Surge Arrester Monitoring Guidelines: Abnormal Increase In Leakage Current Reading During Operation

In power system maintenance, monitoring equipment status is a core element in ensuring stable grid operation. During routine inspections, technicians frequently encounter situations where the operating parameters of the lighting arrester 33kv device deviate from the normal range.

Potential Factors for Rising Resistive Current in Surge Arresters

When a linear increasing trend is observed in the lightning arrester 20 kv reading, deterioration of the internal varistor is often the inducing factor. After prolonged exposure to power frequency voltage and lightning strikes, the nonlinear characteristics of the zinc oxide varistor undergo irreversible changes. This physical degradation directly leads to increased power loss.

Moisture intrusion is also a significant contributing factor. If minute cracks appear in the sealing structure, external moisture enters the cavity, causing dampness on the surface of the internal insulation components. In this state, insulation resistance decreases significantly, and leakage current exhibits a clear stepwise increase.

Classification and Diagnosis of Anomalies in Monitoring Data

For current changes captured by the lightning arrester 22kv device, a comprehensive assessment considering environmental factors is necessary:

• Ambient Humidity Influence: In high humidity conditions, the conductivity of the contaminant layer on the porcelain bushing surface increases, leading to artificially inflated external leakage current readings.
• Power Grid Voltage Fluctuations: Increased operating voltage shifts the operating point of the zinc oxide valve plate upwards, causing changes in the resistive current component.
• Harmonic Interference Analysis: Harmonic currents in the system are superimposed on the fundamental frequency, resulting in an increase in the total current reading on monitoring instruments.

The evolution of electric current caused by internal moisture

lightning arrester 24kv Internal moisture is a process of quantitative change leading to qualitative change. Initially, moisture adheres only to the support rod or the side of the valve plate, resulting in a small increase in leakage current, which is usually difficult to detect with conventional instruments. As moisture accumulates, partial discharge phenomena increase, and the current waveform becomes distorted.

In the middle stage, the heat generated in the damp areas cannot dissipate in time, further accelerating the decomposition of the insulation material. At this point, the leakage current not only increases significantly, but its resistive component proportion also far exceeds the standard limit. If live-line testing or power-off testing is not performed in time, the equipment may face the risk of thermal collapse.

Maintenance Recommendations and Data Review Process

When handling data anomalies in lightning arrester 24kv 10ka devices, multi-dimensional data comparison should be prioritized. By comparing the current differences between the three phases in the same group, the influence of systemic voltage fluctuations can be initially ruled out.

Technicians should use infrared thermography to observe whether there are localized hot spots on the casing. For units suspected of being faulty, AC reference voltage and resistive current tests should be performed. Regularly cleaning the surface of ceramic components can reduce the interference of external factors on monitoring results.