Safe Temporary Electrical Installations for Events & Exhibitions
1. Scope
These requirements apply to temporary electrical installations for fairs, exhibitions, displays, stands, holiday street lighting, festivals, and similar events. The following definitions apply:
- Exhibition: An event for product exhibition or sale, held in a building, temporary structure, or outdoors.
- Display: A presentation or show at any suitable location (building, temporary structure, or outdoors).
- Stand: A temporary area or structure for presentations, marketing, sales, entertainment, etc.
- Amusement Park: An area with rides, booths, attractions, etc., for public amusement.
- Temporary Structure: A unit (or part of one) designed for easy installation, removal, and transportation, including mobile and portable units.
- Temporary Electrical Installation: An electrical installation assembled and disassembled with the associated exhibition, show, stand, etc.
- Source of a Temporary Electrical Installation: The permanent installation point or other supply source feeding the temporary installation.
2. General Features
2.1. Power Supply
Temporary electrical installations for exhibits, shows, stands, and amusement parks shall not exceed 230/400 V AC.
2.2. External Influences
External influences depend on the site and include mechanical shock, water, extreme temperatures, etc.
3. Safety
3.1. Ensuring Protection
Protection against direct and indirect contact is crucial. Barriers or placement out of reach are not accepted for direct contact protection. Greenfield or equipotential bonding is not accepted for indirect contact protection. Regardless of the distribution scheme, public installations must use a residual current device (RCD) not exceeding 30 mA. Direct contact protection must be ensured through insulation rated for a 500V dielectric test for one minute.
3.2. Protection Against External Influences
Automatic disconnection of temporary installations is recommended using an RCD not exceeding 500 mA. These devices are selective for terminal circuits. All lighting circuits (except emergency lights) and outlets below 32A must be protected by an RCD not exceeding 30 mA.
3.3. Overcurrent Protection
All circuits require overcurrent protection with a suitable device at the circuit origin.
4. Fire Protection
Fire risk is elevated due to the temporary nature of the installations and public presence. Consider this when assessing external influences and the nature of processed or stored materials. Electrical equipment should be designed to prevent dangerous temperature rises during normal operation or failure.
5. Protection Against High Temperatures
Lighting equipment (incandescent lamps, bulbs, projectors, etc.) that reach high temperatures must be protected from combustible materials. Windows and internally illuminated signs should be made of heat-resistant, mechanically strong, and electrically insulated materials. Ensure adequate ventilation unless displayed items are combustible. In such cases, illuminate windows externally or use low-heat lamps. Stands with concentrated electrical appliances or lighting should have well-ventilated enclosures made of non-combustible materials.
6. Equipment
6.1. Apparatus and Assembly
Control and protection switchgear must be enclosed, requiring a tool or key to open (except for manually operated parts). Enclosures should have IP 4X (indoor) or IP 45 (outdoor) protection according to UNE 20324.
6.2. Electric Cables
Indoor cables: Minimum 300/500V rating (UNE 21027 or 21031), suitable for mobile services.
Outdoor cables: Minimum 450/750V rating with polychloroprene or similar cover (UNE 21027 or 21150), suitable for mobile services.
Holiday lighting: Flexible cables (UNE 21027 or 21031).
Connecting cables and flexible cords: Maximum 2m length.
6.3. Conduits
Wiring must be through conduits or channels (ITC-BT 20 and 21). Metallic or non-metallic conduits require IP4X protection (UNE 20324).
6.4. Other Equipment
6.4.1. Luminaires
Fixed luminaires below 2.5m or in accessible areas must be securely fixed to prevent risks. Access to the interior should require a tool.
6.4.2. Emergency Lighting
Install emergency lighting as required by ITC-BT 28 for indoor spaces accommodating over 100 people.
6.4.3. Emergency Switches
An independent circuit for lighting and displays must be controlled by an emergency switch.
6.4.4. Sockets and Outlets
Install enough outlets for safe usage. Ground-level sockets require watertight enclosures and IK 10 impact protection (BS EN 50102). Avoid multi-way adapters and multiple bases (except mobile bases fed from a fixed base with a maximum 2m cable).
6.5. Ground Connections
When using a generator (TN, TT, or IT system), ensure proper grounding. Connect the generator’s neutral conductor or neutral point to accessible conductive parts.
6.6. Protective Conductor
Protective conductor cross-section must comply with ITC-BT-19, paragraph 2.3.
6.7. Boxes and Control Cabinets
Electrical connection boxes and cabinets require the same minimum protection level as in 6.1.