Basler Electric BE1-87T User Manual

INSTRUCTION MANUAL

FOR

TRANSFORMER DIFFERENTIAL RELAY

BE1-87T

BE1-87T

TRANSFORMER DIFFERENTIAL

Style No. D2E A1J D1S0F

R

Serial No. XXXXXXXXXXXX

PUSH TO

ENERGIZE

OUTPUT

R

U

P0052-22

Publication: 9171300990
Revision: V 03/12

INTRODUCTION

This instruction manual provides information about the operation and installation of the BE1-87T
Transformer Differential relay. To accomplish this, the following information is provided:

 General Information and Specifications
 Controls and Indicators
 Functional Description
 Installation
 Test Procedures

WARNING!

To avoid personal injury or equipment damage, only qualified personnel should
perform the procedures in this manual.

NOTE

Be sure that the BE1-87T is hard-wired to earth ground with no smaller than 12
AWG copper wire attached to the ground terminal on the rear of the unit case.
When the BE1-87T is configured in a system with other devices, it is
recommended to use a separate lead to the ground bus from each unit.

9171300990 Rev V BE1-87T Introduction i

First Printing: June 1990

Printed in USA

Copyright © 1990-2012 Basler Electric, Highland Illinois 62249 USA

All Rights Reserved

March 2012

CONFIDENTIAL INFORMATION

of Basler Electric, Highland Illinois, USA. It is loaned for confidential use,
subject to return on request, and with the mutual understanding that it will not
be used in any manner detrimental to the interest of Basler Electric.

It is not the intention of this manual to cover all details and variations in equipment, nor does this manual
provide data for every possible contingency regarding installation or operation. The availability and design
of all features and options are subject to modification without notice. Should further information be
required, contact Basler Electric.

For terms of service relating to this product and software, see the Commercial Terms of Products and
Services document available at www.basler.com/terms

.

BASLER ELECTRIC

12570 STATE ROUTE 143

HIGHLAND IL 62249-1074 USA

http://www.basler.com, [e-mail]

PHONE [phone] FAX [phone]

ii BE1-87T Introduction 9171300990 Rev V

REVISION HISTORY

The following information provides a historical summary of the changes made to the BE1-87T instruction
manual (9171300990). Revisions are listed in reverse chronological order.

Manual

Revision and Date

V, 03/12

U, 08/11

T, 03/11

S, 09/10

R, 09/07

Q, 10/05

P, 05/03

N, 09/00

Change

 Updated format of Table 1-3, Power Supply Ratings, to be consistent

with other manuals.

 Standardized case and cover drawings in Section 4.

nd

 Updated 2

harmonic restraint specs for 5 A & 1 A CTs in Section 5.

 Updated formatting to current style used.

nd

 Updated 2

& 5th harmonic restraint specs in Section 1.

 Updated “K” type power supply burden in Table 1-3.
 Updated GOST-R statement in Section 1.
 Updated rear case drawings in Section 4.
 Removed references to extender card in Sections 4 and 5.
 Updated Storage statement in Section 4.

 Replaced magnetic type targets with electronic type targets.
 Updated power supply burden data and output contact ratings.
 Updated front panel illustrations to show laser graphics.
 Moved content of Section 6, Maintenance to Section 4, Installation.
 Added GOST-R certification to Section 1, General Information.

 In Section 1, General Information, Specifications, corrected values for

Maximum Current per Input for 1 Ampere CT Units.

 In Section 5, Test Procedures, corrected values inside CAUTION box

for 1 AMP CT on page 5-14.

 Added a thumbscrew to the figure on the manual front cover.
 Added “not all styles” to the Power Supply Output heading on page 3-

4 as well as added “NOTE” and a text box around the second last
paragraph on page 3-4.

 Added the new thumbscrew to Figure 4-1 and changed the height

dimensions in Figure 4-2.

 Clarified the terminal numbers on Figure 4-6b.
 Added a shorting bar between terminals 6 & 7 in Figure 4-11.
 Added a shorting bar and normally open contact and normally closed

contact effecting terminals 1, 2, & 5 in Figure 4-12.

 Step 13 was corrected on pages 4-31 and 4-39 to include R

in the

w

formulas.

 Values were changed to Table 5-4 under Option 1-0 for Unrestrained

Trip.

 Corrected Table 1-3 to show power supply ranges.
 Changed instruction manual front cover, Figures 4-1, 4-3, and 4-5 to

show new unit case covers.

