Features

•Low-set neutral overcurrent stage with definite time or inverse time characteristic
•High-set neutral overcurrent stage with definite time characteristic
•Output relay functions to be freely configured
•Flexible adaptation to different types of application
•Serial interface for connecting the relay to a fibre-optic object bus and substation and network control systems

•Digital display of setting values, neutral current measured, memorized fault values and more
•Continuous self-supervision with auto-diagnostics of hardware and software
•Member of the SPACOM product family and ABB’s Distribution Automation system
•CE marking according to the EC directive for EMC

Application

The relay has two protection stages: a low-set overcurrent stage I0> and a high-set overcurrent stage I0>>. The low-set stage operates with definite-time characteristic or with inverse-time characteristic, while the high-set stage operates with definite time characteristic only. The earth-fault relay is used both as primary and back-up earth-fault protection relay for feeders, transformers, generators and motors. The relay can be configured to cooperate with a residual voltage relay used for blocking/deblocking the operation of the earth-fault relay.