Isolation switchgear contact clamping force tester/precision sensor

One Overview

GSKGY-3000 Isolation Switch Contact Pressure Tester - Isolation switches are the most widely used high-voltage switchgear equipment in power systems. Due to the outdoor isolation switch being*Electrical equipment that operates in the atmosphere and is most directly and severely affected by environmental and climatic conditions has harsh operating conditions and is prone to mechanical or electrical failures. Especially the contact part of the touch finger is easily invaded by rainwater, dust, and harmful gases, resulting in poor contact and heating. The spring that provides pressure to the touch finger will anneal due to heating, causing the pressure to decrease. This further leads to a vicious cycle of heat generation and ultimately burns out the touch finger, causing accidents. During maintenance, attention is often only paid to replacing springs that have obvious failures or fractures, and it is impossible to judge and replace those springs with reduced pressure. As a result, during further operation, the distribution of current in each contact finger will vary due to different pressures, and the greater the difference, the more uneven the current distribution. After long-term operation, poor contact may occur and overheating may occur. The heating of the touch finger can lead to a vicious cycle, where poor contact between one touch finger can spread throughout the entire contact. At the same time, there are many isolation switches with adjustable finger pressure. If the pressure adjustment during maintenance is insufficient or there are differences in the adjustment pressure of each finger, the above phenomenon will also occur.

At present, the majority of maintenance personnel judge the contact quality of conductive parts by measuring their circuit resistance. If the circuit resistance is within the qualified range, the maintenance work of conductive parts can be successfully completed. In fact, the circuit resistance value given in the product manual is the value of the entire conductive circuit, including the body resistance and contact resistance of the wiring terminals, conductive tubes, contact fingers, etc. It has a large range and margin, and cannot directly reflect changes in contact resistance. It can only indicate the conductive circuit path. The experiment shows that the circuit resistance values of two pairs of contact fingers and four pairs of contact fingers are within the qualified range. Similarly, there was no significant change in the resistance value of the small circuit due to high finger pressure.

In various maintenance procedures and standards, there are provisions for measuring the contact pressure of the touch finger. The recommended measuring tool is a spring scale. In practical work, measuring the contact pressure of the touch finger needs to be done at high altitude. Using a spring scale to measure pressure is not only inconvenient, inaccurate, but also unsafe. For some structures of isolation switches, the contact pressure of the touch finger cannot be measured by a spring scale at all (such as scissor type). So, the requirement to measure finger contact pressure is just a piece of paper.

In response to the current maintenance status of the power generation and supply system, our company has developed an intelligent tester for measuring the contact pressure of high-voltage isolation switches. As long as the sensor of the test clamp simulating the contact is opened at each pair of contact positions, it can display and remember the contact pressure of the contact fingers at that time. Effectively solved a major problem in measuring finger pressure.

This instrument can also be used for the inspection of contact finger pressure in isolation switch manufacturers; Changing the shape of the pressure sensor can also measure the finger pressure of the circuit breaker.

II Main technical parameters

Working environment: -20～40 ℃, ≤ 80% RH atmospheric pressure 86-106kpa

Power supply voltage: AC220V ± 10% 50Hz ± 10% or internal lithium battery power: ≤ 20 W

Measurement range: ≤ 1000 N Error: ≤ 1%

Measuring diameter (finger opening distance): 15mm～90mm (customizable)

Built in lithium battery, power supply working time: ≥ 6 hours (customizable).

Charging method: Dedicated charger connected to the lithium battery charging interface on the panel for charging;

Sensor signal line length: 10m

Insulation resistance>2M Ω

The dielectric strength power supply can withstand the 1.5KV power frequency voltage of the casing for 1 minute without flashover or arcing.