SINO Testing Services| 2022-03-28|Return
The installation and use of explosion-proof electrical equipment in hazardous and explosive areas is the most basic requirement for safety.
But what are the issues to pay attention to when selecting and installing explosion-proof electrical equipment? Below, Zhongnuo Testing will share a few points with you.
1、 The selection of explosion-proof electrical equipment should meet the requirements of hazardous areas
(1) Electrical equipment in explosive hazardous environments should be selected based on the hazard level of the installation location, the group and level of hazardous substances, the type of electrical equipment, and the conditions of use.
(2) The group and level of electrical equipment selected should not be lower than the group and level of hazardous substances in the environment.
(3) When there are two or more hazardous substances, they should be selected according to the hazardous substance with a higher degree of danger.
(4) Gas explosion-proof electrical equipment and dust explosion-proof electrical equipment cannot be mixed.
(5) In explosive hazardous environments, portable electrical equipment should be used as little or as little as possible.
(6) Try to install fewer pin sockets, etc.
(1) In explosive and fire hazardous environments, the installation position, laying method, wire material, connection method, etc. of electrical equipment circuits should be suitable for the regional hazard level.
(2) Sparks and explosion accidents caused by exposed or aged cables should be avoided.
1. Eliminating or reducing explosive mixtures
(1) Eliminating or reducing explosive mixtures includes adopting enclosed operations to prevent the leakage of explosive mixtures;
(2) Clean up accumulated dust on site and prevent the accumulation of explosive mixtures;
(3) Design a positive pressure chamber to prevent explosive mixtures from entering areas with ignition sources;
(4) Take open work or ventilation measures to dilute explosive mixtures;
(5) Fill hazardous spaces with inert or inert gases to prevent the formation of explosive mixtures, etc.
(1) Dangerous equipment should be installed in separate rooms and sealed off on partition walls.
(2) Electric motor partition wall transmission, lighting fixtures partition glass window lighting, etc. are all considered isolation measures.
3. Eliminate ignition sources
(1) Select electrical equipment and design electrical circuits according to the characteristics of explosive hazardous environments and the level and group of hazardous materials.
(2) Maintain safe operation of electrical equipment and electrical circuits. Safe operation includes current, voltage, temperature rise, and temperature not exceeding the allowable range, including good insulation, good connection and contact, overall integrity, cleanliness, and clear markings.
4. Grounding measures
(1) Attention should be paid to grounding in explosive hazardous environments: all non charged metal objects should be connected by equipotential bonding;
(2) If the low voltage is distributed by the grounding system, the TN-S system should be used, and the TN-C system should not be used;
(3) If the low voltage is distributed by an ungrounded system, an IT system should be used and equipped with a protective device that can automatically cut off the power supply in case of severe leakage, or an alarm device that can emit dual signals of sound and light.
According to the AQ 3009-2007 "Code for Electrical Safety and Explosion Protection in Hazardous Areas" standard, explosion-proof electrical equipment in use shall be entrusted to a testing center with explosion-proof professional qualifications for performance, installation, maintenance, etc. testing at least once every 3 years. Any non compliant items must be rectified in a timely manner, and the inspection report and rectification situation must be filed with the safety production supervision and management department.Regular on-site inspections of explosion-proof electrical equipment in use can promptly identify problems in hazardous areas and minimize potential accidents. This is not only a requirement of the safety production department, but also the importance that enterprises attach to their own life and property safety.