BE1-51, BE1-51_27C, BE1-51_27R, Time Overcurrent Relay

A microprocessor-based relay that provides versatile overload and fault protection on 50Hz or 60Hz systems. Adaptable for a wide range of applications; voltage control and voltage restraint models are available.

Benefits
Manuals
Bulletins
Technical Resources
Applications
Case Studies

Benefits

Flexible pickup is continually adjustable over a wide range.
Easily match system configuration with single-phase, two-phase-with-neutral, three-phase, and three-phase-with-neutral input configurations.
Timings can be tailored to the application with 16 field selectable curves.
Minimized CT costs as a result of low sensing burden.
Reduced battery load with low burden power supply.
Accurate, repeatable, and reliable operation.
Simple HMI provides clear and intuitive settings for easy configuration without the use of a computer.
LED targets provide clear annunciation of status.
Easily perform in-case system and device tests using test paddles.

Manuals

Instruction Manual
- BE1-51 Instruction Manual, Rev L, English (5MB)
  Time Overcurrent Relay
- BE1-51/27C Instruction Manual, Rev J, English (5MB)
  Time Overcurrent Relay with Voltage Control
- BE1-51/27R Instruction Manual, Rev K, English (5.2MB)
  Time Overcurrent Relay with Voltage Restraint

Bulletins

Product Bulletin
- BE1-51, 51/27C, 51/27R Bulletin, Rev 25, English (1MB)
- Standards, Dimensions and Accessories, Rev 23, English (1.4MB)
  BE1 Protection Systems and Relays
Brochure
- Brochure: Power Systems Solutions - Proven Worldwide, English (5.9MB)
  Solutions for Excitation Systems, Protection Systems/Relays, Voltage Regulators, and Genset/Engine Controllers.
- Brochure: Power Systems Solutions - Proven Worldwide, Japanese (6.4MB)
  Solutions for Excitation Systems, Protection Systems/Relays, Voltage Regulators, and Genset/Engine Controllers.

Technical Resources

Application Guide
- Application Guide: Generator Protection (2.5MB)
  Simplify the process of selecting relays and relay systems to protect generators.
- Application Guide: Motor Protection (1.3MB)
  Overview of motor hazards and detection and protection options, plus typical setting-value range for BE1-11m.
- Application Guide: Transformer Protection (2.2MB)
  Simplify the process of selecting relays and relay systems to protect power transformers.
Technical Paper
- Technical Paper: A Review of System-Grounding Methods and Zero-Sequence Current Sources (1.1MB)
  Grounding methods, sources of ground current, ground-current flow in the power system, and how each impacts protective relaying.
- Technical Paper: A Survey of Cold Load Pickup Practices (1MB)
  Cold load pickup, the causes and effects.
- Technical Paper: Application of Islanding Protection for Industrial- and Commercial-Generators (990.9KB)
  Issues associated with the islanding of an industrial- or commercial-facility power system where a synchronous generator operates in parallel with the utility source.
- Technical Paper: Arc Flash Mitigation Through Use of Voltage Controlled/Voltage Restrained Overcurrent Elements (244.2KB)
  The use of voltage controlled/voltage restrained overcurrent elements as an arc flash mitigation technique.
- Technical Paper: Bus-Protective Relaying, Methods and Application (1.9MB)
  Application of bus-protective relaying, describing and comparing differences.
- Technical Paper: Choosing the Correct Transfer Switch (569.1KB)
  For effective ground-fault protection, transfer switch must be chosen at project beginning.
- Technical Paper: Current Transformer Errors and Transformer Inrush as Measured by Magnetic, Optical and other Unconventional CTs (1.4MB)
  Errors in secondary current for these primary current conditions determine when CTs are at risk, and show, using numerical analysis, the output of a saturated CT.
- Technical Paper: Effects of Distributed Generation on Utility Protection Schemes (782.1KB)
  Addition of distributed generation to a distribution feeder can be minimized by having digital multifunction overcurrent with voltage-protection schemes.
- Technical Paper: Intertie Requirements for DGs Connected to Radial-Distribution Feeders (537.3KB)
  Proposed protection requirements for distributed generation connected to radial-distribution feeders.
- Technical Paper: Life Lessons from the Power System (1.1MB)
  Explores the basic principles of relay protection design and relay protection commissioning, while reflecting upon lessons learned.
- Technical Paper: Myths of Protecting the Distributed Resource To Electric Power System Interconnection (1.1MB)
  For the ideology of power-system protection, the myths described in this paper are better described as conditional truths rather than half-truths.
- Technical Paper: Protective Relaying Issues in Low-Voltage Systems as Addressed in the National Electric Code (1.6MB)
  Low Voltage (LV) design practices, as mentioned in the National Electric Code (NEC).
- Technical Paper: Protective Relaying When Distributed Generation is Added to Your Circuit (874.4KB)
  Advantages of having numeric multifunction protection in place when distributed generation is added to a radial-distribution circuit.
- Technical Paper: Upgrading Intertie Protection to meet TX PU Standards (1MB)
  Utilizing multifunction relays as the sole means of protection, not only for the plant and its generation, but also for the utility.

Applications

Application Guide
- Application Guide: Generator Protection (2.5MB)
  Simplify the process of selecting relays and relay systems to protect generators.
- Application Guide: Motor Protection (1.3MB)
  Overview of motor hazards and detection and protection options, plus typical setting-value range for BE1-11m.
- Application Guide: Transformer Protection (2.2MB)
  Simplify the process of selecting relays and relay systems to protect power transformers.
Application Note
- Application Note: PC-CASES (1.1MB)
  Basler Electric cases and dimensions vs. older electromechanical relays.