General requirements for fire protection of electrical installations and circuits

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This post was last edited by yunrun on 2021-5-7 at 17:01. In low-voltage power distribution design, fire protection for electrical equipment and circuits is also part of the electrical fire protection design. This article shares the general requirements for fire protection of electrical equipment and circuits for reference by those working in the electrical field. General requirements for fire protection of electrical installations and circuits yunrun.com.cn/tech/3671.html General requirements for fire protection of electrical installations and circuits 1. The selection and installation of electrical equipment shall comply with the operating environment and conditions, to ensure that both the temperatures during normal operation and the expected temperatures under fault conditions do not lead to fires. 2. In the event of a short circuit, ground fault, or overload in the electrical wiring, protective devices must reliably ensure that the power supply is disconnected before the temperature rises to the ultimate temperature of the insulated wires and cables. 3. The protective electrical devices in areas such as flammable material warehouses should ensure that the energy generated by fault currents is not sufficient to ignite nearby combustible materials. 4. For the surface temperature that fixed electrical equipment may reach, necessary measures must be taken to prevent a fire hazard to adjacent materials, such as by employing one of the following effective methods: ① Install or enclose the electrical equipment within a protective cover that can withstand the highest temperature that may occur; this protective cover should be made of non-combustible material with low thermal conductivity. ②Use high-temperature resistant insulation materials to separate electrical equipment from flammable materials. ③Keep electrical equipment at the necessary distance from surrounding flammable materials, and ensure good heat dissipation; its mounting fixtures or supports should be made of insulating material. 5. Arcs or sparks that may be generated by electrical equipment during normal operation should not pose a danger to adjacent materials; otherwise, one of the following measures should be taken: ① Completely enclose the electrical equipment with arc-resistant materials that are non-flammable, have low thermal conductivity, and stable mechanical strength (such as glass fiber silicone sheets with a thickness of at least 20 mm). ②Use arc-resistant materials to separate electrical equipment from surrounding materials. ③Maintain the necessary safety distance between electrical equipment and surrounding materials. 6. Electric equipment installed separately and containing flammable liquids shall have measures to prevent liquid leakage. When the amount of flammable liquid exceeds 25 L, a containment tank for collecting leaked liquid should be installed ； Alternatively, the equipment should be installed in a room with sufficient fire resistance and good ventilation to the outside, and measures should also be in place to prevent flames and smoke generated by liquid combustion from spreading to other areas. Author: Ren Yuanhui