Product scope
SIPROTEC 7SJ85 is Siemens’ modular overcurrent protection device for feeders, lines and capacitor banks, with control, monitoring and automation functions.
Engineering significance
The SIPROTEC 5 platform supports extensive functional integration. This can reduce separate devices but increases the importance of controlled configuration, logic review, firmware management and test coverage.
Application checks
Define system grounding, directional polarisation, autoreclose, breaker failure, arc protection, synchrocheck, communications and control authority before selecting hardware. Check CT/VT input type, binary I/O count and communication modules against the complete scheme.
Specification caution
Use the current 7SJ82/7SJ85 manual and exact order configuration. Platform capability is not identical to the capability of every delivered device.
Official sources and revision control
Technical review date: 16 August 2026. Standards and product capabilities can change; confirm the project-specific edition, firmware, options and ordered configuration before engineering or procurement.