Shenzhen Zhongnuo Testing Technology Co., Ltd. is based in South China and specializes in explosion-proof certification and coal safety certification application consulting services, offering one-stop explosion-proof technology consulting services.
Application Process for the Explosion-Proof Certificate at Shenzhen ZhongNuo Testing Technology Co., Ltd.
1. Conduct product evaluation and initial quotation for the applied product. Evaluate the product based on the company's product specifications, electrical schematics, and component list, determine the appropriate type of explosion-proof certification suitable for the product, and provide an initial quotation.
2. Provide samples for testing at the lab; the quantity of samples required varies depending on the product category.
3. Provide document checklist review
Application documents, including the applicant's information and product details
(2) Technical Documents - The submitted technical documents by the company include corporate standards or technical requirements, product drawings, user manuals, etc.
A. Corporate Standards/Technical Requirements: The corporate standards/technical requirements for products should be written in the prescribed format, including not only performance requirements of the product but also relevant content regarding explosion-proof aspects: such as basic parameters, explosion-proof markings, environmental conditions of use, explosion-proof performance requirements, relevant tests for explosion-proof performance, and markings related to explosion-proof.
B. Product Drawings: When an enterprise applies for an explosion-proof certification for intrinsically safe electrical equipment, it should provide assembly drawings, circuit diagrams, printed circuit board diagrams, silk-screened diagrams, material lists of components, and label diagrams, etc. For non-intrinsically safe electrical equipment, the technical documents submitted for testing should include drawings that reflect the explosion-proof performance of the sample (including assembly drawings and component drawings). If the assembly drawing can clearly indicate the explosion-proof parameters and structure of the product, only the assembly drawing needs to be submitted for testing.
C. Instruction Manual - The instruction manual should include basic parameters, explosion-proof markings, product外形 diagram, installation, maintenance, order instructions, and clear warnings to the user regarding the importance of ensuring the product's explosion-proof performance during installation and use.
D. Other Information: For products with adhesive bonding or casting, provide the model names, performance descriptions, and relevant process documents for the adhesive and casting agents. For plastic shell products, provide the material of the plastic and corresponding performance documents.
4. Issuance of Documents

Division of explosion-proof zones in explosive gas environments
In explosion-proof certification, hazardous areas are divided into explosive gas environments and combustible dust environments based on the different states of substances present in the location. According to the duration of the presence of hazardous substances in the location, the hazardous areas under the two different states are further divided into three zones.
That is: for explosive gas environments, it refers to Zones 0, 1, and 2.
Zones 0: Areas where explosive gas atmospheres are present continuously or for prolonged periods, typically exceeding 1000 hours per year.
Zone 1 - Areas where explosive gas environments may occur during normal operation, typically 10-1000 occurrences per year.
Zone 2 - Under normal operation, explosive gas atmospheres are unlikely to occur or, if they do, they are only temporary and exist for short periods, generally less than 10 hours per year.

What standards are used for explosion-proof certification? What are the technical requirements?
An explosion-proof type is a type of explosion-proof design for electrical equipment.
Its housing can withstand explosive mixtures entering the housing through the housing joint surfaces or structural gaps, without damage upon internal explosion.
And causes ignition of an explosive gas atmosphere formed by one, several gases or vapors.
Explosion-proof casings must have both explosion-proof and anti-explosion capabilities. Generally, the casings of explosion-proof products are rather heavy and are suitable for fixed installations and equipment.
Explosion-proof face width, gap, and roughness are the three key elements of explosion-proof housing design.
Design requirements for the explosion-proof three elements vary depending on the different explosive gas environments in mining Class I, non-mining Class IIA, IIB, and IIC.
Refer to the design standards of GB/T3836.1 and GB/T3836.2 for specifics.
ZheNuo Inspection has long been dedicated to explosion-proof product design, testing, and certification services.
We have a team in the explosion-proof field, well-versed in explosion-proof standard requirements.
We offer explosion-proof housing design, drafting, modification guidance, certification agency services.
If you have a similar need as well, feel free to DM Shenzhen ZhongNuo Testing Technology Co., Ltd. anytime!

Domestic explosion-proof certification modes are categorized into three scenarios -- Shenzhen Zhongnuo Testing Technology Co., Ltd.
1. Explosion-proof certification system
Applicable Products: Electrical and non-electrical equipment used in places with explosive gases and dust, not for mining purposes (except for products listed in the Explosion-Proof 3C Catalogue)
Certification Mode: Product Testing
Certification Certificate: Explosion-Proof Compliance Certificate
Certificate Validity: 5 years
Annual Audit Required: No
2. Explosion-proof 3C Certification System
Applicable Products: Electrical Equipment listed in the Explosion-Proof 3C Catalog
Certification Model: Combination of Type Testing and Factory Audit
Certification Certificate: CCC Certificate
Certificate Validity: 5 years
Annual Audit Required: Yes, an annual audit is required.
3. Coal Safety/Mine Safety Certification System
Applicable Products: Various electrical and non-electrical equipment for use in coal mines and non-coal mine underground operations
Certification Mode: Combination of Type Testing and Factory Audit
Certification Certificate: Mine Product Safety Mark Certificate
Certificate Validity: 5 years
Annual Audit Required: Yes, an annual audit is required
Explosion-proof Certification Application Consulting Service - Shenzhen Zhongnuo Testing Technology Co., Ltd.