 Changed Figure 4-32 per markup.

9171300990 Rev V BE1-87T Introduction iii

Manual

Revision and Date

M, 04/99

L, 05/97

K, 03/97

J, 01/96

Change

 Table 3-1 changed mid range nominal volt 125 Vac to 120 Vac.
 Corrected Figures 4-24, 4-31a, and A-3
 Corrected page 4-38, Step 10; added note to page 4-39, Step 13, and

corrected Steps 14 and 16.

 Page A-2, changed 3-Phase fault ratio current to 3-phase fault

current.

 Page A-3, corrected formulas for Figure A-3.
 Under Section 4, Procedure One, Verify CT Performance, changed

the procedure to the ANSI accuracy class method. This forced
changes in the following steps: 12, 13, 14, 16, 18, 20, and 21.

 Under Section 4, Procedure Two, Verify CT Performance, changed

the procedure to the ANSI accuracy class method. This forced
changes in the following steps: 12, 13, 14, and 16.

 Added ECO revision information to Table 8-1.
 Added Setting Note 7 (ANSI Accuracy Class Method) to Appendix A.

 To delete the part number from the front cover of the manual.
 Deleted all references to Service Manual 9171300620.

 Changed the Title of Section 2 from “Controls and Indicators” to

“Human-Machine Interface”.

 Replaced the Power Supply Options paragraphs with a new Power

Supply paragraph explaining the new power supply design.

 Deleted Figure 3-2 and added Table 3-1, Wide Range Power Supply

Voltage Ranges.

 Changed Power Supply Status Output for Type G power supply on

the formerly page 3-6 (now page 3-4) from terminals 9 and 20 to
terminals 9 and 19.

 Added information to Section 4 to help the user understand the

procedures better.

 Deleted all NOTES FOR USERS OF SENSING INPUT TYPE F

RELAYS and added Section 7, Difference Data.

 Changed previous Section 7, Manual Change Information, to Section

8.

 Added an Appendix A to clarify the setting procedures.
 Added an index to help the user find information easier.
 Changed the format of the manual.

 Deleted “Difference Data” (formerly Section 7) and included notes for

users of Type F relays.

 Moved all information regarding relay settings and checking relay

setting from Section 5, Testing and Setting, to Section 4, Installation.
Section 5 now contains information on test procedures.

 Combined 50 and 60 Hz Verification Tests.
 Various editorial changes.
 Reformatted instruction manual as Windows Help file for electronic

documentation.

iv BE1-87T Introduction 9171300990 Rev V

Manual

Revision and Date

I, 01/95

 Added outline (box) to Figure 5-8 to highlight the figure.

Change

 Page 5-42, Step 5, changed, “should be less than 4.45” to, “must be

less than 4.45”.

 Added note to page 5-43, Step 10 and corrected the formula in Step

10.

 Page 5-45, Step 18, corrected formula and high side results; and

Step 19, changed last sentence from H (13 x tap) to S (21 x tap).

 Page 5-46, Steps 20 and 21, corrected figure references.

H, 12/94

 Page 1-6, changed Specification for Restrained Output, Pickup

Accuracy.

 Changed Section 5, Testing and Setting, Verification Tests (all

models): Steps 1, 4, 5, and 8; and Table 5-4.

 Page 5-50, Jumper Positions Wye-Delta 1, Step 3: Corrected Input 2

terminal identifications.

 Page 5-51, Jumper Positions Delta2-Delta2, Step 2: Corrected

verification statement.

G, 09/94

 Changed all sections to reflect new Option 1-1.
 Added to Section 5 four examples for testing relays to clarify test

procedures.

 Added to Section 5 one procedure for setting relays.
 Corrected typographical and illustration errors.

F, 03/93

 Changed formula pages 5-4, 5-10, 5-16, and 5-22 from I = the square

root of K over t, to I = K over the square root of t.

E, 01/93

 Manual was revised to incorporate a revision in the relay that made

sensing input type F obsolete and included the 1 A, 60 hertz and 5 A,
50 hertz model relays.

 Section 5, Test Setup, diagrams were changed to clarify relay

connections.

 Added three relay Internal Connection diagrams.
 Changed unrestrained maximum time to trip, reference old Tables 5-4

and 5-8 (new Tables 5-4, 5-8, 5-12, and 5-16).

