Why the red light of the lightning arrester online monitor is on


Publish Time:

2021-03-25

Lightning arresters will gradually age under the action of high power frequency and high voltage for a long time. During operation, breakdown and damage may occur, and the protection characteristics will decrease, which will have extremely serious consequences. In order to ensure the safe operation of MOA arresters, zinc oxide arresters must be carried out. Strict monitoring.

Why the red light of the lightning arrester online monitor is on

Lightning arresters will gradually age under the action of high power frequency and high voltage for a long time. During operation, breakdown and damage may occur, and the protection characteristics will decrease, which will have extremely serious consequences. In order to ensure the safe operation of MOA arresters, zinc oxide arresters must be carried out. Strict monitoring.

At present, the method of monitoring zinc oxide surge arresters adopts the surge arrester online monitor to realize online monitoring. Its working principle is under normal operating voltage. The change of the leakage current through the arrester is measured by an ammeter. When a strong operating current flows, it will leak The current measurement loop is transferred to the counter loop, and the action of the discharge counter uses the energy of the action current to record the number of actions. However, because the arrester online monitors are all installed at the height of the tower, it is difficult to read the arrester parameter meter and overhaul. The existing method is to periodically rotate the arrester, and check the tower during the annual standard overhaul to clean the arrester and grounding device. This method has high replacement costs for lightning arresters, high labor intensity, and a long period of power outage required to be applied for, which is not conducive to the economic and stable operation of the transmission line. Therefore, an "online, real-time, and reliable" monitoring method must be adopted.

Leakage current refers to the current flowing through the arrester valve core after the arrester is connected to the system. Because lightning arresters are usually similar to insulators, the current is quite small when there is no overvoltage. Approximately no more than 1MA. If it becomes larger, it means that the performance of the valve plate in the arrester core body has decreased. The arrester online monitor has an ammeter, which has green, yellow and red ranges. The pointer in the green range indicates good performance, and the yellow range indicates that the leakage current is slightly larger. , The red range indicates that the arrester needs to be replaced. Because the arrester is a fully enclosed overall device, there is generally no such thing as maintenance. Can only be replaced with a new one. The arrester monitor monitors the leakage current when the arrester is working. When the leakage current exceeds the specified value, the red light will be on. This shows that the performance of the arrester does not meet the requirements, and the leakage current is too large. Generally consider replacing the arrester.