State-of-the-art microprocessor-based relay protection and automation devices are being widely implemented at the regional substations as a part of the program of modernization and technical upgrading of power facilities owned and operated by Ulyanovsk Distribution Grids, a branch of IDGC of Volga, JSC. Obsolete mechanical relays were replaced with microprocessor-based and electronic devices, such as Sirius-2Л», RS-80М2-14, UZA-10 А.2.Relay protection and automation devices are intended to provide reliable protection for electrical machinery against short-circuit currents and eliminate abnormal operational grid conditions. New microprocessor-based fault-tracking indicator was installed at Maina substation and Maina-Ignatovka 110 kV overhead power transmission line. In case of any line damages, this device will define the damage location and type, disconnecting and isolating the affected section from the entire system virtually in an instant. During refurbishment activities at 110 kV Tsentralnaya substation, new state-of-the-art 110 kV SF6 circuit breaker with microprocessor-based protective relays that meet all up-to-date requirements has been commissioned. According to Vladimir Sevastianov, Head of the Regional Relay Protection and Automation Service, normal operation of the power system is impossible without relay protection and automation devices. Operation of relay protection and automation devices (RZA) is a matter of supreme concern of Ulyanovsk Distribution Grids. Maintenance operations are performed in compliance with the approved maintenance schedule. In Q2 2011, specialists of the Company provided maintenance services for 845 RZA devices, and the planned scope of activities cover 1,655 devices. Reliable operation of relay protection and automation devices results in lower damage levels of equipment and reduced undersupply of energy to the customers under technological failure conditions.