Description+ The SIPROTEC 7SA87 distance protection has been designed specifically for the protection of lines. With its modular structure, flexibility and the high-performance DIGSI 5 engineering tool, the SIPROTEC 7SA87 device offers future-oriented solutions for protection, control, automation, monitoring, and Power Quality- Basic. Main function Distance Protection Interoperability of SIPROTEC 4 and SIPROTEC 5 line protection devices Tripping 1-pole and 3-pole, minimum tripping Inputs and out- 12 predefined standard variants with 4/4 puts or 8/8 current transformers/voltage trans formers, 5 to 31 binary inputs, 8 to 46 binary outputs Hardware flexibi- Flexibly adjustable I/O quantity structure lity within the scope of the SIPROTEC 5 modu Housing width 1/3 x 19 inch to 2/1 x 19 inch Applications • Detection and selective 1 -pole and 3-pole tripping of short circuits in electrical equipment of star networks, lines with infeed at one or 2 ends, parallel lines, and open-circuited or closed ring systems of all voltage levels • Detection of ground faults in isolated or arc-suppres-sion-coilground systems in star, ring, or meshed arrangement • Serial protection communication with SIPROTEC 5 and SIPROTEC 4 devices over different distances and physical media, such as optical fiber, two-wire connections, and communication networks • Backup protection for differential protection devices of all kind for lines, transformers, generators, motors, and busbars • Phasor Measurement Unit (PMU) • Detection and recording of power-quality data in the mediumvoltage and subordinate low-voltage power system Functions DIGSI 5 permits all functions to be configured and combined as required. • Minimum tripping time: 9 ms • 6 independent measuring loops (6-system distance protection) • Several distance-protection functions can be selected: Classic, reactance method (RMD), impedance protection for transformers • Directional backup protection and various additional functions • Detection of ground faults of any type in compensated or isolated electrical power systems using the following functions: 3I0>, V0>, transient ground fault, cos 0, sin 0, dir. detection of intermittent ground faults, harmonic detection, and admittance measurement • Ground-fault detection using the pulse-detection method • Adaptive power-swing blocking, out-of-step protection • Detection of current-transformer saturation for fast tripping with high accurac

• Fault locator plus for accurate fault location with in-homogenous line sections and targeted automatic overhead-line section reclosing (AREC) • Arc protection • Automatic frequency relief for underfrequency load shedding, taking changed infeed conditions due to decentralized power generation into consideration • Power protection, configurable as active or reactive-power protection • Directional reactive-power undervoltage protection (QU protection) • Detection of current and voltage signals up to the 50th harmonic with high accuracy for selected protection functions (such as thermal overload...