Isolation switch finger pressure

No content provided for translation..Overview

Isolation switches are high-voltage switchgear widely used in power systems due to their large usage volume and extensive application range. As for outdoor isolation switches are...Please provide the Chinese content to be translated..No Chinese content provided.Electrical equipment that operates directly and severely affected by environmental climate conditions in an exposed atmosphere is subject to harsh operating conditions, making it prone to mechanical or electrical failures. Particularly, the contact portions are susceptible to damage from rain, dust, and harmful gases, leading to poor contact and subsequent overheating. The springs providing contact pressure can lose their tension and degrade due to overheating, further exacerbating the overheating of the contacts in a vicious cycle, ultimately causing them to burn out and leading to accidents. During maintenance, there is often a focus on replacing visibly failed or broken springs, but springs with reduced tension are often overlooked. As a result, during subsequent operation, the distribution of current among the contact fingers varies due to differing pressures, with greater variations leading to uneven current distribution. Over time, this can result in poor contact and overheating. The overheating of the contact fingers can lead to a cascade of poor contact throughout the entire contact point. Additionally, many isolation switches allow adjustable contact finger pressure. If the pressure is not adjusted sufficiently during maintenance or if there are differences in the adjustment pressure for each finger, the aforementioned issues can arise.

Currently, the vast majority of maintenance personnel judge the quality of contact of the conductive parts by measuring their loop resistance, believing that if the loop resistance is within the acceptable range, the maintenance work on the conductive parts can be圆满 completed. However, this is not the case. The loop resistance values provided in the product manual are for the entire conductive loop, including the bulk and contact resistances of parts such as terminal blocks, conductive tubes, and contact tips, which have a wide range and considerable margin. They cannot directly reflect the changes in contact resistance and only indicate that the conductive loop is open. Tests have shown that the loop resistance values for both two pairs and four pairs of contact tips are within the acceptable range. Similarly, the pressure of the contact tips and the size of the loop resistance have minimal changes.

Regulations for measuring contact finger pressure are present in various maintenance procedures and standards, with the recommended tool being a spring scale. In practical operations, measuring contact finger pressure at heights is not only inconvenient and inaccurate but also unsafe using a spring scale. In some structures, the contact finger pressure of isolating switches (such as scissor-type) cannot be measured with a spring scale at all. Therefore, the requirement to measure contact finger pressure is merely a piece of paper.

In response to the current maintenance situation of the power supply system, our company has independently developed an intelligent testing instrument for measuring the contact pressure of high-voltage isolator contacts. By simply opening the sensor of the test clamp to simulate the contact, it can display and remember the contact pressure of the contacts at that moment. This effectively solves a major challenge in measuring contact pressure.

ED0307BThe type isolation switch finger pressure tester can also be used by isolation switch manufacturers for finger pressure inspection; altering the shape of the pressure sensor can also measure the finger pressure of circuit breakers.

Two.Key Technical Parameters

Work Environment:-20～40℃，≤80%RH  Atmospheric Pressure86～106kpa

Power Voltage:AC220V±10%  50Hz±10% Or battery power for internal use: ≤20 W

Measurement Range:≤1000 N   Error: ≤1％

Measure diameter (contact gap):5.5mm～90mm Greater90mm( customizable )

Built-in lithium battery, power working time:≥6Hourly ( customizable ).

Charging Method:

a)Charge battery through a dedicated charger connected to the battery charging interface on the panel.

b)PanelAC220VPlug Charging

Sensor Signal Wire Length:10m

Insulation Resistance  ＞2MΩ

Dielectric Strength  Power supply to the casing at industrial frequency1.5KVN/A1Minutes, with no flashovers or arcs.