Instrumentation grounding tips

Instrumentation industry grounding is also studied, only the correct grounding can ensure the measurement accuracy and personal and equipment safety. Point out 10 tips for everyone today to help you better ground.

First, the control system AC power should come from a separate system, separate from other equipment and use;

Second, the power supply design should take into account the impact of the initial current, can withstand at least 10 cycles;

Third, the control system AC ground should be built on the isolation transformer or UPS, or in the vicinity;

Fourth, the control system workstation AC power should use a special socket;

5. When connecting the field device power supply with several I/O interface adapters, a barrier bar should be used;

6. The AC power supply of the control system should be supplied by an isolation transformer or UPS;

7. When the AC and DC inputs are connected to the same terminal block, the terminal block must be marked with an appropriate warning label;

Eighth, AC ground wire should be equal to or larger than the current carrying line model;

9. Reserve an additional line or use a terminal box to provide test points.

10. The resistance of the grounding system must be tested to ensure that the grounding meets the requirements of the control system manufacturer's electromagnetic wave tests.

Instrumentation grounding regulations:

1. The instrument grounding system is divided into protective grounding and working grounding. Grounding plays an important role in suppressing interference signals, ensuring measurement accuracy, protecting personal and equipment safety, and ensuring high and stable production.

2. The protective grounding is connected to the electrical network of the device's electrical system. The grounding resistance is generally ≤ 4Ω.

3. The work ground includes signal loop grounding, shield grounding, and intrinsically safe system grounding. The signal circuit grounding and shield grounding are connected to the instrument system grounding network. The grounding resistance accords with the manufacturer's standard. When the intrinsically safe grounding system is independently set, the separate intrinsically safe grounding electrode is connected to the grounding network or other grounding network of the electrical system of the device. Distance ≥5.0m, grounding resistance ≤1Ω or in compliance with manufacturer's standards.

4. The cable shielding should be grounded at one end of the control room and connected to the grounding busbar of the instrumentation equipment. The signal shielding layer should be continuous throughout the cable connection.

5. The grounding wire adopts stranded copper stranded wire and is connected by crimping.

6. The color of the insulating sheath of the grounding wire should be yellow-green, and the two ends should have signs indicating the grounding type.