Shenzhen Zhongnuo Inspection & Technology Co., Ltd. is based in South China and offers explosion-proof technical consulting services, including on-site construction, safety inspections, renovations, project acceptance, and installation. We are well-versed in explosion-proof construction standards, boast experienced construction teams, and have served major corporations like PetroChina, LG, Hanlan Environment, BOE, and Sinovac Biotech, receiving consistent praise and trust from our clients!
Equipment protection grounding in explosive environments should comply with the following regulations (Shared by Shenzhen ZhongNuo Inspection Technology Co., Ltd.)
In accordance with the relevant provisions of the current standard "Code for Grounding Design of AC Electrical Installations" GB/T50065, the following parts that do not require grounding should still be grounded in explosive environments:
1) Non-electrically conducting surfaces, metal enclosures of equipment with an AC rated voltage of less than 1000V and a DC rated voltage of less than 1500V, which are normally not energized.
2) In dry environments, equipment with alternating current rated voltage of 127V or less and direct current voltage of 110V or less typically has non-electrified metal casings.
3) Equipment installed on a grounded metal structure.
(2) In explosive hazardous areas, the exposed, conductive parts of equipment should be reliably grounded. All equipment within explosive zones 0, 20, and 21, and other equipment within explosive zones 2 and 22, excluding lighting fixtures, should use dedicated grounding cables. If the grounding cable is installed in the same protective conduit as the live wire, it should have insulation equal to that of the live wire. Lighting fixtures within explosive zones 2 and 22 may utilize a metallic piping system with reliable electrical connections as grounding, but not using pipelines for conveying materials.
(3) In different directions of the slope in the explosive hazard area, the grounding main should be connected to the grounding body at least twice.

As the world's energy and chemical industries develop, construction in explosive hazardous environments is becoming more widespread, and the prevention and acceptance of such environments are increasingly important.
Especially in places with combustible dust, such as plastic factories, feed/food/grain processing plants, metal polishing and finishing workshops, and paper-making/forestry wood powder/fiber dust factories, the demand for explosion-proof installations, designs, and renovations is also on the rise.
Whether it's large-scale explosion-proofing or local explosion-proofing, if there are hidden dangers in product quality or installation/renovation quality,
Our personnel and property security are at great risk, so we must control the quality at every production stage to ensure the reliability and safety of explosion-proof installations and renovations.
Shenzhen Zhongnuo Testing Technology Co., Ltd. offers explosion-proof construction and modification consulting services, boasting rich qualifications and case studies—definitely worth it!

General Requirements for Explosion-Proof Workshop Design (Shared by Shenzhen Zhongnuo Inspection Technology Co., Ltd.)
4.1 Floor, Interior Wall
Areas producing flammable gases heavier than air or vapors of flammable or combustible liquids, and Class B production workshops with dust or fiber explosion hazards, should use non-sparking floors. To prevent sparks, the floors can be made of materials like rubber, plastic, rubber mixed with graphite, or asphalt concrete.
Interior walls of workshops where combustible dust may settle should be plastered or painted to create easy-to-clean (wipeable) surfaces.
4.2 Office, break room
For personnel safety, do not establish offices or restrooms in Class A or B production buildings with explosive hazards. If necessary, such rooms can be located outside the workshop, separated from the workshop by non-combustible walls with fire resistance of not less than 3.5 hours.
4.3 Electrical Equipment
Electrical equipment in explosion-proof workshops should be selected and installed based on different circumstances, opting for explosion-proof types such as explosion-proof switches, motors, and lighting fixtures, and strictly avoiding non-explosion-proof options.
4.4 Lightning Protection Equipment
In facilities and workshops prone to explosion, in addition to installing lightning protection devices on the building itself, it is required to set up grounded lightning rods around the building as specified. This ensures the building is within the protected range of the entire lightning protection system, preventing accidents caused by lightning strikes.

Installation of electrical wiring in explosive environments shall comply with the following regulations (shared by Shenzhen ZhongNuo Testing Technology Co., Ltd.)
(1) Electrical wiring should be installed in environments with low explosive hazard or far from the source of release, and should comply with the following regulations:
1) When the weight of the material is heavier than air, electrical wiring should be laid at a higher position or directly buried. For overhead installation, cable trays should be used; when using a cable trench, the trench should be filled with sand and drainage measures should be in place.
2) Electrical wiring should be laid outside the walls of buildings or structures where explosion hazards exist.
3) In an explosive dust environment, cables should be laid in areas where dust does not accumulate easily and is easily cleared.
(2) Holes in walls or floors between different areas traversed by electrical wiring trenches, cable trays, or conduits should be tightly sealed with non-combustible materials.
(3) When laying electrical lines, it is advisable to avoid areas susceptible to mechanical damage, vibration, corrosion, ultraviolet radiation, and heat. If avoidance is not possible, preventive measures should be taken.
(4) Conduit wiring can use insulated single-core or multi-core wires without sheathing. When the conduit contains three or more wires, the total cross-sectional area of the wires, including the insulation, should not exceed 40% of the conduit's cross-sectional area. The conduit should be made of low-pressure fluid transport lock zinc-welded steel pipe. The threaded part of the steel pipe connection should be coated with lead oil or phosphating paste. In places where condensation or condensate water may form, sealed joints for draining condensate water should be installed on the pipeline.
(5) Electrical wiring for steel pipe wiring in explosive gas environments should be properly insulated and sealed, and should comply with the following regulations:
1) During normal operation, the 450mm radius around all ignited source enclosures should be sealed off with a partition.
2) Steel pipes with a diameter of 50mm or more should be isolated and sealed within 450mm of the incoming junction box.
3) Isolation and sealing should be conducted between adjacent explosive environments, as well as between explosive environments and adjacent other hazardous or non-hazardous environments. When sealing, the inner surface of the seal should be lined with a fibrous layer as the bottom or separator layer. The effective thickness of the filling layer should not be less than the inner diameter of the steel pipe, and it must not be less than 16mm.
4) Connection components for isolation sealing should not be used for wiring connections or branching.
(6) Intermediate joints are strictly prohibited in Cable Routes within Zone 1, and intermediate joints should not be present in Zones 2, 20, and 21.
(7) When connecting the terminals of cables or wires, if the internal wires are braided, the terminals should be connected with molded terminals or lug connectors. The connection and termination of aluminum-core insulated wires or cables should be done by crimping, soldering, or brazing. When connecting to equipment (excluding lighting fixtures), a copper-aluminum transition connector should be used.
(8) Overhead power lines shall not cross explosive gas environments. The horizontal distance between overhead lines and explosive gas environments should not be less than 1.1 times the height of the tower. Under special circumstances, the distance may be appropriately reduced after effective measures are taken.
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