VLF hipot —very low frequency hipot — is an AC high potential instrument used for testing the dielectric strength of insulating materials at 0.1 Hz or lower. Instead of having to perform DC testing because high potential test equipment that operates at power system frequency are large, heavy and therefore not very portable, VLF high potential testing makes testing cables and electrical apparatus in the field more practical and economical.
The Omicron TESTRANO 600 Three-phase Power Transformer Test System is a portable, three-phase power transformer test system, which supports most common electrical tests on power transformers for routine and diagnostic testing onsite or during factory acceptance tests (FAT).
Vacuum interrupters offer several advantages over older arc extinguishing contact systems found in circuit breakers and other types of switch gear. Vacuum breakers have long mechanical and electrical operating life and excellent switching capabilities. These sealed bottles create an envelop of negative pressure that is not conducive to the formation or sustaining of electrical arcs when contacts operate under load. Additionally, since the contacts are encased in a bottle, they are not exposed to the contaminants found in many of the environments where they are utilized. They are virtually maintenance-free and have operation counts from 5000 to 1000000 before they reach their end of life. However, even if they have long operating lives, vacuum bottles should be tested for defects to avoid problems in the electrical system.