BE1-50/51, Self-Powered Time Overcurrent Relay

A single-phase self-powered, microprocessor-based time/instantaneous overcurrent relay that provides cost-saving overload and fault protection for generators, transformers, feeders, and motors. Available in multiple-rack, panel, and retrofit mounting options.

See the Relay Upgrade Experts Chart in the Technical Resources tab below to determine if a Basler relay can replace your older style relay.


  • Accurate, repeatable, and reliable operation.
  • No additional power source required since relays are self-powered from 50/60 Hz systems. Available in five- or one-amp CT secondary models.
  • Timings can be tailored to the application with multiple field-selectable curves.
  • Flexible pickup is continuously adjustable over a wide range.
  • Instantaneous protection can be set lower to provide more complete protection with a design that minimizes transient overreach.
  • Reduce arc flash hazards by applying a second independent instantaneous element available.
  • Models available to replicate decaying reset of electromechanical relay disks when current drops to zero.
  • Replace existing electromechanical relays with specifically-wired retrofit models.
  • Reduce CT costs with low sensing and supply burdens.
  • Reduce maintenance labor by eliminating the need for re-calibration.
  • Testing is easy with drawout construction for all models and in-case testability for most models.



Technical Resources


Case Studies