Basler Electric BE1-851 - Manual (Page 17)

SECTION 1 • GENERAL INFORMATION
General
The BE1-851 Overcurrent Protection System is an economical, microprocessor based, multifunction
system. It is available in S1 (Basler/GE style), H1 (half-rack), and F1 (Westinghouse FT-11 size)
configurations. BE1-851 features include:
• Time & Instantaneous Overcurrent Protection
• Control
• Automatic Reclosing
• Breaker Failure Protection
• Breaker Monitoring
• Metering Functions
• Communication
BE1-851 relays have four programmable contact sensing inputs, five programmable outputs, and one
alarm output. Outputs can be assigned to perform protection, control, or indicator operations through
logical programming. For example, protection functions could be programmed to cause a protective trip.
Control functions could be programmed to cause a manual trip, manual close, or automatic reclose.
Indicators could be configured to annunciate relay failure, a settings group change, and others.
Protection scheme designers may select from a number of pre-programmed logic schemes that perform
the most common protection and control requirements. Alternately, a custom scheme can be created
using BESTlogic™.
A simplified “How To Get Started” procedure for BE1-851 users is provided in Section 2, Quick Start.
Features
The BE1-851 relay includes many features for the protection, monitoring, and control of power system
equipment. These features include protection and control functions, metering functions, and reporting and
alarm functions. A highly flexible programmable logic system called BESTlogic allows the user to apply
the available functions with complete flexibility and customize the system to meet the requirements of the
protected power system. Programmable I/O, extensive communication features, and an advanced
human-machine interface (HMI) provide easy access to the features provided.
The following information summarizes the capabilities of this multifunction device. Each feature along with
how to set it up and how to use its outputs is described in complete detail in the later section of this
manual.
Input and Output Functions
Input functions consist of power system measurement and contact sensing inputs. Programmable contact
outputs make up the output functions. Input and output functions are described in the following
paragraphs.
Power System Measurement Functions
BE1-851 relays are designed for operation on both 50 and 60 Hz systems and have four current inputs to
measure phase and neutral currents. It is a numerical device that samples the analog current waveforms
and uses mathematical algorithms to measure the operating quantities. One of three current
measurement algorithms may be individually selected for phase and neutral. Those are:
• Fundamental
• Average
• Wideband RMS
The fundamental algorithm responds to the fundamental component of the current and rejects the
harmonic components. The average algorithm emulates an RC measurement circuit and has a relatively
flat response characteristic over a wide frequency range. The wideband RMS algorithm measures all
components of the current up to the seventh harmonic.
In addition, the relay measures the magnitude of the negative-sequence component of the fundamental
phase current quantities. The negative-sequence measurement has by definition a fundamental response
characteristic.
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