Abb manufactures a wide range of current transformers that are used transform high currents to standardized values for control equipment as relays and meters. Being a part of that gas insulated current transformer tg is a transformer in which cores and secondary windings are located inside the head of the transformer. The high voltage insulation is fully obtained with sf6 gas instead of paper and oil. Salient features are as follows:
1 the dielectric quality is no longer depending on long and complex treatments or delicate checks during the equipment`s lifetime.
2 partial discharge measurements are not necessary as the only piece of solid insulation is the outer porcelain or polymeric envelope.
3 the probability of internal discharge is none, due to insulation coordination with gaseous dielectric medium.
4 this is a device having a preset breakage protects the ct against possible over-pressure.
5 the internal insulation can be continuously monitored by means of a pressure gauge fitted with alarm and/or trip contacts in case of gas pressure decrease or increase.
