White Papers

Working with the Trip Characteristic Curves of ABB SACE Low Voltage Circuit-Breakers.
It is the first publication of the new collection of technical documents called White Papers; a series of documents which can give practical information and explain in a direct and exhaustive way the characteristics of our products and of their specific applications. Scope of this document is making easier the reading and the interpretation of the characteristic curves (trip curves, specific let-through energy curves and limitation curves) of the Molded-Case Circuit-Breakers (MCCBs) and Low Voltage Power Circuit-Breakers (LVPCBs) manufactured by ABB SACE in compliance with the American Standards UL 489 and UL 1066.


White Paper - Vol. 2

Directional protection and directional zone selectivity
It is the second publication of the new collection of technical documents called White Papers; a series of documents which can give practical information and explain in a direct and exhaustive way the characteristics of our products and of their specific applications.
The “Directional protection and directional zone selectivity” White Paper describes the sense, the potentials, the application area and the use of “D” directional protection and “SdZ” directional zone selectivity functions.
Furthermore different application references and examples of plants where the use of this kind of protections has permitted to gain remarkable results are described.


White Paper - Vol. 3

Integration between the MV protection and control unit REF542 and the LV protection trip unit PR123: selectivity and earth fault
The third volume of White paper series is intended to illustrate the possibilities of integration between ABB medium and low voltage protection trip units, paying particular attention to the protection and control unit type REF542 (for MV) and the protection trip unit PR123 (for LV).
The text, starting from brief theoretical analysis, decribes, by means of suitable examples, some useful strategies for an appropriate coordination and the correct cabling logic that must be implemented on ABB units.
Moreover, in the fourth paragraph, a real "how to make" section is given: here are listed all the components you need to use in order to realize the strategies previously shown, from the signalling unit to the external toroids.


White Paper - Vol. 4

Double Ground Fault Protection - Implementation

The fourth volume of the series "White Paper" is intended to offer the necessary guidelines for the correct implementation of the “Double G” in the Emax circuit-breakers equipped with PR123/LSIG and PR333/P LSIG trip units.
Thanks to a chrono-amperometric discrimination and to the MV/LV integration, this advanced protection permits to ensure protection against earth faults on the load side of the low voltage air circuit-breaker and to ensure protection against earth faults in the section between the secondary of the transformer and the upstream terminals of the air circuit-breaker.
The documentation is divided into:

• Generalities: a brief introduction to the application field.
• Application Description: the operating principle of the Double G protection.
• References: an example of the application.
• Practical Guide: how to put into practice the Double G protection.
• Bibliography.