Electrical Installations in Diverse Environments: A Comprehensive Guide
1. Electrical Installations in Moist Environments
Moist or wet sites are characterized by brief or prolonged condensation, salt or rust stains, or water impregnation on ceilings and walls.
1.1. Busbar
Pipes, terminals, splices, and connections must be sealed to achieve an IPX1 rating (protection against vertically falling water droplets). This applies to busbar trunking as well.
1.2. Switchgear
Junction boxes, switches, sockets, and all switchgear must have an IPX1 rating. Covers and accessible parts of control devices should not be made of metal.
1.3. Lighting
Lighting receptors must be protected against vertically falling water (IPX1) and should not be Class 0. Portable lighting equipment should be Class II, as per ITC-BT-43.
2. Electrical Installations in Wet Environments
Wet locations are characterized by moisture-impregnated floors, ceilings, and walls, with potential for thick mud, water droplets, or prolonged mist. Examples include public washrooms, factories, and outdoor facilities.
2.1. Pipes
Wiring must be watertight, using terminals, splices, and connections with an IPX4 rating (protection against water projections). Busbar trunking should also have an IPX4 rating.
2.2. Switchgear
Control, protection devices, and power outlets should be installed outside wet premises. If not possible, they must have an IPX4 rating or be enclosed in boxes providing equivalent protection.
2.3. Protection Devices
As per ITC-BT-22, a guard must be installed at the origin of each circuit entering the wet location from another area.
2.4. Mobile or Portable Devices
Mobile or portable devices are prohibited unless used for circuit protection separation or with SELV (Safety Extra Low Voltage) as per ITC-BT-36.
2.5. Lighting
Lighting receptors must have an IPX4 rating and should not be Class 0.
3. Electrical Installations in Corrosive Environments
Corrosive environments contain gases or vapors that can damage electrical equipment. Examples include chemical factories and warehouses.
4. Electrical Installations in Dusty Environments (No Fire or Explosion Risk)
Dusty locations expose electrical equipment to dust levels that can cause deterioration or malfunction.
5. Electrical Installations in High-Temperature Environments
High-temperature locations frequently experience ambient temperatures exceeding 40°C or consistently above 35°C.
6. Electrical Installations in Very Low-Temperature Environments
Very low-temperature locations experience ambient temperatures below -20°C, such as freezing chambers in refrigeration plants.
7. Electrical Installations in Battery Rooms
Battery rooms, due to potential gas emissions, are considered corrosive environments and must meet specific requirements:
- Electrical equipment must be protected from fumes and gases released by the electrolyte.
- Adequate natural or forced ventilation is required.
- Artificial lighting should be incandescent or discharge type.
- Luminaries must be corrosion-resistant and prevent gas ingress.
- Batteries require secure and permanent insulation between live parts and earth, with additional moisture-resistant insulation.
- Batteries should be easily replaceable and maintainable, with service corridors at least 0.75 meters wide.
- If the DC operating voltage exceeds 75 volts with respect to bare earth, and accessible parts could touch the ground, service aisles must be electrically insulated.