Insulation Environment (Non-Conductive Environment) Insulation environments should have insulated floors and walls (for equipment rated for voltages not exceeding 500V, with insulation resistance not less than 50kΩ; for voltages exceeding 500V, 100kΩ), and the protective measures are as follows: 1. The distance between exposed conductive parts and between exposed conductive parts and external conductive parts should be at least 2 meters; if outside the reach of an extending arm, it should be at least 1.25 meters. 2. If the above distance cannot be achieved, an insulating barrier should be placed between the two conductive parts, ensuring the distance over the barrier is at least 2 meters. 3. External conductive parts should be insulated, with insulation materials having sufficient mechanical strength to withstand 2000V voltage and, under normal conditions, leakage current not exceeding 1mA. The above arrangement must be permanent, and must meet the above requirements even when portable or mobile equipment is used. Additionally, measures should be taken to ensure that the walls and floors do not lose their original resistance due to moisture, and that external conductive parts cannot introduce potential from the outside. In an insulation environment, 0-class equipment (which only has basic insulation without protective grounding) can be used. Aircraft Ground Power: 2, 36V Aircraft Power Supply; 1, 400Hz Frequency Converter Power Supply; 7, 115/200V Power Supply; 2, 27V DC Power Supply; 5, 400Hz Power Supply; 12, Aircraft Power Supply
Two: Particularly Hazardous Environments 1. Extremely humid, where the relative humidity of the air inside the building approaches 100%. At this point, the ceiling, walls, floor, and objects within the building are completely enveloped in moisture, as in bathrooms, swimming pools, etc. 2. Buildings containing chemically active or organic media, where corrosive vapors, gases, or liquids are frequently or continuously present, forming deposits or mold layers that can damage the insulation and conductive parts of electrical equipment and circuits. Examples include chemical workshops. 3. Buildings that meet two or more of the following conditions of relatively hazardous environments. 4. Locations where outdoor electrical equipment is placed.
Three. Hazardous Environments 1. Wet or dusty environments, where the relative humidity in the building exceeds 75%; or areas where process dust emitted during production can settle on electrical equipment and wires. 2. Locations with conductive floors made of metal, soil, brick, or reinforced concrete. 3. High-temperature environments, where the temperature inside the building is frequently or consistently above 35 degrees Celsius due to various forms of thermal radiation. Examples include buildings equipped with dryers, ovens, calcining furnaces, or boilers. 4. Areas where individuals may come into contact with grounded metal structures, process equipment, and metal pipes within the building, while also simultaneously touching the metal casings of electrical equipment.
