The Role Of Lightning Protection Of CRT Dry Type Transformers
Install lightning arrester protection to prevent lightning overvoltage. For lightning protection of dry-type transformers, seamless metal oxide arresters are set as overvoltage protection to prevent the mains transformers from intruding into high-voltage and low-voltage lines intruding into high-voltage lightning strikes and causing internal insulation damage. The arrester is used to protect dry-type transformers. First, purchase qualified products through the normal route, start operation after strict tests, and install and operate after meeting the operating requirements. The two are to carry out preventive tests on equipment in regular operation, and exchange unqualified products whose leakage current value exceeds the reference value in time. For testing above 100 kVA, the grounding resistance must be within 4Ω. The distribution dry-type transformer below 100 kVA refers to the grounding resistance within 10Ω. If the test value is not within the specified range, extend the grounding wire to increase the grounding body, and take physical and chemical measures to reach the specified value. The resistance of the butt joint is measured twice in April and July every year. The grounding resistance does not exceed the standard due to the falling off of the welding point and the environment.
If the grounding resistance of the dry-type transformer exceeds the reference, the lightning current cannot flow into the ground during a lightning strike. However, if the lightning voltage is applied to the low-voltage side of the distribution dry-type transformer through the ground wire, the reverse boost voltage will be high. Fourth, the installation location is suitable, and the high-voltage arrester is set on the wire near the high-voltage sleeve of the dry-type transformer. So as to ensure that the lightning directly penetrates into the transformer sleeve. Ensure correct operation before lightning waves penetrate dry-type transformers. According to the installation specifications and standard requirements of electrical equipment, prevent blind settings from losing their protective meaning.
