Shenzhen Zhongnuo Testing 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, boasting experienced construction teams and a wealth of practical experience. We have served major corporations such as PetroChina, LG, Huanlan Environment, BOE Technology Group, and Sinovac Biotech, earning consistent praise and trust from our clients!
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 Equipment and Lines"
G50016 Building Design Fire Protection Code
AQ3009 Electrical Explosion-Proof Safety Standards for Hazardous Areas
GB/T3836.1 "Explosive Atmospheres – Part 1: Equipment – General Requirements"
GB/T 3836.15 "Design, Selection, and Installation of Electrical Equipment for Explosive Environments"
GB50257 "Code for Construction and Acceptance of Electrical Installation Works in Explosive and Fire Hazardous Environments"
14J938 "Explosion-Proof and Explosion Ventilation Windows, Roofs, and Wall Construction"

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, and U0/U should not be lower than the working voltage. The rated voltage of the neutral wire should be equal to the phase voltage, and it should be laid in the same sheath or protective tube.
(2) In explosive hazard zones, except within distribution boards, 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, copper-core cables are recommended except for intrinsically 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, should use copper-core insulated conductors or cables.
(4) In addition to the circuit of this pressure safety system, the technical requirements for cable wiring in explosive environments shall 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, 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:
1) The conductor's allowable 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 delay overcurrent release of the circuit breaker, except for the circumstances specified in clause 2 of this article.
2) The long-term permissible 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 cable trays, flame-retardant cables should be used. Plastic sheathed cables can be used without armor when the installation method employs bridge trays that prevent mechanical damage. In areas 2 and 22, where there is no risk of damage from rodents or insects, cables installed in cable trenches can be non-armor cables.

Basic Safety Electrical Installation Standards (Shared by Shenzhen Zhongnuo Testing Technology Co., Ltd.)
Explosion-proof electrical installation differs from standard electrical installation, as it is dependent on the environment in which it is located, which requires additional explosion-proof specifications. In accordance with industry requirements, an environment is deemed explosive when a mixture of gas, vapor, mist, or dust with air, upon ignition, can spread to all unburned mixture. An area where a large number or expected number of explosive gas or combustible dust environments are present requires special preventive measures for the structure, installation, and use of electrical equipment, and is called a hazardous area. Explosion-proof electrical installation refers to a task that meets the requirements for explosion-proof electrical equipment, conditions, and personnel, and involves work in explosive environments and hazardous areas, which is highly critical.

Basic Knowledge and Requirements for Cable Use in Explosive Construction Sites (Shared by Shenzhen ZhongNuo Inspection Technology Co., Ltd.)
Installation methods for electrical wiring in explosive gas environments can be divided into cable wiring and conduit wiring methods.
Note: The installation of inherently safe circuits may not be in accordance with this clause.
7.1 General Provisions
7.2 Electrical wiring should be installed in areas with lower explosion hazards or at a greater distance from the source of release, avoiding locations prone to mechanical damage, vibration, corrosion, dust accumulation, and those with dangerous temperatures. When it is not possible to avoid these areas, preventive measures should be taken.
7.3 The selected low-voltage cables or insulated conductors must have a rated voltage higher than the working voltage of the line, and not less than 500V. Insulated conductors must be laid inside conduits.
7.4 Prohibition of overhead lines rated 10kV and below crossing 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.
7.5 Cables and their accessories shall be installed in such a position that, in view of the actual conditions, they are protected against external mechanical damage, corrosion, or chemical influences (such as the effects of solvents), as well as the effects of high temperatures (also see 6.1.2.4.4 for this safety circuit). If these conditions cannot be avoided, protective measures shall be taken during installation, such as using conduits or selecting the cable type (armored cables, shielded wires, seamless aluminum sheathed cables, mineral insulated metal sheathed cables, or semi-rigid sheathed cables, etc., to minimize damage).
7.6 Unsheathed single-core wires should not be used for conductive wiring unless they are installed within a distribution board, enclosure, or conduit system.
Explosion-proof electrical modifications and on-site explosion-proof construction consulting services for hazardous areas — Shenzhen Zhongnuo Testing Technology Co., Ltd.