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High and low voltage electroscope is a special safety tool used to check whether electrical equipment, appliances, and wires are live. When the power is disconnected for maintenance each time, it must be used to verify that the equipment is indeed de-energized before proceeding with work.
Precautions for voltage testing with high and low voltage electroscope:
1. During voltage testing, there should be 2-3 workers, with 1 operator and 1 supervisor/assistant.
2. Complete the work ticket procedures.
3. Carefully verify the line name, pole number, or equipment name and number.
4. Before use, confirm that the voltage level of the electroscope matches the voltage level of the equipment or line being tested. Using an electroscope with a lower voltage rating than the equipment's rated voltage poses a danger to personnel. Conversely, using an electroscope with a higher voltage rating may lead to misjudgment, also threatening personal safety.
5. Before and after voltage testing, test the electroscope on a live equipment to verify it is functioning properly.
6.During voltage testing, the electroscope should be gradually brought close to the live part until the neon lamp lights up; do not directly touch the live part.
7. When testing overhead power lines, test low voltage first, then high voltage; test the near side first, then the far side.
8. During voltage testing, do not attach a ground wire to the electroscope to avoid the ground wire touching live equipment and causing a ground short circuit or electric shock. If testing on wooden poles or wooden structures where indication is not possible without grounding, a ground wire may be added to the electroscope.
9. Voltage testing should be performed phase by phase. When testing circuit breakers or disconnectors in the open position, both sides of each phase should also be tested.
10. For equipment with large capacitance, such as long overhead lines, cable lines, and phase-shifting capacitors, due to the large amount of residual charge, it may not be easy to discharge quickly. Therefore, if voltage testing is performed immediately after power-off, the electroscope may still light up. In such cases, wait a few minutes before testing again until the electroscope indicates no voltage. Never rely on experience; when the electroscope indicates voltage, thinking it is due to residual charge and blindly performing grounding operations is very dangerous.
11. When testing high voltage, wear insulating gloves. The telescopic insulating rod of the electroscope should be fully extended. During testing, hold the handle and do not exceed the guard ring. Maintain a safe distance from the equipment being tested. Do not perform outdoor direct voltage testing in snowy or rainy weather.
12. Before each use, carefully inspect the insulating parts for dirt, damage, or cracks; check whether the neon bulb is damaged or malfunctioning.
13. High voltage electrical equipment should be tested every six months.
Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.
