IEEE Std 1818-2017 pdf download – IEEE Guide for the Design of Low- Voltage Auxiliary Systems for Electric Power Substations.
panelboard: A single panel or group of panel units designed for assembly in the form of a single panel, including buses and automatic overcurrent devices, and equipped with or without switches for the control of light, heat, or power circuits; designed to be placed in a cabinet or cutout box placed in or against a wall, partition, or other support; and accessible only from the front. (Adapted from the NEC.) See also: switchboard. period: An interval of time in the battery duty cycle during which the current (or power) is assumed to be constant for purposes of cell-sizing calculations. rated capacity (lead-acid): The capacity assigned to a cell by its manufacturer for a given discharge rate, at a specifed electrolyte temperature and specifc gravity, to a given end-of-discharge voltage. remote terminal unit (RTU): A piece of equipment located at a distance from a master station to facilitate monitoring and control the state of outlying power equipment and to communicate the information back to the master station or host. separately derived system: A wiring system whose power is derived from a generator, transformer, or converter windings and has no direct electrical connection, including a solidly connected grounded circuit conductor, to supply conductors originating in another system. series rated system: Each protective device needs to only be rated for the available fault current at its terminals. station service voltage transformer (SSVT): A transformer that supplies power from a station high-voltage bus to the station auxiliaries and also to the unit auxiliaries during unit startup and shutdown, or when the unit auxiliaries transformer is not available, or both. switchboard: (A) A large, single-panel, frame, or assembly of panels on which are mounted, on the face, back, or both, switches, overcurrent and other protective devices, buses, and usually instruments. Switchboards are generally accessible from the rear as well as from the front, and are not intended to be installed in cabinets. (Adapted from the NEC.