Conventional AC test transformers are especially designed to testing objects of medium capacitance. These system are particularly suited for tests requiring stable voltage even if the load changes under voltage (corona, wet & pollution tests) or when the load in inductive (inductive voltage transformer).

Tank type AC test transformer is situated in an enclosed and earthed metal tank. This transformer is oil-cooled and can be optionally equipped with a suitable bushing (oil to air or oil to SF6). It's also qualified for continuous duty, long duration tests.

The capacity of tank type test transformer is larger than cylinder type, it can be used for high voltage pollution tests, test line and capacity required continuous test. This design is most suitable for using outdoor, and therefore is recommended to use in areas with poor climatic conditions, especially in high humidity areas and tropical countries.