Breaker Failure Protection
MiCOM P821 is an Advanced Breaker Failure and protection relay based on the latest numerical technology.
MiCOM P821 provides enhanced protection due to the advanced numerical technology used in its design. It is highly reliable and flexible, and can be used with any application.
Wide monitoring capacities for maximum control
MiCOM P821 offers a range of protection functions, combined with extensive monitoring capacities, for optimum efficiency and maximum control of electrical schemes. An enhanced breaker failure protection function provides back up protection when the primary circuit fails to isolate the fault.
While this numerical relay is designed as a phase segregated detection device for EHV/HV/MV levels, it is also flexible enough for all voltage ranges and can be applied to any application.
The MiCOM P821 can use either single-stage breaker failure protection (tBF1) for back up protection to the local circuit breaker, or two-stage breaker failure protection (tBF1 & tBF2).
Reliable detection, easy to program
MiCOM P821 ensures reliable phase segregated detection for 1/3 pole breaker tripping, and is suitable for all voltage levels. It also provides sensitive residual current detection and boast a fast RESET time. Equipped with one or two-stage CB failure, it is easy to program with the standard MiCOM Px20 setting procedure.
Standard Manufacturers Warranty: 2 years
EcoStruxure™ for Your BusinessEcoStruxure lets you thrive in today's digital world. Make better business decisions with scalable and converged IT/OT solutions. Learn more
Reach UsHave a question, complaint or is there some feedback you’d like to send us to make your experience with Schneider Electric better? Contact an Expert
FAQEasily find and share the answer you are looking for from our online FAQ service. Browse FAQ
Distributor LocatorA simple tool to locate easily your nearest Schneider Electric distributor. Find a Distributor
MySchneider AppDiscover our new mySchneider app which offers tailored services, 24/7 self-service, and easy access to expert support and information. Download and register now to get access to recommended services and more. Get the App
Need information?Browse our resource section and find the most useful tools and documents for all our products. Browse