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Settings Example

A BE3-47N/27 relay with a nominal input rating of 120 Vac

has the following settings:

• UNBAL – 10%

• DELAY – 5 s

The relay detects a phase unbalance when any one phase

decreases to 108 Vac or increases to 132 Vac. The output

relay trips five seconds after the phase unbalance is

detected. The output relay also trips if all phases decrease

to 85% of nominal, or 102 Vac.

INSTALLATION

BE3 phase balance relays are designed for mounting on

standard DIN rails that comply to DIN-EN 50022. Mounting

involves hooking the top edge of the cutout on the base of

the case over one edge of the DIN rail. The opposite side of

the cutout containing the release clip is then pushed over

the opposite side of the DIN rail. To remove or reposition the

relay, lever the release clip and move the relay as required.

BE3 relays should be installed in a dry, vibration-free

location where the ambient temperature does not exceed

the operating temperature range. Connections to the relay

should be made using wire that meets applicable codes and

is properly sized for the application. Figure 1 shows the

terminal connections for the BE3-47N/27 relay. Connections

for the BE3-47N relay are identical.

The BE1-CDS240 can be ordered with 12 programmable contact sensing inputs, 10 programmable outputs,

and one alarm output or eight programmable contact-sensing inputs, 14 programmable outputs and one

alarm output. Outputs can be assigned various functions by logical programming to perform protection,

control, or indicate operations. For example, protection functions can cause a protective trip operation.

Control functions can cause a manual trip, manual close, or automatic reclose operation. Indicators could

be relay alarm, setting group one enable, setting group two enable and others.

Protection scheme designers may select from an embedded pre-programmed logic scheme or from a

number of logic library schemes found in BESTCOMS™ to perform the most common protection and control

requirements or create a custom scheme using BESTlogic.

INTRODUCTION

BE3-47N phase balance relays protect three-phase lines,

transformers, motors, and generators against phase

unbalance, phase loss, and phase reversal. BE3-47N/27

relays have the added feature of undervoltage protection.

The output relay energizes and the red RELAY LED lights

when a balanced input with the proper phase sequence is

sensed. The output relay de-energizes and the RELAY LED

goes out when a fault condition is detected. The green

POWER LED indicates the condition of the power supply.

Two external controls are provided: UNBAL (unbalance) and

DELAY. The UNBAL control adjusts the percentage of

unbalanced voltage at which the relay trips. The DELAY

control provides an adjustable time delay to prevent tripping

on voltage transients.

INSTALLATION

BE3 ac voltage relays are designed for mounting on standard DIN

rails that comply to DIN-EN 50022. Mounting involves hooking the

top edge of the cutout on the base of the case over one edge of the

DIN rail. The opposite side of the cutout containing the release clip

is then pushed over the opposite side of the DIN rail. To remove or

reposition the relay, lever the release clip and move the relay as

required. BE3 relays should be installed in a dry, vibration-free

location where the ambient temperature does not exceed the

operating temperature range. Connections to the relay should be

made using wire that meets applicable codes and is properly sized

for the application. Figure 1 shows the terminal connections for the

BE3-27T, BE3-59T, and BE3-27T/59T relays.

OPERATION

BE3-27T and BE3-59T ac voltage relays have two external, user

adjustable controls marked SET and DELAY. The BE3-27T/59T has

four controls: UNDER SET, OVER SET, UNDER DELAY, and

OVER DELAY. The SET control adjusts the relay trip point. An

overvoltage trip causes the relay output to energize when the

voltage rises above the SET threshold. The overvoltage SET level

is adjustable from 100 to 125% (±3%) of nominal input (Vnom

). An

undervoltage trip causes the relay output to de-energize when the

voltage decreases below the SET threshold. The undervoltage SET

level is adjustable from 75 to 100% (±3%) of nominal input. Time

delay is the amount of time that elapses after the trip point is

reached and when the output relay operates.

Setting Example: a BE3-59T relay with a nominal input rating of 240

Vac has the following settings:

• SET – 120%

• DELAY – 4 seconds

A trip occurs when the sensing voltage rises above 288 Vac and 4

seconds elapses. Reset occurs when the voltage decreases below

285.6 Vac (1% of nominal below setpoint).

INTRODUCTION

BE3 ac voltage relays provide voltage monitoring and protection in

both single-phase and three-phase systems. They are used in

applications such as utility mains failure, regulation of power

supplies, and to protect voltage sensitive equipment. Undervoltage,

overvoltage, and combined over/undervoltage units are available.

