Description The SIPROTEC 7UT85 transformer differential protection device has been designed specifically for the protection of two-winding transformers (2 sides). It is the main protection for the transformer and contains many other protection and monitoring functions. The additional protection functions can also be used as backup protection for subsequent protected objects (such as short cables lines, reactance coil (shunt reactors)). With its modular structure, flexibility, and the high-performance DIGSI 5 engineering tool, SIPROTEC 7UT85 offers futureoriented solutions for protection, control, automation, monitoring, and Power Quality - Basic. Main function 1 differential protection function (standard or auto transformer) with additional stabilization; up to 2 restricted ground-fault protection functions Interoperability of SIPROTEC 4 and SIPROTEC 5 line protection devices when using the line differential protection function in the 7UT85, 86, 87 Usable measur- 5 x 3-phase current measuring points, 5 x 1-ing phase current measuring points, 5 x 3-phase points and 5 x 1 -phase voltage measuring points; ex pandable to 3 sides Inputs and 2 predefined standard variants with 8 current outputs transformers, 7 to 19 binary inputs, 7 to 23 bi nary outputs Hardware flexibi- Flexibly adjustable and expandable I/O quan-lity tity structure within the scope of the SIPRO- TEC 5 modular system Housing width 1/3 x 19 inch to 2/1 x 19 inch Applications • Protection of special transformers (phase shifters, FACTS and converter transformers, electric arc furnace transformers, HVDC transformers) • As backup protection for motor and generator differential protection applications • For the protection of short cables and lines SIPROTEC 7UT85 Transformer Differential Protection (1/2 device = standard variant P1) • Voltage control for two-winding and three-winding transformers with parallel control • As additional line protection function such as distance and line differential protection Functions With the Disconnection of measuring points function, you can disconnect the I-3ph measuring point from a protection function group. If the measuring point has been disconnected, you can perform any work without influencing the work of the protection functions that have been assigned to the measuring point. After disconnection of the measuring point, the differential protection, for example, stops taking the measured values of this measuring point into account for calculating the differential current. DIGSI 5 permits all functions to be configured and combined as required. • Transformer differential protection for two-winding transformers with versatile, additional protection functions; expandable to 3 windings • Transformer differential protection for phase-angle regulating transformers of the single core type and special transformers • Universal usability of the permissible measuring points • Applicable from average up to extra-high voltage

Protection of standard power transformers, auto transformers, short lines, cables, shunt reactors and motors Typical properties of a transformer differential protection such as flexible adaptation to the transformer vector group, control of inrush and overexcitation processes, safe behavior in case of current transformer saturation with different degrees of saturation Adaptive adaptation of the operate curve to the transformer tap position Increased sensitivity with near-neutral-point ground faults through a separate restricted ground-fault protection Additional current and voltage inputs can...