Voltage protection relay SIPROTEC 7SK8 series

frequencyoverloadpower

The SIPROTEC 7SK80 and SIPROTEC 7SK81 are a multi-functional motor protection relays. They are designed for protection of asynchronous motors of all sizes. Features The SIPROTEC 7SK80 features “flexible protection functions”. Up to 20 additional protection functions can be created by the user. Therefore protection of change for frequency or reverse power protection can be realized, for example. The relay provides circuit-breaker control, further switching devices and automation functions. The integrated programmable logic (CFC) allows the user to add own functions, e.g. for the automation of switchgear (interlocking). The user is also allowed to generate user-defined messages. Hardware •4 current transformers •0 / 3 voltage transformers •3 / 7 binary inputs (thresholds configurable using software) •5 / 8 binary outputs (2 changeover) •0 / 5 RTD inputs •1 life contact •Pluggable current and voltage terminals. Functions •Definite and inverse time-overcurrent protection (phase/ground) (50, 50N, 51, 51N) •Directional time-overcurrent protection, ground (67N) •Directional overcurrent protection, ground (defi-nite/inverse)(67Ns, 50Ns)) •Displacement voltage, zero-sequence voltage (59N) •Trip-circuit supervision (74TC) •Undercurrent monitoring (37) •Temperature monitoring (38) •Thermal overload protection (49) •Load jam protection (51M) •Locked rotor protection (14)