ABB REX 521 Technical Reference Manual, Standard Configurations

166
1MRS751802-MUM
Protection Relay
Technical Reference Manual, Standard Configurations
REX 521
9.4.2. Measurement connections
The three-phase current and neutral current transformers are connected to the
connector X1.1 on the rear panel. The rated currents of the measuring input are 1 A
and 5 A.
Fig. 9.4.2.-1 Connection diagram for the standard configuration B02 with three
CTs in a residual connection
The technical data of the current transformers are set via the Relay Setting Tool or
the local HMI. The settings can be found in
Main menu\Configuration\Meas. devices\. Refer to
REX 521
Technical Reference Manual, General
(see Section 1.5. Related documents) for
further information about how to set the rated currents.
9.4.3. Protection
All the necessary settings for the protection functions can be set via the Relay
Setting Tool or the local HMI. The settings can be found in
Main menu\Protection\.
The following protection functions can be implemented in the same way as in the
first application example (see Section 9.1. Outgoing feeder, Basic B01):
• Overcurrent protection
• Earth fault protection
• Phase discontinuity protection
• Thermal overload protection
REX 521
CTres

ABB REX 521 Specifications

General

Brand	ABB
Model	REX 521
Category	Other
Language	English