Shenzhen Zhongnuo Inspection Technology Co., Ltd. is based in South China, offering explosion-proof construction services, safety inspections, renovations, project acceptance, and explosion-proof installation consulting. We are well-versed in explosion-proof construction standards, boasting experienced construction teams with rich practical experience. We have served major corporations such as PetroChina, LG, Hanlan Environment, BOE, and Sinovac Biotech, receiving consistent praise and trust from our clients!
In recent years, with the continuous development of society and the increasing prominence of safety accidents, people's awareness of safety production has been on the rise, and the governance of potential hazards in dangerous environments is urgently needed.
In various industrial sectors in our country, such as oil, chemicals, ports, coal, and others, during the production, processing, transportation, and storage processes, there is often a risk of leaks or spills of flammable and explosive gases, liquids, dust, and fibers. When these substances mix with air, they can form explosive mixtures. If the concentration of the mixture reaches the explosive range, any ignition source can trigger an explosion and lead to severe accidents, including fires and even chain reactions causing major incidents. Therefore, equipment used in such hazardous environments must be certified and equipped with explosion-proof features. The use of all equipment in explosion-proof environments must be installed and debugged by experienced engineering companies in strict accordance with explosion-proof construction specifications and acceptance standards before being put into actual production use. This ensures the maximum safety requirements for all stages of the production process.

Standard for Explosion-proof Construction Acceptance - Shenzhen ZhongNuo Testing Technology Co., Ltd.
G50058 Specification for Design of Electrical Installations in Explosive Hazardous Environments
GBJ54-83 "Code for Design of Low-Voltage Distribution Systems and Lines"
G50016 Building Design Fire Prevention Code
AQ3009 Electrical Explosion-Proof Safety Standards for Hazardous Locations
GB/T3836.1 "Explosive Atmospheres, Part 1: Equipment - General Requirements"
GB/T3836.15 "Design, Selection, and Installation of Electrical Equipment for Explosive Environments"
GB50257 "Code for Construction and Acceptance of Electrical Installations in Explosive and Fire Hazardous Environments"
14J938 "Explosion-Resistant and Explosion Ventilation Windows, Roofs, and Wall Construction"

Basic Requirements for Explosion-Proof Electrical Installations in Explosive Areas (Shared by Shenzhen ZhongNuo Testing Technology Co., Ltd.)
1. Oil-immersed equipment should be used under conditions of no vibration, no inclination, and fixed installation.
2. When using non-explosion-proof equipment for mechanical transmission as partition walls, the following regulations should be observed:
The room housing electrical equipment should be separated from the explosive hazard area by a solid wall made of non-combustible material.
(2) For the drive shaft transmission through the partition, a stuffing box seal or an equivalent effective seal should be used.
(3) The exit of the electrical equipment room should lead to an environment free of explosive hazard areas.
(4) When the room housing the equipment must be connected to an explosive atmosphere, the explosive atmosphere should be maintained at a positive pressure relative to the room.
3. Electrical wiring and equipment in explosive environments, excluding inherently safe circuits, should be equipped with overload, short-circuit, and grounding protection. Electrical equipment that cannot experience overload does not require overload protection. Motors in explosive environments, in addition to the necessary protection as required by current standards, should also be equipped with phase failure protection. If the automatic shutdown of electrical equipment could pose a greater risk than the ignition hazard, an alarm device should be used in place of the automatic shutdown device.
4. In emergency situations, appropriate measures should be taken at suitable locations outside of hazardous areas to disconnect the power to the equipment in the hazardous area. Continuous operating equipment should not be included in the emergency shutdown circuit and should be installed on a separate circuit to prevent the occurrence of additional hazards.
5. The design of substation, distribution station, and control room shall comply with the following regulations:
Transformer stations, distribution stations (including distribution rooms, etc.), and control rooms should be located outside of explosive atmosphere environments. When they are in a positive pressure room, they can be situated within Zones 1 and 2.
(2) For explosive gas environments heavier than air, the equipment floor of the substation, distribution station, and control room located in the additional 2 zone of the explosion hazard area should be elevated 0.6 meters above the exterior ground level.

Selection of cables and wires for explosive environments shall comply with the following specifications: (Shared by Shenzhen Zhongnuo Testing Technology Co., Ltd.)
In explosive environments, the rated voltage of insulated conductors and cables used for low-voltage power and lighting circuits should be higher than or equal to the working voltage, and U0/U should not be lower than the working voltage. The rated voltage of the neutral line should be equal to the phase line voltage, and it should be laid in the same sheath or protective conduit.
(2) In areas where explosion hazards exist, uninsulated wires should not be used as supply and distribution lines, except within switchboards, wiring cabinets, or wiring systems using metal conduit.
(3) Copper-core cables should be used in Zone 1. In Zone 2, copper-core cables are preferred except for inherently safe circuits. When aluminum-core cables are used, their cross-sectional area must not be less than 16 square millimeters, and copper-aluminum transition joints should be used for connections to electrical equipment. Circuits installed in explosive dust environment Zones 20 and 21, as well as in areas of severe vibration within Zone 22, should use copper-core insulated conductors or cables.
(4) The technical requirements for wiring of cables in explosive environments, excluding the circuit of this pressure safety system, should comply with the specifications in Table 5.4.1-1.
(5) Technical requirements for piping wiring in explosive environments with voltages below 1000V, excluding circuits of intrinsic safety systems, shall comply with the specifications of Table 5.1.1-2.
(6) In explosive environments, the selection of insulated conductors and cable cross-sections must comply with the provisions of Tables 5.4.1-1 and 5.4.1-2, as well as the following regulations:
1) The conductor's current-carrying capacity should not be less than 1.2 times the rated current of the fuse element and 1.2 times the setting current of the long-time overcurrent release of the circuit breaker, except for the case of clause 2 in this article.
2) The long-term allowable current for the branch line of squirrel-cage induction motors with a voltage rating below 1000V should not be less than 1.2 times the rated current of the motor.
(7) When installing overhead or bridge-mounted cables, flame-retardant cables are recommended. Plastic sheathed cables can be used without armor when the installation method employs bridge structures capable of preventing mechanical damage. Non-armor cables can also be used for installations in cable trenches in Zones 2 and 22 where there is no risk of damage from rodents or insects.
explosion-proof electrical modification in explosive hazardous areas and site explosion-proof construction consulting services - Shenzhen Zhongnuo Inspection Technology Co., Ltd.