Busbar protection

Busbar protection – SIPROTEC 7SS52

SIPROTEC 7SS52  (phase-out product)

The SIPROTEC 7SS52 numerical protection is a selective, reliable and fast protection for busbar faults and breaker failure in medium, high and extra-high voltage substations with various possible busbar configurations.

Industry Mall

Select and buy

Features & functions

Busbar protection SIPROTEC 7SS52 (phase-out product)


The protection is suitable for all switchgear types with iron-core or linearized current transformers. The short tripping time is especially advantageous for applications with high fault levels or where fast fault clearance is required for power system stability. 

The modular hardware allows the protection to be optimally matched to the busbar configuration. The decentralized arrangement allows the cabling costs in the substation to be drastically reduced. The SIPROTEC 7SS52 busbar protection caters for single, double or triple busbar systems with or without and quadruple busbar systems without transfer bus with up to: 48 bays, 16 bus couplers, and 24 sectionalizing disconnectors and 12 busbar sections.


Communication interfaces

  • FO interface 
    – IEC 60870-5-103

  • Electrical interface 
    – IEC 61850


Busbar protection functions

  • Busbar differential protection

  • Selective zone tripping

  • Very short tripping time (<15 ms)

  • Extreme stability against external fault, short saturation-free time (≥2 ms)

  • Phase-segregated measuring systems

  • Integrated check zone

  • 48 bays can be configured

  • 12 busbar sections can be protected

  • Bay-selective intertripping

Breaker failure protection functions

  • Breaker failure protection (single-phase with/without current)

  • 5 operation modes, selectable per bay

  • Separate parameterization possible for busbar and line faults

  • Independently settable delay times for all operation modes

  • 2-stage operation bay trip repeat/trip busbar

  • Intertrip facility (via teleprotection interface)

  • “Low-current” mode using the circuitbreaker auxiliary contacts

Additional protection functions

  • End-fault protection with intertrip or bus zone trip

  • Backup overcurrent protection per bay unit (definite-time or inverse-time)

  • Independent breaker failure protection per bay unit


  • Distributed or centralized installation

  • Easy expansion capability

  • Integrated commissioning aids

  • Centralized user-friendly configuration/parameterization with DIGSI

  • Universal hardware


Downloads and services

Retrofit and enhancement services

Retrofit and enhancement services

Extend the lifespans of your energy system and thereby significantly reduce your costs of ownership with our retrofits and enhancement services for energy automation.

Power Academy training services

Power Academy training services

Our goal is to prepare you for new professional challenges in power transmission and distribution. We offer professional training courses with different training methods like Virtual Classroom Training, Classroom Training, WBTs, Webinars and Blended Learning. You can choose between open enrollment training courses, customized training courses, workshops or long-term trainings (curricula).

Energy Automation and Digital Grid Newsletter


Receive news about the Digital Grid and Energy Automation portfolio and offerings!

Energy Automation Webinars

Energy automation webinars

Learn more in one of our energy automation webinars for protection and substation automation engineers and experts.