Grounding issues with on-site instruments

When designing the grounding scheme for field instruments, the most reasonable approach generally includes the following key points: 1. Regarding the type of grounding, an appropriate method should be selected based on the operating principle of the equipment and the environmental conditions. For example, protective grounding, functional grounding, antistatic grounding, etc. 2. The ground resistance should be kept as low as possible to ensure that in the event of a fault causing leakage current, the current can be quickly directed into the ground, thereby preventing electric shock to people and damage to the equipment. 3. The grounding location of the equipment should be considered; generally, the common grounding point of the equipment’s metal enclosure or internal electronic components should be chosen. 4. The grounding wire should be made of high-quality conductive material, and its diameter should be large enough to ensure it does not heat up or burn out under high current conditions. As for the discrepancy between clause 3.1.3 of HG/T20513-2014 and clause 4.1.5 of SH/T3081-2019 that you mentioned, I believe it may apply to different situations or types of equipment; not all field instruments require grounding. Whether grounding is actually necessary depends on the working principle of the instrument, its operating environment, as well as the relevant industry standards. If, during the on-site safety inspection, experts suggest that the instruments on site need to be grounded, then actions should be taken in accordance with the actual conditions and the experts’ recommendations. If you have any questions or are unsure, you can also consult the relevant departments responsible for formulating these standards directly. .

Follow the standard with the higher requirements. Experts will definitely insist on grounding; otherwise, they will issue a notice for corrections after their inspection, and no matter what you explain to them, they won’t listen.

May I ask: is it necessary to install new grounding flat bars on site?

When designing and implementing a grounding scheme, whether it is necessary to install new grounding flat bars on site depends on various factors. First, it is necessary to determine whether the existing grounding system can meet the requirements for instrument grounding. This includes checking whether the ground resistance meets the requirements; if it is too high, it may be necessary to install new grounding flat bars. Secondly, the condition of the existing grounding system’s components must be taken into account; if the number, location, or arrangement of the grounding strips in the original system is not ideal or if it is not possible to serve all instruments, then new grounding strips need to be installed. Furthermore, considering the current usage of the existing grounding system, if it is already carrying too many devices, it may not be able to meet the grounding requirements of new devices; in such cases, new grounding flat bars are also needed. Finally, if your new device has special requirements, such as the need for a separate ground connection, then it may also be necessary to install new grounding flat bars. In all cases, it is essential to check the equipment’s user manual and any standards or rules related to the equipment. If necessary, seek advice from electrical engineers or other relevant experts. .