Micom P721, Техническое руководство

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P72x/EN IT/C21 Introduction
Page 6/10 MiCOM P721/P723
4. INTRODUCTION TO THE MiCOM P721 & P723 PROTECTIONS
The range of MiCOM protection relays is built on the success of the MIDOS, K and MODN
ranges by incorporating the last changes in digital technology. Relays from the MiCOM P72x
range are fully compatible and use the same modular box concept.
MiCOM P721 and P723 high impedance differential protections provide differential protection
and high impedance differential protection (with P79x high impedance accessory) for
machines, power transformers and busbar installations as well as for other applications
where differential protection is required.
The P721 relay provides simple restricted earth current fault protection. Furthermore, P723
relay is used for 3-phases fault protection.
In addition to its protective functions, each relay offers control and recording features. They
can be fully integrated to a control system so protection, control, data acquisition and
recording of faults, events and disturbances can be made available.
The relays are equipped on the front panel with a liquid crystal display (LCD) with 2 x 16
back-lit alphanumerical characters, a tactile 7 button keypad (to access all settings, clear
alarms and read measurements) and 8 LEDs that indicate the status of MiCOM P721 and
P723 protections.
In addition, the use of the RS485 communication port makes it possible to read, reinitialise
and change the settings of the relays, if required, from a local or remote PC computer loaded
with MiCOM S1 software.
Its flexibility of use, reduced maintenance requirements and ease of integration allow the
MiCOM P72x range to provide an adaptable solution for the problems of the protection of
electric networks.