The paper presents the results of our experiments with novel devices, which may open a new path for advanced applications by using continuous, perfectly closed superconducting YBCO loops. With this solution we wanted to examine whether it is possible to create novel fault current limiter, 3-phase self-limiting transformer. We considered the significance and efficiency of the perfect closed loop made from YBCO wire. The used superconducting wire was produced at SuperPower, Inc. in New York, USA. Type: SF 12050.