 Renamed Section 7, Manual Change Information to Section 8,

Manual Change Information and added new Section 7, Difference

Data to support BE1-87T relays with Sensing Input Type F.

D, 06/92

 Manual was revised to include the 1 A, 50 Hz model relay and

reformatted to a new Instruction Manual style.

 Additional connection diagrams were included in Section 4 and test

plug information was added to Section 6.

 Minor typographical errors were also corrected.

C, 03/91

 Table 5-1 was expanded and Figure 5-4 Test Setup illustration was

added.

 Miscellaneous editing.

B, 03/91

 Manual (with the exception of Section 2) was rewritten for ease of

use.

A, 06/90

 Figure 3-1 (Functional Block Diagram) corrected.
 Formula in caution note (formerly on p. 4-17, now on p. 5-2)

corrected.

 Miscellaneous editing.

9171300990 Rev V BE1-87T Introduction v

vi BE1-87T Introduction 9171300990 Rev V

CONTENTS

SECTION 1 • GENERAL INFORMATION ................................................................................................ 1-1

SECTION 2 • CONTROLS AND INDICATORS ........................................................................................ 2-1

SECTION 3 • FUNCTIONAL DESCRIPTION ........................................................................................... 3-1

SECTION 4 • INSTALLATION .................................................................................................................. 4-1

SECTION 5 • TEST PROCEDURES ........................................................................................................ 5-1

SECTION 6 • DIFFERENCE DATA .......................................................................................................... 6-1

APPENDIX A • SETTING NOTES ............................................................................................................ A-1

9171300990 Rev V BE1-87T Introduction vii

viii BE1-87T Introduction 9171300990 Rev V

SECTION 1 • GENERAL INFORMATION

TABLE OF CONTENTS

SECTION 1 • GENERAL INFORMATION ................................................................................................ 1-1

Introduction ............................................................................................................................................ 1-1

Description ............................................................................................................................................. 1-1

Application.............................................................................................................................................. 1-2

Single-Phase ...................................................................................................................................... 1-2

Three-Phase ....................................................................................................................................... 1-2

Percentage Restraint .......................................................................................................................... 1-2

Second-Harmonic Restraint ............................................................................................................... 1-2

Fifth-Harmonic Restraint .................................................................................................................... 1-3

Unrestrained Trip ................................................................................................................................ 1-3

Options ................................................................................................................................................... 1-3

Push-To-Energize Output Pushbuttons ............................................................................................. 1-3

Auxiliary Output Contacts ................................................................................................................... 1-3

Power Supply ..................................................................................................................................... 1-3

Model and Style Number ....................................................................................................................... 1-4

Style Number Example ....................................................................................................................... 1-4

Specifications ......................................................................................................................................... 1-5

Figures

Figure 1-1. Style Number Identification Chart ........................................................................................... 1-4

Figure 1-2. Percentage Restraint Characteristic ....................................................................................... 1-6

Figure 1-3. Unrestrained Response Times and Restrained Response Times .......................................... 1-8

Tables

Table 1-1. Multiples of Tap ........................................................................................................................ 1-6

Table 1-2. Harmonic Attenuation
Table 1-3. Power Supply Specifications

............................................................................................................... 1-7

.................................................................................................... 1-9

9171300990 Rev V BE1-87T General Information i

ii BE1-87T General Information 9171300990 Rev V

SECTION 1 • GENERAL INFORMATION

Introduction

These instructions provide information concerning the operation and installation of BE1-87T Transformer
Differential Relays. To accomplish this, the following is provided:

• Specifications

• Functional characteristics

• Mounting information

• Setting procedures and examples

WARNING!

To avoid personal injury or equipment damage, only qualified personnel should
perform the procedures presented in these instructions.

These instructions may be used in place of all earlier editions. For change information, see Section 8.

Description

BE1-87T Transformer Differential Relays provide primary protection for power transformers and are
available in either Single-Phase or Three-Phase configurations. The solid-state BE1-87T compares the
currents entering and leaving the protected transformer. If a fault is detected, the relay initiates a trip
signal to isolate the power transformer. This limits damage to the transformer and minimizes the impact on
the power system.

BE1-87T relays use three types of restraint:

NOTE FOR USERS OF SENSING INPUT TYPE F RELAYS

Users of BE1-87T relays with Sensing Input Type F (three-phases three inputs
per phase) will find Difference Data in Section 6 of this manual that describes
features specific to these relays. The three-phase, three inputs per phase
design, previously available as Sensing Input Type F, has been modified and
is now available as Sensing Input Type G. Due to differences in components
and output terminal connections, Type G relays are not compatible with earlier
versions of the BE1-87T with Sensing Input Type F. There are also differences
in the output connections as described in Section 6, Difference Data.

