The combined instrument transformer offers the station designer the ability of being able to accommodate the current transformer and the voltage transformer in one free-standing unit. This allows optimum use of substation space while yielding cost savings by elimination of one set of mounting pads and support structures. In addition, installation time is greatly reduced.

Combined Instrument Transformers are commonly used in the electrical power industry when the space auf the substation is limited and are available with either oil or SF₆  dielectric systems.