Shenzhen ZhongNuo Inspection & Testing Technology Co., Ltd. offers on-site explosion-proof electrical inspection, explosion-proof project acceptance services, and can provide explosion-proof rectification and construction services for items that fail inspection.
Application Institution for Explosion-Proof Electrical Construction Completion Inspection Report
It's widely known that after electrical work in explosive hazardous areas is completed, third-party organizations must conduct post-construction inspections. Only upon passing the inspection can the facility be put into use. Additionally, beyond the company's regular checks, a facility with explosion-proof inspection qualifications must carry out inspections every three years.
What are the main items inspected during the completion acceptance here?
1. Inspect the explosion-proof electrical equipment for the presence of a label, Ex marking, and clear identification of the type, class, and group of the explosion-proof equipment. Is the label marked with the explosion-proof certification number issued by the inspection unit?
2. Verify that the type, class, group, environmental conditions, and special markings of explosion-proof electrical equipment comply with regulations.
3. Inspect the housing of explosion-proof electrical equipment for cracks or damage; check if the paint is intact, if the junction box cover is securely fastened, and if the fixing bolts and anti-loosening devices are in place.
4. Ensure that oil-filled electrical equipment is checked for oil leakage and seepage, and the oil level should meet the required specifications.
5. Ventilation and exhaust systems of explosion-proof electrical equipment with positive pressure should be unobstructed, connections should be properly made, and the installation positions of inlets and outlets should meet the requirements.
6. Are the extra entry ports of explosion-proof electrical equipment properly sealed in accordance with regulations?
7. The installation of sealed or insulated devices in electrical circuits should comply with regulations.
8. Wiring engineering for intrinsically safe explosion-proof electrical equipment shall comply with design requirements in terms of routing and elevation; the lines should be marked with a sky blue sign.
9. The grounding or earthing of explosion-proof electrical equipment, as well as static electricity grounding, should meet the design requirements and be firm and reliable.
10. Upon completion and acceptance, the relevant documents, materials, manufacturer's product user manuals, test records, certification of compliance, and installation drawings, along with other technical files, should be submitted.
11. At the time of inspection, the following measurement records should also be submitted:
Safety-increase type explosion-proof motor stator and rotor single-sided air gap measurement records.
(2) Adjustment records for pressure relief devices in explosion-proof electrical equipment, such as wind pressure and air pressure relays, high-temperature records of the housing during trial operation of explosion-proof electrical equipment, and test records of static electricity grounding resistance values.
12. Explosion-proof electrical equipment operation records
The shell temperature of explosion-proof electrical equipment, including internal temperatures of intrinsically safe and non-sparking explosion-proof electrical equipment, should not exceed the specified limit.
(2) After the internal wiring of the junction box is securely fastened, the electrical clearances and creepage distances between the live parts and the metal housing should comply with the regulations.
(3) The exhaust port of explosion-proof electrical equipment with positive pressure should not emit sparks. When reducing wind pressure and air pressure, the micro-pressure relay should operate reliably.
(4) Protection devices and interlock devices for explosion-proof electrical equipment should operate correctly and reliably.

Shenzhen ZhongNuo Inspection Technology Co., Ltd. summarizes the experience from previous explosion-proof electrical inspections. The main items and contents of the AQ3009 explosion-proof electrical inspection include:
In accordance with Section 7 of AQ3009-2007 "Electrical Explosion Protection Safety Regulations for Hazardous Areas" (effective as of January 1, 2008): Electrical equipment used in hazardous areas shall undergo initial and periodic inspections. Inspections must be conducted by a qualified explosion-proof inspection agency, with intervals generally not exceeding 3 years. Enterprises shall take corrective actions promptly based on the inspection results and file the Report and the status of corrections with the department of安全生产 supervision and management.
The "AQ 3009-2007 Electrical Safety and Explosion-Proof Code for Hazardous Areas" is a Chinese industry standard, with the preface clearly stating that Chapters 4, 5, 6, and 7 are mandatory and must be strictly enforced. Therefore, such safety regulations are part of the legal system and must be strictly enforced as mandatory requirements!

