The zinc oxide arrester tester is an instrument used to test the electrical parameters of the arrester. It can be used for live testing at the test site and for power outage maintenance in the laboratory. What are the characteristics of zinc oxide arrester tester? Let’s introduce them to you below.
1. Large traffic
The current performance is mainly reflected in the ability of the arrester to absorb various lightning overvoltages, power frequency transient overvoltages and operating overvoltages. At present, the capacity of zinc oxide arresters meets or even exceeds the national standard requirements. Indicators such as line discharge level, energy absorption capacity, 4/10ns large current impulse tolerance, and 2ms square wave flow capacity have all reached high domestic levels.
2. Excellent protective properties
Zinc oxide surge arresters are used to protect various electrical equipment in power systems from overvoltage damage to electrical products and have good protection properties. Due to the excellent nonlinear volt-ampere characteristics of the zinc oxide valve, only a few hundred microamps of current pass through it under normal operating voltage. It is easy to design a gapless structure, which makes it have the characteristics of good protection performance and light weight. Small weight and size. When overvoltage invades, the current flowing through the valve plate increases rapidly, limiting the overvoltage amplitude and releasing the overvoltage energy. Afterwards, the zinc oxide valve plate returns to the high-resistance state, allowing the power system to operate normally.
3. Good sealing performance
The arrester components are made of high-quality composite coatings with good aging performance and good air tightness. Measures such as controlling the compression of the sealing ring and applying sealant are adopted. The ceramic coating is used as the sealing material to ensure reliable sealing and stable performance of the arrester.
4. Mechanical properties
The mechanical properties are measured from three aspects: seismic force, wind pressure acting on the arrester, and allowable tension of the conductor at the top of the arrester.
5. Good decontamination performance
Gapless zinc oxide arresters have high pollution resistance. The specific creepage distance levels stipulated in the national standard are:
1. Secondary medium pollution area: specific creepage distance 20mm/kV
2. Category III heavy pollution area: creepage distance 25mm/kV
3. Category IV extremely heavy pollution area: specific creepage distance 31mm/kV
6. High operational reliability
The reliability of long-term operation depends on the quality of the product and the reasonable selection of the product. There are three main factors that affect the quality of its products. One is the rationality of the overall structure of the arrester. Second, the volt-ampere characteristics and aging resistance of zinc oxide valves; third, the sealing performance of the arrester.
7. Power frequency tolerance
Due to reasons such as single-phase grounding, long-line capacitance effect and load shedding in the power system, the power frequency voltage will rise or high-amplitude transient overvoltage will occur. The arrester has a certain period of time to withstand a certain rise in power frequency voltage.
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