• Percentage of through-current

• Second harmonic

• Fifth harmonic

Selectivity in differential relaying is based on the ability to distinguish between internal and external faults.
This is achieved by comparing the currents into and out of a power transformer. Comparing these currents
often requires more than two inputs. For example:

• Power transformers may have a significant portion (greater than 10%) of the current flowing in a

third or tertiary winding.

• Power transformers can have multiple breakers for a given winding (e.g., ring bus or breaker-and-

a-half bus).

BE1-87T relays are available with up to five restraint inputs for the single-phase unit and up to three
restraint inputs per phase for the three-phase unit.

9171300990 Rev V BE1-87T General Information 1-1

Application

In general, power transformers have different values of current flowing through their primary, secondary,
and tertiary windings. These currents have specific phase relationships depending upon the connections
of the individual windings (e.g., wye/delta). As inputs to a differential relay, these currents must be
compensated or scaled so that the relay can compare the inputs and determine when an unbalance
exists. Under ideal operating conditions, the scaled vector sum of these currents is zero.

Because it is practically impossible to match the magnitudes of these detected currents from the various
power windings using standard CT ratios, the currents are matched within the relay by scaling each of the
applied currents by an appropriate factor called a Tap Setting. This is set by means of the front panel
INPUT dials. By selecting suitable tap ratios, the applied currents are scaled within the relay to achieve
the desired balance for normal operating conditions. BE1-87T relays offer a range of available tap settings
for inputs between 0.4 A to 1.78 A (Sensing Input Range Options 2 and 4 for a 1 A CT) or 2.0 to 8.9 A
(Sensing Input Range Options 1 and 3 for a 5 A CT). These settings are independently adjustable in
increments of 0.02 A for Sensing Input Range Options 2 and 4, or 0.1 A for Sensing Input Range Options
1 and 3. These small increments allow more precise scaling of the applied currents and usually eliminate
the need for installing auxiliary ratio-matching CTs.

Single-Phase

BE1-87T Single-Phase relays require phase angle compensation to be accomplished externally by proper
connection of the system CT secondaries. A wye/delta transformer requires that the CT secondaries be
connected in delta for the wye winding and in wye for the delta winding. This type of connection also
eliminates the zero-sequence component of current which could cause a false trip (operation) during
external ground fault conditions on the wye system.

Three-Phase

BE1-87T Three-Phase relays can provide zero-sequence filtering and compensation for phase shifts
introduced by the connections of the power transformer. This 30° Phase Shift compensation (either ±30°
or no compensation) is field selectable. Additionally, this feature allows sharing the transformer differential
relay CTs with other relays or instrumentation.

BE1-87T relays use the highest input current (in per unit values) to operate on maximum restraint. The
relay does not have a conventional operate winding in the internal magnetics. Operating current is
developed within the electronics of the relay.

Percentage Restraint

A primary concern in differential relay applications is security against high current levels caused by faults
outside the protected zone. Inevitable differences in the saturation characteristics between current
transformers require a compensating decrease in relay sensitivity. It is also necessary to be able to adjust
the sensitivity to compensate for transformer voltage taps or CT mismatches. This is accomplished by
providing a restraint factor proportional to the current flowing through the protected zone (through­current).

BE1-87T relays maintain sensitivity at a specified ratio of trip current to through current. This ratio,
generally referred to as slope, is front-panel adjustable in 5% increments from 15 to 60%.

Second-Harmonic Restraint

Magnetizing inrush current presents another problem unique to transformer differential relays. Relays
must be capable of detecting the small differences in current caused by the shor ting of a limited number
of turns, yet remain secure against the occurrence of magnetizing currents many times the transformer
rating (as seen at one set of terminals).

Although magnetizing inrush is usually associated with the energizing of the transformer, any abrupt
change in the energizing voltage may produce this phenomenon. Common causes are the transients
generated during the onset, evolution, and removal of external faults. Desensitizing the relay only during
energization is therefore insufficient.

Magnetizing inrush produces an offset sine wave rich in all harmonics. BE1-87T relays use the second
harmonic to restrain operation because it predominates and because it does not occur in significant
magnitude or duration at other times.

