Introduction; Rex 521 Protection Relay - ABB REX 521 Operator's Manual

REX 521
2.
2.1.
8
Protection Relay
Operator's Manual

Introduction

REX 521 protection relay

The protection relay REX 521 is designed for protection, control, measuring and
supervision in medium voltage networks. Typical applications include incoming and
outgoing feeders as well as substation protection. The protection relay is provided
with energizing inputs for conventional current and voltage transformers. Also a
hardware version with inputs for current and voltage sensors is available.
The protection relay is based on a multiprocessor environment. The HMI including
an LCD (liquid chrystal display) with different views makes the local use easy and
informs the user via indication messages. Modern technology is applied both in
hardware and software solutions.
The REX 521 is part of the substation automation concept for distribution
automation and extends the functionality and flexibility of the concept.
1MRS 751107-MUM