Shenzhen ZhongNuo Inspection Technology Co., Ltd. is based in South China, offering explosion-proof construction on-site services, safety inspections, renovations, project acceptance, and explosion-proof installation consulting. We are well-versed in explosion-proof construction standards, with experienced construction teams and a wealth of experience. We've served major corporations such as PetroChina, LG, Huanlan Environment, BOE Technology Group, and Sinovac Biotech, and have consistently received positive feedback and trust from our clients!
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 in partition walls, the following regulations should be observed:
The room for installing electrical equipment should be separated from the explosive hazard area by solid walls made of non-combustible materials.
(2) Transmission shafts should be sealed at the partition wall with gland packing or an equivalent sealing method.
(3) The exit of the electrical equipment room should lead to an environment free from explosive hazard areas.
(4) When the room where the equipment is installed must be connected to an explosive atmosphere, the explosive atmosphere should be maintained at a positive pressure relative to the room.
3. Electrical lines and equipment in explosive environments, excluding intrinsic safety circuits, should be equipped with overcurrent, short-circuit, and grounding protection. Overcurrent protection is not required for electrical equipment that cannot experience overloads. Motors in explosive environments should be fitted with phase failure protection in addition to the necessary protection as required by current standards. If the automatic shutdown of electrical equipment could pose a greater risk than the ignition hazard, an alarm system should be used instead of the automatic shutdown device.
4. In emergency situations, measures should be taken at a suitable location or position outside the hazardous area to disconnect the power to the equipment. Continuous operating equipment should not be included in the emergency shutdown circuit and should be installed on a separate circuit to prevent additional hazards.
5. The design of transformer stations, distribution stations, and control rooms 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 arranged in Zones 1 and 2.
(2) For explosive gas atmospheres where the gas is denser than air, the equipment floor of electrical and instrumentation in substations, distribution stations, and control rooms located in the additional 2 zone of the explosion hazard area should be elevated 0.6 meters above the external ground level.

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 urgent.
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. Once the concentration of the mixture reaches the explosive range, any ignition source can trigger explosions and severe fires, potentially leading to catastrophic chain reactions. Therefore, equipment used in such hazardous environments must be certified with explosion-proof capabilities. 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.

Selection of cables and wires for explosive environments shall comply with the following regulations: (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, with U0/U not less than the working voltage. The rated voltage of the neutral wire should be equal to the phase voltage and should be laid in the same sheath or protective conduit.
(2) In explosive hazard zones, except within distribution panels, wiring cabinets, or metallic conduit wiring systems, uninsulated wires should not be used as supply and distribution lines.
(3) Copper-core cables should be used in Zone 1. In Zone 2, it is advisable to use copper-core cables, 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 environments in Zones 20 and 21, as well as in areas with severe vibration within Zone 22, must use copper-core insulated conductors or cables.
(4) In addition to the circuitry of this pressure safety system, the technical requirements for cable wiring in explosive environments shall comply with the specifications of Table 5.4.1-1.
(5) Technical requirements for steel pipe wiring in explosive environments with voltages below 1000V, except for circuits of intrinsic safety systems, should comply with the specifications in 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 requirements:
The conductor's 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 delay 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 without armor can be used when the installation method employs bridges that prevent mechanical damage. Non-armor cables can also be installed in cable trenches within Zones 2 and 22 when there is no risk of damage from rodents or insects.

Shenzhen Zhongnuo Testing Technology Co., Ltd. offers explosion-proof construction service in the field of:
Explosive gas environments and hazardous areas with flammable or explosive dust in various industries and sectors, including petrochemicals, metal smelting, fine chemicals, petrochemical ground facilities (gas stations, fueling stations, petrochemical storage and transportation), new energy, special equipment, nuclear power, tunnels, grain processing, wood processing, metal product manufacturing, environmental protection engineering, and more, pose risks. Ensuring explosion-proof safety in these dangerous areas is crucial for safeguarding the economic development of our country and its people.
Explosion-proof electrical modifications and on-site explosion-proof construction consulting services for hazardous areas — Shenzhen Zhongnuo Inspection Technology Co., Ltd.