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INTRODUCTION

BE3-25 sync-check relays are used to ensure that two ac

circuits are synchronized. In order to be synchronized, the

frequency, phase angle, and voltage of the two circuits must

be within preset limits. When this occurs, the BE3-25 output

relay energizes. The primary application of the BE3-25 is to

enable additional generators to be brought on-line without

machine damage or system disturbance. The BE3-25 can

also be used to supervise reclosing or in any instance where

the danger of paralleling two circuits out of synchronism

exists.

APPLICATION:

The BE3-25 series are synchronizing check relays, also known

as paralleling relays. They are used to ensure that two AC

supplies are synchronized. For a system to be synchronized,

the frequency, phase angle, and voltage must be within preset

limits. The BE3-25-****4 can monitor either utility mains bus

bar and incoming generator, or two generators. 

The BE3-25-****4 offers user adjustment of the reset voltage

from 10 to 30%. This voltage corresponds to 6 to 20 electrical

degrees. The unit compares the input voltage and phase

relationship of the bus bar to that of the generator.

When the signal is within the preset limits, the relay energizes.

The BE3-25-****5 operates as the BE3 25-****4.

but has the additional feature of a dead bus facility.

This enables the relay to energize with a generator supply

only, which is a common requirement when utility mains failure

occurs.

Benefits

• Simplify protection by covering a wide range of applications using

BE3 relays.

• Accurate, repeatable, and reliable operation.

• Most models are available for shipment from stock.

• Easy, time-saving installation with BE3 DIN-rail devices.

• Provide economical industrial protection for motor, generator,

transformer, distribution, process control, and automatic transfer

applications.

• Many BE3 relay models are self-powered, eliminating the need for

additional power sources.

BE3 Series Industrial Relays provide a wide range of cost-saving options to simplify industrial

application protection related to Auto Transfer, Distribution, Generators, Motors, Process

Control, and Transformers. Multiple DIN-rail mounting options are available.

Features

• 25 Sync-Check

• 27 Undervoltage

• 27T Undervoltage with Time Delay

• 27/59 Undervoltage/Overvoltage

• 27T/59T Undervoltage/Overvoltage with Time Delay

• 32 Reverse Power

• 37 Undercurrent

• 37/51 Undercurrent/Overcurrent

• 47 Phase Sequence

• 47N Phase Balance

• 47N/27 Phase Balance with Undervoltage

• 49R (3 or 6 RTDs) Temperature Relay

• 49TH Thermocouple Overtemperature

• 49TL Thermocouple Undertemperature

• 51 Overcurrent

• 59 Overvoltage

• 59T Overvoltage with Time Delay

• 74SL, SH, SD Millivolt Undervoltage, Overvoltage, Under/Overvoltage

• 74TL, TH, TD Milliamp Undercurrent, Overcurrent, Under/Overcurrent

• 74VL, VH, VD DC Undervoltage, Overvoltage, Under/Overvoltage

• 76SH DC Overcurrent with Inverse Time Delay

• 81O Overfrequency

• 81U Underfrequency

• 81O/U Overfrequency/Underfrequency

• 81OT Overfrequency with Time Delay

• 81UT Underfrequency with Time Delay

• 81OT/UT Overfrequency/Underfrequency with Time Delay

Benefits

• Limit generator damage with 100% stator ground-fault protection.

• Wide range of applications covered with four overvoltage and four

undervoltage setting ranges.

• Meet protection timing requirements with instantaneous-, definite-, and

inverse-time characteristics options.

• Accurate detection of fundamental and third harmonic content using 40

dB harmonic filtering.

• Minimized potential transformer (PT) costs as a result of low sensing

burden.

• Reduced battery load with low burden power supply.

• Accurate, repeatable, and reliable operation.

• Simple human-machine interface (HMI) provides clear and intuitive

settings for easy configuration.

• LED targets provide clear annunciation of status.

• Easily perform in-case system and device tests using test plugs.

Overview

The BE1-59N provides accurate 100% stator-ground protection for ungrounded

and high-resistance grounded generators.

Features

• Provides 100% stator ground fault protection.

• 100/120 Vac or 200/240 Vac nominal sensing input.

• Four sensitivity ranges for overvoltage: 1 to 20 and 10 to 50 Vac for a

100/120 Vac input and 2 to 40 and 20 to 100 Vac for a 200/240 Vac

input.

• Four sensitivity ranges for undervoltage: 0.1 to 2.5 Vac and 0.5 to 12

Vac for a 100/120 Vac input and 0.2 to 5 Vac and 1 to 24 Vac for a

200/240 Vac input.

• Instantaneous, definite, and inverse time characteristics.

• 40 dB harmonic filtering.

• Low sensing input burden.

• Power supply status contact.