1-2 BE1-87T General Information 9171300990 Rev V

Three-phase BE1-87T relays use second-harmonic sharing. The second-harmonic content of all three
phases is summed together to derive the restraint for each phase. As a result, the second-harmonic
inhibit range and the associated factory setting, is higher than on single-phase relays.

Fifth-Harmonic Restraint

Power transformer overexcitation causes additional exciting current to flow into one set of terminals. This
presents an apparent differential (or operating) current not attributable to an internal fault. Although
potentially damaging, overexcitation is not an internal fault and, therefore, is not an appropriate condition
for transformer differential relay operation. One of the principal components in the complex waveform
produced during overexcitation is the fifth harmonic. BE1-87T relays use fifth-harmonic restraint to inhibit
the differential relay operation.

Unrestrained Trip

Severe internal transformer faults may cause CT saturation. Under such circumstances, harmonic­restraint transformer differential relays may fail to trip because of the extremely high harmonic content in
the waveform. Lack of operation can result in severe transformer damage.

BE1-87T relays provide an independent unrestrained tripping function. When set above the possible
inrush current magnitude, this function provides high-speed protection for the most severe internal faults.

Options

Push-To-Energize Output Pushbuttons

Two PUSH-TO-ENERGIZE OUTPUT switches are available as a means to verify external output wiring
without the inconvenience of having to test the entire relay. Option 2-S provides a small pushbutton switch
for each isolated output function (Restrained and Unrestrained) and may be actuated by inserting a thin,
non-conducting rod through access holes in the front panel. Refer to Figures 2-1 through 2-4 for location.

Appropriate power must be applied to Power Supply terminals 3 and 4 (shown in Figures 4-7 through 4-

10) for these pushbuttons to operate the output relays. However, it is not necessary to apply currents to
the sensing inputs of the relay for these switches to function.

Auxiliary Output Contacts

Three types of auxiliary output contacts are available: Normally open, normally closed and SPDT. The
contacts can be made to respond to a restrained trip, an unrestrained trip, or both. Refer to the Functional
Description: Auxiliary Relay Option for further information.

Power Supply

Various power supply options are available to allow the BE1-87T to be used with standard supply
voltages. See the Style Number Identification Chart, Figure 1-1, for details.

9171300990 Rev V BE1-87T General Information 1-3

Model and Style Number

The electrical characteristics and operational features of the BE1-87T Transformer Differential Relay are
defined by a combination of letters and numbers that make up its Style Number. The Model Number
together with the Style Number, describe the options included in a specific device and appear on the front
panel, drawout cradle and inside the case assembly.

Upon receipt of a relay, be sure to check the Style Number against the requisition and the packing list to
ensure that they agree.

Style Number Example

The Style Number Identification Chart (Figure 1-1) defines the electrical characteristics and operational
features included in BE1-87T relays. For example, if the Style Number were G1E-A1Y-D1S0F, the device
would have the following:

BE1-87T

G

1

E

A1

Y

D

1

S

0

F

Model Number (designates the relay as a Basler Electric, Class 100, Transformer Differential
Relay)

Three-phase sensing with three inputs per phase

2.0 to 8.9 A Sensing Range at 60 Hz

One unrestrained output contact and one restrained output contact

No intentional delay in the outputs

48/125 Vdc switchable

Current operated targets

Percent I

Push-to-Energize outputs

No auxiliary output

Semi-flush mounting

display and high-speed trip

OP

Figure 1-1. Style Number Identification Chart

1-4 BE1-87T General Information 9171300990 Rev V

Specifications

I

K

t

=

Maximum

I

Minimum Pi

ckup

Percent of

Slope

Restraint

=

Minimum Pi

ckup

Percent of

Slope

=

=

0.35

20

1.75

%

The BE1-87T relay is available in either single-phase or three-phase configurations and with the following
features and capabilities.

Current Sensing Inputs

Maximum Current Per Input

1 Ampere CT Units 4 A continuous; 50 A or 50 X tap (whichever is less) for 1 second.

5 Ampere CT Units 20 A continuous; 250 A or 50 X tap (whichever is less) for 1

For ratings other than one second, the rating may be calculated as:

Where:

Current Sensing Burden

Tap Setting Control (Scaling)

1 Ampere CT Units 0.4 to 1.78 in 0.02 A increments.

5 Ampere CT Units 2.0 to 8.9 A, in 0.1 A increments.

The unit is designed to operate from the secondary of current
transformers rated at either 1 A or 5 A. Frequency range is ±5 Hz of
nominal.

second.

t is the time (in seconds) that the current flows

K = 50 A or 50 X tap, whichever is less (1 Amp CT Units), or

K = 250 A or 50 X tap, whichever is less (5 Amp CT Models)

Less than 0.02 ohm per phase.