BE3 ac voltage relays operate when the adjustable trip point is

reached. An external time delay control is provided with an

adjustment of 0 to 10 seconds (relay operating time is typically 200

milliseconds). This time delay may be used to prevent false tripping

when there are slight variations in the voltage supply. 

On overvoltage units, the output relay energizes when the input

signal exceeds the trip point. On undervoltage units, the output

relay de energizes when the input signal goes below the trip point.

A red LED indicates the state of the relay. A green LED indicates

the condition of the power supply.

The BE1-CDS240 Current Differential System is an economical, microprocessor based, multifunction

system that provides a four input, three-phase percentage differential with harmonic restraint protection.

Also included is three-phase with voltage control, ground, and negative-sequence overcurrent protection,

voltage and frequency protection, breaker failure for up to four breakers, breaker monitoring for four

breakers, transformer monitoring, and metering functions, all in an integrated system with several

communications options. The BE1-CDS240 Current Differential System is intended for use in any low

impedance current differential protection application including transformer, generator, motor, and bus

protection. Four setting groups are provided for adaptive relaying with automatic selection logic for cold

load pickup and/or dynamic setting group changes.

The BE1-CDS240 is available in a fully draw-out MX case with configurations for horizontal 19″ rack

mounting, horizontal panel mounting and vertical panel mounting. BE1-CDS240 features include:

• Up to four restraint inputs (four three-phase current circuits) and two virtual current circuits that

can be used with any combination of two current inputs

• Independent ground input

• Three voltage inputs (Va, Vb, Vc, to Vn)

• Three-phase percentage differential protection with harmonic restraint

• Three-phase voltage, frequency and overcurrent protection

• Four setting groups

• One embedded preprogrammed logic scheme

• Fourteen or 10 programmable outputs

• Eight or 12 contact sensing inputs

• Breaker failure protection for four breakers

• Front panel HMI (human-machine interface)

• Communications ports: one front RS-232, one rear RS-232, one rear RS-485 and one rear

IRIG port

• Communications protocols available: DNP3, Modbus® RTU, and ASCII

• Sequence of events recording

• Fault recording

• Oscillography

• Demand reporting

• Differential current monitoring

• Optional load profile reporting

INSTALLATION

BE3 temperature relays are designed for mounting on

standard DIN rails that comply with DIN-EN 50022.

Mounting involves hooking the top edge of the cutout on the

base of the case over one edge of the DIN rail. The opposite

side of the cutout containing the release clip is then pushed

over the opposite side of the DIN rail. To remove or

reposition the relay, lever the release clip and move the

relay as required. BE3 relays should be installed in a dry,

vibration-free location where the ambient temperature does

not exceed the operating temperature range. Connections to

the relay should be made using wire that meets applicable

codes and is properly sized for the application. Figure 2

illustrates the terminal connections for the BE3-49R

temperature relay.

A burden resistor must be installed across all unused RTD

inputs that are not connected to an actual RTD. For units

with style number 5HXXX, it is suggested that a 10 Ω

resistor be connected across any unused RTD inputs. For

units with style number 5IXXX, it is suggested that a 100 Ω

resistor be connected across any unused RTD inputs. The

minimum power rating for the burden resistors is ¼ W.

INTRODUCTION

Three-input BE3 temperature relays use resistance

temperature detectors (RTDs) to monitor remote

temperatures. When any of three monitored temperatures

exceeds a preset limit, the corresponding relay output

operates. A dc metering output indicates the highest

temperature of the three RTDs. BE3 temperature relays are

available for use with 10 Ω copper or 100 Ω platinum RTDs.

OPERATION

Three temperatures are monitored through RTDs connected

at the nine-position front panel connector. RTD connections

are labeled A, B, and C. Three user-adjustable controls are

located on the front panel: SET 1. SET 2. and SET 3. Each

setpoint is adjustable from 50 to 100% (±3%) of the RTD

temperature range. When a setpoint is exceeded, the

corresponding TRIP LED lights and the relay output

energizes. Each RTD has a corresponding LED to identify

which RTD has exceeded the temperature setpoint. For

example, if the temperature of RTDs B and C exceeds the

trip level, the B and C TRIP LEDs light and the relay output

energizes. A green LED labeled AUX indicates the power

supply status. Figure 1 illustrates the BE3-49R controls,

indicators, and terminals.