Measurement Connections; Protection - ABB REX 521 Technical Reference Manual, Standard Configurations

1MRS 751802-MUM
10.1.2.
10.1.3.
Protection Relay
Technical Reference Manual, Standard Configurations

Measurement connections

The three-phase current, neutral current transformers and residual voltage
transformer are connected to the connector X1.1 on the rear panel. The rated currents
of the measuring input are 1 A and 5 A and additionally, for earth-fault, 0.2 A. The
rated values for voltage are 100 V, 110 V, 115 V and 120 V.
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The technical data of the current transformers and the voltage transformer are set via
the Relay Setting Tool or the local HMI. The settings can be found in
Main menu\Configuration\Meas. devices\. Please refer to Technical
Reference Manual, General (1MRS 751108-MUM) for further information about
how to set the rated currents and voltage.

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 (chapter 9.1.).
• overcurrent protection
• phase discontinuity protection
• thermal overload protection
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