Do not connect with the external atmosphere, can be used in a more hostile environment

Without insulating oil of the transformer. By type are: ① open type, which is connected with the atmosphere through the body, suitable for clean and relatively dry indoor environment; ② closed, the body has a closed shell, so that do not connect with the external  electri cenergy meter , can be used more hostile environment; ③ mastic, epoxy or other resin casting as insulation, its small size, light weight, easy to install, easy to maintain, no fire and explosion hazard, suitable for high-rise  circuit breakers , subways and other fire safety requirements of high place. Conditions of use of the product, in addition to the general requirements of the same transformer, it must also be installed in a well-ventilated place.