How to calculate partition resistance? Detailed explanation of partition resistance calculation methods and steps

Electrical Design and Electrical Safety Areas, DivisionresistanceThe calculation is an important link to ensure the safe and stable operation of the system. Zoning resistance is mainly used to evaluate the resistance values ​​of different areas in the grounding system of electrical equipment to determine whether the grounding system meets safety standards. This article will introduce the calculation method of partition resistance in detail to help engineers and technicians accurately master calculation skills and improve the safety performance of electrical systems.

Zone resistance refers to the ground resistance value divided according to different areas or zones in a grounding system. Reasonable division of zone resistors can effectively analyze the overall performance of the grounding system, discover potential grounding fault points, and ensure the normal operation of electrical equipment and personal safety.

Zone resistance is usually measured and calculated. The basic formula is:

\[ R = \frac{U}{I} \]

Among them, R is the resistance value, U is the voltage, and I is the current. In the calculation of zone resistance, it is necessary to combine the specific measurement method and the grounding system structure to reasonably select the voltage and current measurement points.

The zoning should be based on the structure of the grounding body, geological conditions and the layout of electrical equipment. General principles include:

Keep the resistance uniform in each area;

Avoid excessive resistance differences between partitions;

Easy to measure and maintain.

Commonly used methods for measuring partition resistance include double clamp method, three-point method and four-point method. Choosing an appropriate measurement method can improve measurement accuracy and reduce the impact of environmental interference on the results.

Step 1: Determine the partition range and clarify the measurement points;

Step 2: Use appropriate measuring instruments to measure voltage and current;

Step 3: Based on the measured data, use basic formulas to calculate the resistance of each zone;

Step 4: Compare the calculation results with the standard requirements to determine whether they meet the specifications.

Soil resistivity is an important factor affecting zone resistance. Different soil types have different resistivities. When calculating the zone resistance, the soil resistivity should be used for correction to ensure the accuracy of the calculation results.

In a complex grounding system, multiple zone resistances interact with each other. Through comprehensive analysis of the resistance of each zone, the safety performance of the entire grounding system can be evaluated and abnormal conditions can be discovered in a timely manner.

不合理划分分区导致计算误差；

测量时环境干扰未排除；

忽视土壤电阻率变化；

设备连接不良影响测量结果。

以某工业厂区接地系统为例，通过合理分区和测量，计算出各分区电阻值，最后优化接地设计方案，提高系统整体安全性。

分区电阻的计算是电气接地设计中不可忽视的重要工作。通过科学划分分区、合理选择测量方法、准确计算电阻值，能够有效提升接地系统的安全性和稳定性。掌握分区电阻的计算方法，不仅有助于满足安全规范要求，还能为电气设备的正常运行提供保障。希望本文对您理解和应用分区电阻计算有所帮助。