Front panel rotary switches, labeled INPUT, permit scaling the
sensed input current (or tap setting) over the range of:

Restrained Output

Pickup Range Front panel thumbwheel switches adjust pickup of the restrained

Pickup Accuracy

Minimum Pickup

For example:

output as a percentage of the through current. The range is 15 to
60% of the operating current in 5% increments.

±6% of pickup ±100 mA (5 Ampere Units) or ±20 mA (1 Ampere
units).

0.35 ±6% of tap setting. Refer to Tabl e 1-1 and Figure 1-2. Table 1-1
provides calculated intersection points of the slope characteristic
and the minimum pickup (in multiples of tap) as shown in Figure
1-2. The calculation was derived from the formula:

The relay operates when the per unit difference current (operating
current) is above the 0.35 pu or the slope line in Figure 1-2.
Calculation examples are found in Section 5.

9171300990 Rev V BE1-87T General Information 1-5

Table 1-1. Multiples of Tap

Front Panel Setting % 15 20 25 30 35 40 45 50 55 60

Maximum Restraint
Current At Minimum
Pickup In Multiples of
Tap

2.33 1.75 1.40 1.17 1.00 0.875 0.778 0.700 0.636 0.583

Figure 1-2. Percentage Restraint Characteristic

Second-Harmonic Restraint Inhibit of the restrained output occurs when the second-

harmonic component exceeds a pickup setting which is 12%
of the operating current for single-phase units or 18% for
three-phase units.

Fifth-Harmonic Restraint Inhibit of the restrained output occurs when the fifth-harmonic

component exceeds a pickup setting which is 35% of the
operating current.

Unrestrained Output

Pickup Range Front panel thumbwheel switches adjust the pickup point of

Pickup Accuracy

the unrestrained output over a range of 6 to 21 times the tap
setting in increments of 1 x Tap.

±3% of the front panel setting.

1-6 BE1-87T General Information 9171300990 Rev V

Outputs

Resistive

120/240 Vac Make 30 A for 0.2 seconds, carry 7 A continuously and break

250 Vdc Make and carry 30 A for 0.2 seconds, carry 7 A continuously

500 Vdc Make and carry 15 A for 0.2 seconds, carry 7 A continuously

Inductive

120/240 Vac, 125/250 Vdc Make and carry 30 A for 0.2 seconds, carry 7 A continuously

Output contacts are rated as follows.

7 A.

and break 0.3 A.

and break 0.1 A.

and break 0.3 A, (L/R = 0.04).

Target Indicators

Single-Phase Units Either an internally-operated or a current-operated target is

Three-Phase Units Either internally operated or current operated targets (as

Harmonic Attenuation

Parameter

(50 Or 60 Hz Models)

Through Current 0 0 0 0 12 dB

Operating Current 0 0 0 0 12 dB

2nd Harmonic Restraint 12 dB 0 12 dB 12 dB 12 dB

5th Harmonic Restraint 12 dB 12 dB 12 dB 0 12 dB

Target indicators may be either internally-operated or current­operated (operated by a minimum of 0.2 A through the output
trip circuit). When the target is current-operated, the
associated output circuit must be limited to 30 A for 0.2
seconds, 7 A for 2 minutes and 3 A continuously.

supplied (as selected by the Style Number) for each trip
output (i.e., the restrained and the unrestrained functions).

selected) indicate the function (restrained or unrestrained)
that caused the trip, and the tripped phase (A, B, C).

Refer to Tabl e 1-2.

Table 1-2. Harmonic Attenuation

Minimum Attenuation at Indicated Fundamental

50/60 Hz 100/120 Hz 150/180 Hz 250/300 Hz 500 Hz

9171300990 Rev V BE1-87T General Information 1-7

Timing

(For 60 Hz units only)

Refer to Figure 1-3 for Unrestrained Response Times and
Restrained Response Times.

