Its main function is to ensure that the transformer can promptly trip the faulty circuit in case of overload, short circuit, gas relay activation, and other abnormal operating conditions, thereby protecting the main transformer from damage and preventing the expansion. Its main function is to ensure that the transformer can promptly trip the faulty circuit in case of overload, short circuit, gas relay activation, and other abnormal operating conditions, thereby protecting the main transformer from damage and preventing the expansion. Cabinets and devices of relay protection and automation (RPA) manufactured by Radiy are a modern solution for control, automation, protection, monitoring and signaling at power facilities. They are used effectively in the following applications: This equipment is ideal for both newly constructed. ABB's transformer protection relays are used for protection, control, measurement and supervision of power transformers, unit and step-up transformers, including power generator-transformer blocks in utility and industry power distribution networks. In some cases, a user may apply the techniques described in this guide for protecting. This guide focuses primarily on application of protective relays for the protection of power transformers, with an emphasis on the most prevalent protection schemes and transformers. Setting procedures are only discussed in a general nature in the material to follow.