Shenzhen Zhongnuo Testing Technology Co., Ltd. is based in South China, offering on-site explosion-proof construction, safety inspections, renovations, project acceptance, and explosion-proof installation consulting services. We are well-versed in explosion-proof construction standards, with experienced construction teams and a wealth of practical experience. We have served major corporations such as PetroChina, LG, Hanlan Environment, BOE Technology Group, and Sinovac Biotech, receiving consistent praise and trust from our clients!
Basic Specifications for Explosion-Proof Design in Hazardous Areas (Shared by Shenzhen Zhongnuo Testing Technology Co., Ltd.)
1. Initially, conduct an overall explosion protection design
2. Directed release of explosive energy. Around the explosion source, comprehensively utilize anti-explosion and venting technology, setting anti-explosion walls and windows in the direction of high population density, office areas, and critical equipment; and venting walls and windows in the direction with few people and no critical equipment.
3. Establish safe distances. Minimize the placement of office areas, residential zones, and critical equipment areas within distances less than the safe margin, unless necessary. If required, implement necessary explosion-proof measures.
4. Conversion of non-blast-resistant buildings to blast-resistant buildings. Within the range less than the safe distance, blast resistance assessment of the buildings should be conducted, and reinforcement for buildings that do not meet blast resistance requirements should be carried out: to prevent building collapse; to prevent the cracking of brittle materials such as bricks, concrete, glass, etc., and the resulting flying debris.
5. Locate explosion-proof shelters in hazardous blast zones.

Basic Specifications for Explosion-Proof Electrical Construction (Shared by Shenzhen ZhongNuo Testing Technology Co., Ltd.)
Explosion-proof electrical installation differs from standard electrical installation due to the increased explosion-proof requirements of its environment. Based on industry requirements, we define an explosive environment as one where gases, vapors, thin mist, or dust mix with air under atmospheric conditions and, upon ignition, the flame can spread to all unburned mixtures. An area where a large or expected number of explosive gas environments or combustible dust environments is present, requiring special preventive measures for the structure, installation, and use of electrical equipment, is known as a hazardous area. Explosion-proof electrical installation refers to a task that meets explosion-proof electrical, environmental, and personnel conditions, conducted in explosive environments and hazardous areas, with strong capabilities.

Protection of explosive circuitry shall comply with the following regulations (shared by Shenzhen ZhongNuo Testing Technology Co., Ltd.)
In the single-phase network within Zone 1, both phase wires and neutral lines should be equipped with short-circuit protection, and appropriate switches should be used to simultaneously disconnect both phase wires and neutral lines.
(2) For 3kV-10kV cable lines, it is advisable to install zero sequence current protection, with the protective devices in Zones 1 and 21 ideally tripping the circuit breakers.

Basic knowledge for explosion-proof electrical construction should include the following points:
1. Classification and grouping of explosive materials, as well as classification and delineation of hazardous explosive areas.
Explosive gases should be classified based on their Maximum Experimental Safe Gap (MESG) or Minimum Ignition Current Ratio (MICR), and grouped according to their ignition temperature. Combustible dusts, categorized by their conductivity, can be divided into conductive and non-conductive types, and grouped by their low ignition temperature. Hazardous areas with explosive risks are divided into two categories: gas explosion hazardous areas and dust explosion hazardous areas. These areas are further classified into three zones (0, 1, and 2) based on the frequency and duration of the presence of explosive gas environments. Hazardous areas with combustible dust/air mixtures are categorized into three zones (20, 21, and 22) based on the frequency and duration of their occurrence and the thickness of the dust layer.
Section 2: Selection of Explosion-Proof Electrical Equipment for Hazardous Areas.
The selection principle for explosion-proof electrical equipment is safety and reliability, economic and reasonable. It should be selected based on the grade of the explosive hazardous area and the category, level, and group of explosive hazardous substances. Refer to the specific selection table in standard AQ3009-2007.
III. Installation of electrical lines and explosion-proof electrical equipment in hazardous explosive areas.
Installation methods for electrical wiring in explosive gas environments can be divided into cable wiring and conduit wiring. 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 hazardous temperatures. If avoidance is not possible, preventive measures should be taken. The low-voltage cables or insulated conductors used must have a rated voltage higher than the working voltage of the circuit and not less than 500V. Insulated conductors must be laid within conduits. For more details, attend training courses on explosion-proof electrical installation, maintenance, and repair.
Four: Inspection and maintenance of explosion-proof electrical equipment in hazardous areas.
To minimize the ignition hazard of electrical equipment in hazardous areas, initial inspections should be conducted before the equipment is put into operation, during the handover and acceptance of the project. For electrical equipment to be used long-term in hazardous areas while in good condition, continuous supervision and regular inspections are required. Initial and regular inspections should be entrusted to safety production testing and inspection institutions with explosion-proof qualifications.
Inspections and maintenance of explosion-proof electrical equipment should be conducted by qualified personnel meeting the specified requirements. These individuals must undergo training in areas including explosion-proof types, installation practices, relevant regulations and procedures, as well as the general principles of hazardous area classification. They should also receive appropriate continuing education or regular training, and possess relevant experience and trained qualifications. Ongoing supervision and regular inspections should be carried out. Maintenance requirements should include reasonable remedial measures and equipment replacement procedures.
Explosion-proof electrical renovations and on-site explosion-proof construction consulting services for hazardous areas - Shenzhen Zhongnuo Testing Technology Co., Ltd.