Shenzhen Zhongnuo Inspection & Technology Co., Ltd. offers on-site explosion-proof electrical inspection, explosion-proof project acceptance services, and consulting. We also provide explosion-proof rectification and construction services for non-compliant items.
Regular inspection standards and cycles for explosion-proof electrical equipment
With the increasing popularity of explosion-proof electrical equipment, such equipment is now installed and used in many explosive hazard areas.
Many end-users believe that installing explosion-proof electrical equipment in explosive hazardous areas is all that's needed.
In many cases, so-called explosion-proof electrical equipment lacks a valid explosion-proof certificate, or the certificate has expired or is fraudulent. The label does not match the explosion-proof certificate.
Inappropriate explosion-proof type selection, mixing of gas explosion-proof electrical equipment with dust explosion-proof electrical equipment, improper wiring of explosion-proof electrical equipment installation, ungrounded lines.
Holes are drilled in explosion-proof casings, and the installation of buttons can cause explosion-proof failure. Explosion-proof electrical equipment is subject to long-term corrosion, high temperatures, and severe vibrations.
For explosion-proof electrical equipment in use, the AQ 3009-2007 "Electrical Safety and Explosion-proof Code for Hazardous Areas" standard stipulates:
Electrical equipment used in explosion-proof environments should be inspected by a certified explosion-proof specialist center at least every 3 years for performance, installation, and maintenance checks.
Immediate corrective actions must be taken for any non-conformities found during inspections, and the inspection report and corrective measures must be filed with the安全生产监督管理部门.
Conducting explosion-proof site inspections on in-use explosion-proof electrical equipment is not only a requirement of the safety production department, but also a reflection of the company's serious attitude towards its own life and property safety.

Do explosion-proof areas require regular inspections? Which standard specifies this?
In explosive hazardous areas, the installation and use of explosion-proof equipment is a basic requirement. In addition, strict explosion-proof requirements must be met for wiring, grounding, ventilation, penetration through walls, and explosion venting and resistance in such locations.
Do these locations require regular inspections?
Yes. According to the AQ 3009-2007 "Electrical Safety and Explosion Proof Regulations for Hazardous Areas," such locations must undergo regular explosion-proof inspections by a qualified third-party entity, in addition to daily checks, to ensure safety.

The standard(s) referenced in the "Electrical Explosion Proof Inspection Report" issued from the regular inspection of explosion-proof electrical equipment includes but is not limited to:
GB 50058-2014 Code for Design of Electrical Installations in Explosive Hazardous Environments
GB50257-2014 "Code for Construction and Acceptance of Electrical Installation Works in Explosive and Fire Hazardous Environments"
GB/T3836.15-2017 "Electrical Equipment for Explosive Gas Atmospheres – Part 15: Electrical Installations in Hazardous Areas (Excluding Coal Mines)"
AQ3009-2007 Electrical Explosion-Proof Safety Regulations for Hazardous Areas

Ex防爆ElectricalInstallationCompletion and Acceptance Report Application Agency:
It's widely known that after electrical construction in explosive hazard areas, a third-party agency must conduct post-construction inspection before the facility can be put into use. Additionally, apart from the company's regular checks, a periodic inspection by an institution with explosion-proof certification must be carried out every three years.
What are the main contents of the acceptance inspection after completion?
1. Inspect that the explosion-proof electrical equipment has a label, Ex mark, and clear identification of the type, class, and group of the explosion-proof equipment. Does the label indicate the explosion-proof certificate 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 shell 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. Check for oil leakage and seepage in oil-filled electrical equipment, and ensure the oil level meets the required specifications.
5. The ventilation and exhaust systems of explosion-proof electrical equipment with positive pressure should be unobstructed, connections should be correct, and the installation positions of the inlets and outlets should meet the requirements.
6. Are the extra inlets of the explosion-proof electrical equipment properly sealed in accordance with regulations?
7. The installation of sealed or insulated devices in electrical circuits shall comply with regulations.
8. The wiring engineering for intrinsically safe explosion-proof electrical equipment shall comply with design requirements for the route and elevation of the lines; the lines should be marked with a sky blue sign.
9. The grounding or neutral connection of explosion-proof electrical equipment, as well as static electricity grounding, should comply with design requirements and ensure a firm and reliable connection.
10. At the time of completion and acceptance, the relevant documents, materials, manufacturer's product user manual, test records, qualification certificates, and installation drawings, among other technical files, should be submitted.
11. At the time of acceptance, the following measurement records should also be submitted:
Record of the measurement of single-sided air gap of the stator and rotor in explosion-proof motors of increased safety type.
(2) Adjustment records for pressure-relief devices protecting explosion-proof electrical equipment, such as wind and air pressure relays; high-temperature records of the equipment's housing during trial operation; and test records of the grounding resistance for static-dissipative grounding.
12. Explosion-proof electrical equipment operation records
The shell temperature of explosion-proof electrical equipment, including intrinsic safety and non-sparking types, should not exceed the specified value.
(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 of explosion-proof electrical equipment with positive pressure should not blow out sparks. The micro-pressure relay should operate reliably when reducing wind pressure and air pressure.
(4) The protective devices and interlocking devices of explosion-proof electrical equipment should operate correctly and reliably.
On-Site Explosion-Proof Electrical Equipment Regular Inspection Consultancy Service - Shenzhen ZhongNuo Inspection Technology Co., Ltd.