The SIPROTEC 7SD82/86/87 line differential protection have been designed particularly for the selective protection of overhead lines and cables with single-ended and multi-ended infeed in medium-voltage and high-voltage systems. Transformers and compensating coils in the protection range are also possible. With their flexibility and the high-performance DIGSI 5 engineering tool, the SIPROTEC 5 devices offer future-oriented system solutions with high investment security and low operating costs.