Figure 1-3. Unrestrained Response Times and Restrained Response Times

1-8 BE1-87T General Information 9171300990 Rev V

Isolation

In accordance with IEC 255-5 and ANSI/IEEE C37.90-1989,
one minute dielectric (high potential) tests, as follows:

All circuits to ground: 2,121 Vdc

Input to output circuits: 1,500 Vac or 2,121 Vdc

Power Supply

Type

K (midrange) 48 Vdc 24 to 150 Vdc 9.0 W

J (midrange)

L (low range) 24 Vdc 12 to 32 Vdc * 9.0 W

Y (midrange)

Z (high range)

* Type L power supply initially requires 14 Vdc to begin operating. Once operating, the input voltage may
be reduced to 12 Vdc and operation will continue.

Surge Withstand Capability

Refer to Tabl e 1-3.

Table 1-3. Power Supply Ratings

Nominal

Input Voltage

125 Vdc 24 to 150 Vdc 9.0 W

120 Vac 90 to 132 Vac 21.0 VA

48 Vdc 24 to 150 Vdc 8.5 W

125 Vdc 24 to 150 Vdc 9.0 W

250 Vdc 68 to 280 Vdc 9.5 W

240 Vac 90 to 270 Vac 28.0 VA

Qualified to ANSI/IEEE C37.90.1-1989, Standard Surge
Withstand Capability (SWC) Tests for Protective Relays and
Relay Systems, and IEC 255-5 Impulse Test and Dielectric
Tes t.

Input Voltage Range

Burden at

Nominal

Radio Frequency Interference
(RFI)

UL Recognition

GOST-R Certification

Patent

Shock

Vibration

Operating Temperature

Storage Temperature

Maintains proper operation when tested in accordance with
IEEE C37.90.2-1987, Trial-Use Standard Withstand
Capability of Relay Systems to Radiated Electromagnetic
Interference from Transceivers.

UL Recognized per Standard 508, UL File No. E97033. Note:
Output contacts are not UL Recognized for voltages greater
than 250 V.

GOST-R certified per the relevant standards of Gosstandart
of Russia.

Patented in U.S., 1991, U.S. Patent No. 5014153.

Patented in Canada, 1993.

In standard tests, the relay has withstood 15 g in each of
three mutually perpendicular axes without structural damage
or degradation of performance.

In standard tests, the relay has withstood 2 g in each of three
mutually perpendicular axes swept over the range of 10 to
500 Hz for a total of six sweeps, 15 minutes each sweep,
without structural damage or degradation of performance.

–40°C (–40°F) to 70°C (158°F)

–65°C (–85°F) to 100°C (212°F)

9171300990 Rev V BE1-87T General Information 1-9

Weight

22.3 lbs (10.1 kg) maximum (three-phase unit)

Case Size

19.5 lbs (8.85 kg) maximum (single-phase unit)

All units are supplied in an M1 case size. See Section 4,
Installation for case dimensions.

1-10 BE1-87T General Information 9171300990 Rev V

SECTION 2 • CONTROLS AND INDICATORS

TABLE OF CONTENTS

SECTION 2 • CONTROLS AND INDICATORS ........................................................................................ 2-1

Location of Controls and Indicators ....................................................................................................... 2-1

Figures

Figure 2-1. Sensing Input Range 1 or 3 Three-Phase, Three Inputs ........................................................ 2-4

Figure 2-2. Sensing Input Range 1 or 3, Single-Phase, Five Inputs ......................................................... 2-5

Figure 2-3. Sensing Input Range 2 or 4, Three-Phase, Two Inputs .......................................................... 2-6

Figure 2-4. Controls Mounted Inside the Relay ......................................................................................... 2-7

Figure 2-5. Sensing Input Range 2 or 4, Option 1-1, Single-Phase, Five Inputs, % OF TRIP Option ...... 2-8

Tables

Table 2-1. Controls and Indicators ............................................................................................................ 2-1

9171300990 Rev V BE1-87T Controls and Indicators i

ii BE1-87T Controls and Indicators 9171300990 Rev V

SECTION 2 • CONTROLS AND INDICATORS

Location of Controls and Indicators

Table 2-1 lists and briefly describes the operator controls and indicators of the BE1-87T Transformer
Differential Relay. Reference the call-out letters A through M to Figures 2-1 to 2-3; N through Q to Figure
2-5. Exploded views of controls that are mounted inside the relay (call-out letters B, D and I) are shown in
Figure 2-4.

Table 2-1. Controls and Indicators

Letter Control or Indicator Function

A INPUT (or TAP) Switches Front panel INPUT switches are used to scale the

transformer currents. There are two of these rotary
switches for each input.

