How to correctly choose and install metal oxide arresters

1　 Metal Oxide Lightning Arrester in 10kV Distribution Network

The main function of lightning arrester is to protect electrical equipment from lightning intrusion wave overvoltage and operating overvoltage from damage to the insulation of its equipment.

2　 Matters needing attention in installation, use and maintenance, cold-shrinkable cable terminal.

(1) The nameplate should be calibrated before installation, and the system rated voltage of the arrester should be consistent with the system voltage at the installation point;

(2) The arrester is fixed on the bracket, the upper terminal is connected with the high-voltage line, and the lower terminal must be reliably grounded;

(3) The arrester cannot be used as a load-bearing insulator, and should be installed as close to the protected equipment as possible to reduce the influence of distance on the protection effect;

(4) The terminal arrester should be installed after the drop-out fuse to protect it when it is broken. A low-voltage arrester should be installed on the low-voltage side of the transformer to prevent the transformer from being damaged by the overvoltage caused by the positive and negative conversion;

(5) When using lightning arresters, pay attention to the ambient temperature of the place where they are used. Metal oxide arresters are not suitable for installation in places with vibration or severe contamination and places with severe corrosive gas;

(6) Preventive tests should be done before the composite jacket zinc oxide arrester is put into operation and after every two years of operation;

(7) The arrester is sealed with a stainless steel bottom cover. After it is put into operation, preventive tests should be carried out every 5 years. When measuring the leakage current, 0.75 times the DC 1mA reference voltage should be applied on both sides of the arrester (AC pulsation is not more than ±1.5%) , Read the current value through the arrester, that is, its leakage current, and the leakage current is required to be no more than 50 microamperes. Lightning arrester manufacturers.

(8) The grounding of the arrester shall comply with the requirements of grounding regulations.

3　Problems that should be paid attention to in the selection of lightning arresters

First of all, pay attention to the place of use in the selection. Different places have different models of arresters.

Power distribution type: to protect the corresponding voltage level transformers, box-type transformers, cable heads and other related power distribution equipment from damage from the atmosphere and operating overvoltages, it is advisable to choose "HY5WS" metal oxide arresters.

Power station type: to protect AC electrical equipment in power plants and substations from atmospheric overvoltage and operating overvoltage damage, you can choose "HY5WZ" or "HY10WZ" type;

Motor type: limit the overvoltage generated when the vacuum circuit breaker or the low oil circuit breaker is switched on and off the motor or generator, and protect the motor from the damage of the operating overvoltage. Choose "HY2.5WD", and choose "HY5WD" for the protection of the generator. ；

Capacitor type: To suppress the overvoltage generated by the operation of the vacuum circuit breaker or the less oil circuit breaker to protect the capacitor bank from the damage of the operation overvoltage, select the "HY5WR" type.

In short, when using lightning arresters, you should choose products from regular manufacturers, carefully understand their performance and use, and install them in strict accordance with the requirements of the relevant electrical installation regulations.

Yichang Hengyuan Technology Co., Ltd. is a professional manufacturer of European-style cable connectors, plug connectors, cable branch boxes, American elbow connectors, high-voltage vacuum circuit breakers, high-voltage load switches, lightning arresters, zinc oxide arresters, tank arresters, overvoltage protectors, Counters, monitors, heat-shrinkable cable accessories, cold-shrinkable cable accessories, T-shaped heads, wall bushings, European cable accessories, American cable joints, transformer neutral point protection devices, fuses, isolating switches, PT cable heads, elbows Manufacturers of type cable joints, 10kV outdoor terminals, switch cabinets, cable intermediate joints, cable accessories and other products