil, solvent and ozone resistant.

U-GROUND/EDISON – Common extension cord.

VA – Volt-Ampere. In DC, Volts x amperage. Inductance or capacitance creating resistance in AC circuits can cause a discrepancy between Watts and Volt-Amperes.

VOLT TICK TESTER – By sensing the magnetic field of electricity it is useful for cheking to see if a wire is hot. When turned on, the sensor makes an audible beep and lights up as it nears an energized wire. Sometimes called a voltage sensor or an inductance tester.

VOLTAGE DROP – The difference in voltage between two points in a circuit due to intervening impedance or resistance.

VOLTMETER – A meter used to measure voltage potential between two points in a circuit.

WATT – Energy is power applied over time. Power is measured in Watts. It is the product of voltage and amperage.

WET STACKING – refers to unburnt fuel mixed with carbon soot that builds up in the exhaust pipes of diesel generator engines, usually caused by operating the engine for long periods of time at less than 60% of its rated output.

 WYE – a wye-connected system is a common type of three-phase transformer arrangement. Voltage reads 208v between any two hot legs and 120v between a hot leg and the neutral leg. Sometimes called a Star system.

YELLOW JACKET – a manufacturer’s brand name for the original standard designed 5- channel cable mat/ramp. The design is so popular that cable mats from many different manufactures are generically called “Yellow Jackets”.