Shenzhen ZhongNuo Inspection Technology Co., Ltd. summarizes past experiences in explosion-proof electrical inspections, common non-conformities found during on-site explosion-proof electrical inspections:
Currently, hazardous chemical production enterprises in our country often experience frequent accidents, thus demanding a high level of attention to safety production inspections. We should gradually explore the safety performance of products and equipment involving personal safety, and step by step, establish their significant role in safety production inspections. Now, safety inspections can provide technical support to hazardous chemical enterprises, particularly the electrical explosion-proof safety inspections, which should be widely promoted, continuously guiding and serving the enterprises in their safe production efforts.
1. Inadequate design in hazardous areas
Many businesses are constrained by their company history, and at the same time, the production materials of the enterprises are continuously changing, making the demarcation of hazardous areas less uniform and rather chaotic. The layout of equipment and facilities fails to meet the explosion-proof requirements.
2. Understanding of explosion-proof knowledge is relatively weak.
In many hazardous chemical enterprises, there is a lack of distinction between electrical explosion-proof safety inspections and fire protection electrical and building electrical inspections. There is a significant lack of standardization in temporary power use, firework operations, equipment replacements, and electrical management systems.
3. Improper installation of explosion-proof electrical equipment
Although many companies now have explosion-proof features in their electrical facilities, there are still many issues with installation, such as direct wiring connections, missing explosion-proof face screws, and using PVC pipes for wiring through incoming and outgoing pipelines. Additionally, the installation of switches and outlets, wiring terminals, power and lighting distribution boxes, grounding systems, and electrical wiring systems is not very rational, with many safety concerns.
4. Explosion-proof electrical wiring does not meet requirements
In explosive environments, most companies now do not pay enough attention to explosion-proof electrical wiring, fail to correctly understand the technical parameters of hazardous materials in dangerous areas, and often wire arbitrarily.
5. Non-standard grounding of explosion-proof electrical equipment
For explosion-proof electrical equipment grounding, the main types include internal neutral grounding, housing protective grounding, and antistatic grounding. Poor grounding of the unpowered metal housing is common, often resulting in grounding wires being connected to material pipelines.
6. There is a lack of overall planning for explosion-proof zones in the selection of power distribution and control rooms.
Many electrical control rooms and operation rooms are located within explosion-proof zones without proper explosion-proof measures in place.
7. Inadequate explosion-proof selection and requirements for explosion-proof electrical equipment
In electrical explosion-proof facilities, they do not differentiate between environments with combustible dust and those with explosive gases; they are used interchangeably. In various hazardous areas, there are different electrical explosion-proof regulations, markings, and types, as well as varying levels and temperature classes. However, many companies use explosion-proof electrical equipment interchangeably without distinguishing these differences.

Major contents of regular inspection for explosion-proof electrical equipment
1. Model Inspection
In strict accordance with relevant laws, the explosion-proof markings on explosion-proof electrical equipment must be standardized, and the equipment must pass the corresponding explosion-proof standard inspections and be deemed qualified before implementation. It is necessary to design the appropriate explosion-proof type, level, and temperature class for electrical equipment based on the specific working environment.
2. Installation Inspection
During electrical equipment installation, any oversight can potentially lead to losses. For instance, if the ventilation and exhaust system is not properly installed and not adequately ventilated, or if the electrical equipment's casing poses an explosion risk during operation, it is crucial to install with precision and adhere to relevant standards.
3. Line Check
Electrical equipment is often composed of a large number of interconnected wires, which can be particularly complex. If not properly connected, or if there are incorrect connections, or due to the insulation layer of the wires coming off, it can lead to short circuits or overloads, resulting in arcs or sparks. Therefore, it is crucial to strengthen the inspection of circuit connections, especially the sealing of the wires, to ensure that the connections meet the requirements.
4. Grounding Inspection
Electrical equipment generates static electricity during operation. If there's too much static, sparks may occur upon discharge. Therefore, proper grounding protection is essential to promptly dissipate static electricity and prevent explosions. Common grounding methods include working grounding, static grounding, and lightning protection grounding, etc. Engineers must select the appropriate grounding method based on the specific working environment and ensure that the grounding is safe and secure.
On-Site Explosion-Proof Electrical Equipment Regular Inspection Consultancy Services - Shenzhen Zhongnuo Inspection Technology Co., Ltd.