The TX-121 Isolation Transformer is used with the Tx range of transmitters to apply a low frequency signal across shorted phases on LV cables to enable location of phase to phase faults. (Rated for connection to CAT IV mains circuits up to 230V phase-to-neutral. Maximum phase to phase voltage differential: 3V rms at 50/60Hz).
For more information of its application, please refer to the Application Note.