1MRS 750942-MUM
Combined Overvoltage and Undervoltage Relay
Technical Reference Manual
REU 523
5
1. Introduction
1.1. About this manual
The purpose of this manual is to provide the user with thorough information on the
protection relay REU 523 and its applications, focusing on giving a technical
description of the relay.
Refer to the Operator’s Manual for instructions on how to use the
Human-Machine Interface (HMI) of the relay,
also known as the Man-Machine
Interface (MMI),
and to the Installation Manual for installation of the relay.
1.2. The use of the relay
The voltage relay REU 523 is intended for over and undervoltage protection in
medium voltage distribution networks but can also be used for protection of
generators, motors and transformers.
The REU 523 is based on a microprocessor environment. A self-supervision system
continuously monitors the operation of the relay.
The HMI includes a Liquid Crystal Display (LCD) which makes the local use of the
relay safe and easy.
Local control of the relay
via serial communication
can be carried out with a portable
computer connected to the front connector and remote control via the rear connector
connected to the distribution automation system through the serial interface and the
fibre-optic bus.
1.3. Features
• Single or three-phase use
• High-set overvoltage stage with definite-time or inverse definite minimum time
(IDMT) characteristic
• Low-set overvoltage stage with definite-time or IDMT characteristic
• High-set undervoltage stage with definite-time or IDMT characteristic
• Low-set undervoltage stage with definite-time or IDMT characteristic
• Positive-phase-sequence protection
• Ajustable drop-off/pick-up ratio for the low-set stages
• Circuit-breaker failure protection (CBFP)
• Disturbance recorder
• recording time up to 12 seconds
• triggering by a start or a trip signal from a protection stage and/or by a binary
input signal
• records three analogue channels and eight digital channels
• adjustable sampling rate
To Next Page
Loading...
