The vocabulary of event power.

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Urea solution injected into the exhaust of modern diesel engines, including many Stage V generators, to reduce nitrogen oxide (NOx) emissions through an SCR catalyst. The generator uses it on top of its fuel, so it has to be planned in the logistics, just like diesel or HVO.

Distribution cabinet (armoire de distribution)

Mobile electrical assembly that takes a high-current incoming supply, for example 125 A or 400 A, and splits it into protected outgoing circuits, for example 16 A, 32 A or 63 A, feeding the distribution boxes and equipment.

Power assessment (bilan de puissance)

Inventory of all the electrical equipment at an event, with each item's power, connection type and diversity factor. It is used to size the sources, cables and protection devices.

Single-core cable (câble unifilaire)

Cable with a single conductor of large cross-section, for example 150 or 240 mm². For high currents, each phase, the neutral and the earth have their own cable, connected with Powerlock connectors. Not to be confused with the single-line diagram.

Rating (calibre)

Nominal current of a protective device or connector, in amperes. Common standard ratings in events are 16, 32, 63, 125, 250 and 400 A. The rating of a protective device must remain compatible with the size of the cable it protects.

Safety officer (chargé de sécurité)

Professional appointed by the organiser of a trade show or exhibition to ensure that safety rules are followed, particularly on stands. They are the ones who refuse ilotage.

Voltage drop (chute de tension)

Drop in voltage along a cable, caused by its resistance. It increases with length and current, and decreases as the cross-section increases. The French standard NF C 15-100 limits it to 3% for lighting and 5% for other uses on an installation supplied from the public low-voltage grid.

Stand power box (coffret de stand)

Small distribution board that supplies a single stand at a trade show or exhibition. It is fitted with a 30 mA RCD to protect people.

Temporary metered connection (compteur forain)

Temporary connection to the public distribution grid, with metering, used to supply a temporary event such as a fair, a market or a festival.

Grid connection agreement (convention de raccordement)

Document drawn up with the distribution network operator, in France usually Enedis, setting the technical and financial conditions of a grid connection: power, connection point, works to be carried out. For a grid-connected event, it is the starting point of the electrical chain.

Power factor, cos φ (facteur de puissance)

Ratio of active power, in watts, to apparent power, in volt-amperes. It equals 1 for a purely resistive load and is lower for motors or some electronic power supplies.

Load shedding (délestage)

Deliberately disconnecting non-priority loads when the power demand exceeds what the source can supply, to keep essential equipment running. It is planned from the power assessment stage, by ranking the outgoing circuits by priority.

Cable designation: 3G2.5, 5G16… (désignation des câbles)

Notation giving the number of conductors and their size: the first figure is the number of conductors, the letter G indicates a green-and-yellow protective conductor, and the last number is the cross-section in mm². A 5G16 cable therefore has five 16 mm² conductors (three phases, neutral and earth), and a 3G2.5 cable three 2.5 mm² conductors (phase, neutral and earth).

30 mA RCD (différentiel 30 mA)

Device that cuts the circuit when it detects a leakage current of 30 mA, for example through a person's body. It is what protects people against electrocution.

Circuit breaker (disjoncteur)

Protective device that cuts a circuit when the current exceeds its rating (overload) or in the event of a short circuit. Its breaking capacity is expressed in kiloamperes (kA).

ERP, public-access building (établissement recevant du public)

French category for buildings open to the public: performance venues, exhibition centres, stadiums, marquees… Electrical installations there, including temporary ones, follow specific safety rules and undergo regulatory inspections.

Diversity factor (foisonnement)

Coefficient between 0 and 1 that reflects the fact that not all appliances run at full power at the same time. A realistic diversity factor avoids oversizing the installation.

Generator (groupe électrogène)

Combustion engine that drives an alternator to produce electricity. Control electronics keep the voltage and frequency stable.

Twin zero-interruption generator set (groupe Twin zéro coupure)

Two synchronised generators, each supplying 50% of the load and each sized to carry the whole load on its own. If one fails, the other takes over the whole load without interruption. Configurations with 3 or 4 synchronised generators also exist.

Generator technician (GroupMan)

Technician in charge of monitoring and operating the generators during an event.

Electrical authorisations (habilitations électriques)

Authorisations issued by the employer, after training, to carry out operations on or near electrical installations, under the French standard NF C 18-510. Their codes define the scope: H0 for non-electrical work near high-voltage installations, B2V for low-voltage electrical work, including work nearby, BR for general low-voltage interventions, BC for low-voltage isolation (lockout).

HVO

Renewable fuel made from hydrotreated oils and fats (Hydrotreated Vegetable Oil), which can be used instead of diesel in compatible generators.

