Areva MiCom P120, Technical Manual

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P12x/EN AP/A96 Application Guide
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MiCOM P120/P121/P122/P123
1.2 MiCOM Overcurrent Relays
MiCOM relays are a range of products from AREVA T&D using the latest digital technology.
The range includes devices designed for application to a wide range of power system plant
equipment such as motors, generators, feeders, overhead lines and cables.
Each relay is designed around a common hardware and software platform in order to
achieve a high degree of conformity between products. One product among this range is the
overcurrent relay.
MiCOM P120, P121, P122 and P123 relays have been designed to provide higher
functionality in terms of protections, measuring, automatic operation and order control. They
can be applied to industrial and distribution network applications, as well as in high voltage
and extremely high voltage protection applications.
They can operate in networks with neutral earthed by impedance, by resonant system such
as Petersen coil, in insulated system and in system with neutral earthed.
The protection functions can be used associated with the blocking feature in order to
optimise the performance of the protection schemes, thus reducing operating times.
The earth and phase protection functions include instantaneous and time delay information.
The delay time for the first and second stage for phase and earth fault protections can be
chosen to be in definite or inverse delay time (IEC, ANSI/IEEE, CO, RI ,RECT or RXIDG).
This wide choice of characteristics of triggering times makes it possible to easily integrate
these relays to an existing protection scheme, irrespective of other relays already installed
on the network.