The MiCOM P521 relay provides high-speed, two-ended current differential unit protection of overhead lines and underground cables in applications such as ring mains and parallel feeders.

The MiCOM P521 relay provides fast, efficient current differential protection. It is very flexible and can be applied to a wide range of power systems. Offering a variety of communications interface options, MiCOM P521 provides valuable local and remote back-up protection.

Multiple interface options and tripping for wide range of power systems

Ensuring optimum phase selection, MiCOM P521’s many integrated protection functions allow for application to a wide range of power systems. It offers both local and remote back-up protection. MiCOM P521 also provides fast tripping results for an internal fault, and stability for any out-of-zone fault.

Its many interface options support metallic, direct fiber optic and multiplexed digital links. Tripping uses a proven characteristic comparing differential current with through current, enabling easier testing. MiCOM P521 includes a full range of integrated back-up protection, thereby enhancing reliability.

Highly selective unit protection and value added back-up protection

MiCOM P521 offers highly selective unit protection and a variety of end-to-end communications interface options. Its numerous integrated back-up elements can run as hot standby in the event of a communications channel outage.