Hybrid power (hybridation)

Combining a battery pack with a generator: the battery supplies low loads and covers peaks, and the generator only starts when demand or recharging requires it. The result is fewer generator running hours, so less fuel burned and less noise.

Stand-to-stand feeding (ilotage)

Powering a stand from another stand's box. It is systematically refused by trade show safety officers, because it prevents the RCD protection from doing its job properly.

Changeover switch (inverseur de sources)

Device that switches an installation's supply from one source to another, for example from the grid to a standby generator during an outage. An interlock prevents both sources from feeding the circuit at the same time. Switching, manual or automatic, usually involves a brief interruption.

kVA and kW

The kW measures active power, the power actually consumed. The kVA measures apparent power, which determines the size of cables, protection devices and sources. Active power = apparent power × cos φ.

Single-phase and three-phase (monophasé et triphasé)

On a 230/400 V network, single-phase supplies 230 V between a phase and the neutral. Three-phase supplies 400 V between phases and carries more power for the same current.

Build, show, derig (montage, exploitation, démontage)

The three phases of an event: the build installs and commissions the power distribution, the show covers the event itself with electrical standby, and the derig takes down and packs up the equipment. These are the dates to give in a quote request.

Calculation note (note de calcul)

Engineering office document that justifies the choices made for an installation: cable sizes, ratings and selectivity of protective devices, voltage drop. It accompanies the single-line diagram and serves as the reference during inspections.

P17

Name commonly used in France for industrial sockets and plugs complying with the CEI 60309 standard (IEC 60309), in 16, 32, 63 and 125 A, single-phase or three-phase. They are the standard for event power distribution.

Battery pack (pack batterie)

Mobile energy storage that powers an event without a combustion engine, on its own or in a hybrid setup with a generator. Its power is expressed in kVA and its capacity in kWh, for example 90 kVA for 120 kWh.

Cable protector (passage de câbles)

Floor-laid protection that channels and protects cables across circulation areas. Wheelchair-accessible ramps allow people with reduced mobility to cross them.

Site layout plan (plan d'implantation)

Plan showing where the sources, transformers, distribution cabinets and boxes are placed on site, respecting safety distances and access routes. It goes hand in hand with the cable routing plan.

Delivery substation (poste de livraison)

Installation through which a site connected at high voltage (HTA, usually 20 kV in France) receives power from the grid, with metering and protection. A transformer then steps the voltage down to 230/400 V. The primary substation (poste source) is the network operator's installation that supplies a whole area.

Powerlock

High-power, single-pole locking connectors, one per phase, one for neutral and one for earth, used for links of 400 A and above between sources and distribution cabinets.

Earth electrode (prise de terre)

Electrical connection between the installation and the ground. At an event, it is made with earth rods driven into the ground and connected to the protective conductor. It carries fault currents to earth: together with the RCD, it protects people.

Import capacity (puissance de soutirage)

Maximum power a site can draw from the grid, set by its connection contract. For an event, it shows what the venue can supply without reinforcement: beyond that, a temporary connection, a generator or a battery is needed.

Pass-through outlet (recopie)

Outlet on a distribution cabinet or box with the same rating as its incoming supply, used to feed another piece of equipment in cascade.

Single-line diagram (schéma unifilaire)

Simplified representation of an electrical installation in which each link is drawn as a single line, from the source to the outgoing circuits, with the protection devices and ratings.

Cable size (section de câble)

Cross-sectional area of a cable's conducting core, expressed in mm². It is chosen according to the current, the length, the installation method and the permissible voltage drop.

Selectivity (sélectivité)

Coordination of protective devices so that, in the event of a fault, only the device immediately upstream trips. The rest of the installation stays powered: a fault on one stand does not shut down the whole hall. It is checked in the calculation note.

Stage V

The most stringent level of the European regulation on emissions from non-road mobile machinery engines (Regulation (EU) 2016/1628), which applies in particular to mobile generators.

Generator synchronisation (synchronisation des groupes)

Paralleling several generators on the same network: before they are coupled, their voltages, frequencies and phases must match. The generators then share the load, which is the principle of the Twin zero-interruption generator set.

Blue and yellow tariffs (tarif bleu et tarif jaune)

Former names of connections to the French low-voltage grid: tarif bleu up to 36 kVA, tarif jaune from 36 to 250 kVA.

Four-pole, 3P+N (tétra)

Four-pole connection or distribution cabinet: three phases and a neutral, plus earth.

Main distribution board, MDB (TGBT)

Main low-voltage board, at the origin of the installation, which receives the main supply and feeds the distribution cabinets.