How to Test Anti-static Grounding Wires in a Workshop
Many electronics factories have installed anti-static grounding, but haven't conducted detailed testing to ensure its compliance. It is recommended that companies with high static electricity requirements test the grounding wires with instruments after installation, or have a professional perform the measurement.
(1) All anti-static grounding wires should use 6 mm² multi-strand copper core insulated wire. Each floor or appropriate section should use copper busbars or switches of grade 401 or higher, connected to the main line for easy inspection and maintenance.
(2) Anti-static grounding cables should be well insulated from equipment casings, workbench frames, work light holders, etc., to prevent short circuits, bridging, or damaged connections.
(3) At the "main line end" of the segmented copper busbars or switches, lay an additional inspection line (1.5~2 mm² is sufficient). Set up 2~3 inspection points in each workshop, fix them securely, and clearly mark them.
Model Measurement Range Ω Minimum Graduation Value Ω Accuracy % ZC29B-1 0～10 0.1 30～100 10～1000 10 ZC29B-2 0～1 0.0 10～10 0.1 0～100 12. The change in auxiliary grounding resistance shall not exceed the value specified in the table below when the auxiliary grounding resistance changes from 500Ω to the value specified in the table:
Auxiliary grounding resistance (Ω) 0 1000 2000 5000 Permissible change expressed as a percentage of the grade index (%) 100 100 100 2003. Other parameters are as follows: Item Content Environmental conditions Temperature (°C) -25～+40 Relative humidity (%) 25～80 Handle speed (r/min) 150 Insulation resistance (MΩ) ≥20 Voltage test (V) 500 Dimensions (l＊b＊h, mm) 172＊116＊135 Weight (kg) 2.5 (4) Measurement: Use a pointer multimeter, resistance range. Alternatively, a grounding resistance tester (also called a megohmmeter) can be used. 1) The resistance between each anti-static test point and the anti-static ground wire is 5~15Ω, ideally 0Ω. However, the actual measured resistance is the sum of the resistance of a 2mm² conductor from the test point to the summing point and the resistance of a 6mm² conductor from the summing point to the test point. This value is approximately 5-15Ω and remains relatively constant. If the measurement result tends towards infinity, it indicates a break in the anti-static ground wire or the measuring wire, which should be repaired promptly.
2) The resistance between the anti-static ground and the equipment ground is composed of the resistance of the anti-static ground wire itself + the resistance of the equipment ground wire itself + the ground resistance between the two ground wires. However, the resistance between the two ground wires is very complex due to factors such as the dryness or wetness of the ground and the influence of ground current, especially the ground current, which changes constantly in magnitude, direction, and frequency, and mainly determines the measurement result. Therefore, only an analog multimeter can be used for measurement, and values ranging from tens of ohms to hundreds of kilohms are considered normal, simply indicating that there is no short circuit or open circuit between the two grounds.