1. Scope of application
AC gapless metal oxide arresters are used to protect the insulation of AC power transmission and transformation equipment from lightning overvoltage and operating overvoltage damage. Suitable for overvoltage protection of transformers, transmission lines, distribution panels, switch cabinets, power metering boxes, vacuum switches, parallel compensation capacitors, rotating electrical machines and semiconductor devices.
2. Characteristics and principles
AC gapless metal oxide arresters have excellent nonlinear volt-ampere characteristics, good response characteristics, no freewheeling, large flow capacity, low residual voltage, strong overvoltage suppression ability, resistance to pollution, anti-aging, not subject to altitude restrictions, simple structure, no gaps, tight sealing, long life, etc.
Under normal system operating voltage, this arrester exhibits a high resistance state and only microampere current passes through it. Under the action of overvoltage and large current, it will show low resistance, thus limiting the residual voltage at both ends of the arrester.
3. Electrical characteristics
The characteristic parameters of AC gapless metal oxide arrester are shown in the table below.
4. Use and maintenance
1. Selection: The lightning arrester should be selected reasonably according to the requirements of the place of use, the electrical parameters in this instruction manual, and the "Guidelines for the Use of AC Gapless Metal Oxide Arrester".
2． Acceptance: Each box of arresters is accompanied by a certificate of conformity and instructions. During acceptance, the appearance should be checked to prevent sharp blades from scratching the jacket. Do not disassemble the upper and lower end caps. During acceptance, the DC 1mA reference voltage should be measured according to the corresponding standards and ordering requirements.
3. Maintenance: To accumulate operational experience, the preventive test cycle is five years. The pre-test items are the leakage current under the DC 1mA reference voltage and 0.75 times the DC 1mA reference voltage. The measured voltage values should meet the corresponding standards and requirements.
4. Installation: The arrester should be fixed on a shell or special bracket close to the protected equipment. Use multi-stranded copper wires with a cross-section of not less than 6 square millimeters. Connect the upper terminal of the arrester to the phase line and the lower terminal to the public ground wire (the ground resistance is not greater than 10 ohms).
5. User ordering instructions
1. This product can be replaced or repaired by our company within three years from the date of shipment, provided that the user abides by the rules of use.
2． If users have special performance requirements, they can come in person, send letters, or call us, and we will manufacture and supply products according to the agreement.
