According to the requirements of the standard AQ3009-2007, explosion-proof electrical equipment in service must be inspected at least once every three years to ensure its explosion-proof safety performance. Based on years of experience in on-site explosion-proof inspections, Shenzhen Sinotest Testing Technology Co., Ltd. has summarized several common issues found in on-site inspections.
（1）Fasteners Missing

（2）Fastener corrosion

（3）No isolation/sealing components installed at wall penetration

（4）The installation bending radius of the flexible conduit is less than 5 times the outer diameter of the conduit

（5）The redundant lead-in ports are either not sealed at all or improperly sealed with plastic components.

（6）The cross-sectional area of the grounding wire is less than 4 mm2
（7）The metal housing of the equipment is not grounded.

In addition, there are problems such as drilling holes in the flameproof enclosure for one hole to pass multiple wires, insufficient thread engagement (less than 5 threads), and no transition compression fitting applied to steel pipe connections, etc.

Periodic explosion-proof inspection can timely detect the problems existing on site and carry out rectification in a timely manner, ensuring the safety of explosion-proof locations.