Zinc Oxide Lightning Arrester Tester Surge Arrester On-site Testing Equipment
A lightning arrester (alternative spelling lightning arrestor) (also called lightning isolator) is a device, essentially an air gap between an electric wire and ground, used on electric power transmission and telecommunication systems to protect the insulation and conductors of the system from the damaging effects of lightning. The typical lightning arrester has a high-voltage terminal and a ground terminal. When a lightning surge (or switching surge, which is very similar) travels along the power line to the arrester, the current from the surge is diverted through the arrester, in most cases to earth.
Functionalities of the tester
The zinc oxide surge arrester is a lightning arrester with excellent protective performance. It utilizes the good nonlinear voltage-current characteristics of zinc oxide to keep the current flowing through the arrester extremely small (microamps or milliamps) under normal operating voltage. When subjected to overvoltage, the resistance sharply decreases, dissipating the energy of the transient voltage and achieving the protection effect. The key difference between this type of surge arrester and traditional ones is that it doesn't have a spark gap; instead, it utilizes the nonlinear characteristics of zinc oxide for current leakage and interruption.
Troubleshooting
Thermal breakdown of zinc oxide surge arrester:
The ultimate cause of thermal breakdown in a zinc oxide surge arrester is when the heat generated exceeds the heat dissipation capability. The heat generation in the zinc oxide valve element depends on the current and voltage applied (current being the active component flowing through the valve element).
Moisture ingress in zinc oxide surge arrester:
Poor sealing can lead to moisture ingress within the surge arrester, or during installation, moisture may penetrate the interior. This can cause an increase in the total current under voltage. When moisture reaches a certain level, discharge may occur along the surface of the zinc oxide valve element or the inner wall of the porcelain housing, leading to an arrester explosion. The increase in total current due to moisture ingress in the zinc oxide surge arrester is caused by resistive leakage current increase. The extent of moisture ingress can be inferred by measuring the change in the angle. Therefore, it is recommended to store the surge arrester in a well-ventilated and dry place after each test to prevent further moisture ingress.
Packing list
No. |
Item |
Unit |
Quantity |
1 |
Host |
Piece |
1 |
2 |
Unit |
Piece |
1 |
3 |
Accessory case |
Piece |
1 |
4 |
current wire |
Piece |
1 |
5 |
voltage wire |
Piece |
1 |
6 |
Communication cable |
Piece |
1 |
7 |
Wireless antenna |
Piece |
2 |
8 |
Charger |
Piece |
2 |
9 |
U disk with upper computer software |
Piece |
1 |
10 |
User manual |
Piece |
1 |
11 |
Product certificate |
Piece |
1 |
12 |
Test report |
Piece |
1 |
13 |
Fuse |
Piece |
6 |
Optional
14 |
Sensor board (optional) |
Set |
1 |
15 |
Current clamp (optional) |
Piece |
3 |