1 Ampere CT Units

5 Ampere CT Units

B 30° Phase Shift Jumpers

(three-phase units ONLY)

C

D CALIBRATE Switch

E POWER Indicator

UNRESTRAINED PICKUP
LEVEL Switches

(three-phase units ONLY)

Each of the upper switches is calibrated to represent
the tenths and units digits (0.4 through 1.6) of tap
value. Each of the lower switches is calibrated to
represent two-hundredths of tap value for each
increment. Always add the setting of the lower switch to
that of the upper switch. For example, if a setting of

1.02 is desired, the upper switch must be at 1.0 and the
lower switch must be at 0.02. The total setting range for
each input is 0.4 to 1.78.

Each of the upper switches is calibrated to represent
the units digit (2 through 8) of tap value. Each of the
lower switches is calibrated to represent tenths of tap
value. Always add the setting of the lower switch to that
of the upper switch. For example, if a setting of 5.0 is
desired, the upper switch is set to 5.0, the lower switch
must be at 0.0. The total setting range for each input is

2.0 to 8.9.

These jumpers control the internal phase shift of the
relay, either +30°, -30°, or 0°, depending upon the
position of the jumpers provided for each input on the
Analog #2 Board, shown in Figure 2-4. Additional
information is in Section 4.

This thumbwheel switch establishes the desired pickup
setting for all phases of the unrestrained output. The
adjustment range is from 6 to 21 times the phase tap
setting, in increments of 1.

A two-position switch is located on each Analog #1
Board and is easily accessible on the right side of the
relay when it is withdrawn from the case. In the
CALIBRATE position, these switches inhibit the
harmonic share feature when calibrating the 2nd
Harmonic Restraint. In the NORMAL position, the relay
will operate normally.

This LED will illuminate when operating power is
supplied to the internal circuitry of the relay.

9171300990 Rev V BE1-87T Controls and Indicators 2-1

Letter Control or Indicator Function

F

G FUNCTION Targets Option

H Target Reset Switch

I Auxiliary Relay Control

J ELEMENT Targets Option

K

L UNREST. TRIP Indicator

M REST. TRIP Indicator

N M Indicator Red LED lights when the % OF TRIP pushbutton P is

O S Indicator Red LED lights when the % OF TRIP pushbutton P is

P Percent of Trip Pushbutton Pushbutton that is used to activate the % of TRIP

PUSH-TO-ENERGIZE
OUTPUT Switches Option

Switches Option

(three-phase units ONLY)

RESTRAINED PICKUP
LEVEL Switches

Two momentary pushbutton switches are accessible by
inserting a 1/8 inch diameter non-conducting rod
through access holes in the front panel. Switch R,
when actuated, closes the Restrained Output Relay
contacts. Switch U, when actuated, closes the
Unrestrained Output Relay contact(s).

NOTE

The optional Auxiliary Relay contacts (Option 3-1, 3-2
or 3-5) will also be operated by the PUSH-TO-
ENERGIZE switches if enabled by the two internal
Auxiliary Relay Control Switches. (Refer to LETTER I.)

Electronically-latched LED targets that indicate an
unrestrained or restrained output has occurred.

Resets the electronically-latched targets.

Two internal slide switches, S1 and S2, enable the
optional Auxiliary Output Relay to close only when a
restrained output occurs (S1 ON), only when an
unrestrained output occurs (S2 ON), or to close when
either output occurs (S1 and S2 ON).

When shipped from the factory, the Auxiliary Relay will
be configured with S1 and S2 ON.

NOTE

The switches are located on the mother board and are
only accessible by withdrawing the relay case.

Electronically-latching LED targets indicate the phase
that caused a trip operation.

Thumb-wheel switches (one per phase element) are
used to adjust the desired percent of allowable
through-current restraint from 15 to 60 % in 5 %
increments. (Through-current is the greatest relative
individual input current.)

The through-current restraint characteristic is
individually adjustable for phases A, B, and C.

In a three-phase unit, all three switches are typically
kept at identical settings.

Red LED lights when there is an unrestrained pickup.

Red LED lights when there is a restrained pickup.

pressed and the restraint current is below the slope
characteristic kneepoint as defined in Table 1-1. That
is, the relay will operate at minimum pickup (0.35 times
tap).

pressed and the restraint current is above the slope
characteristic kneepoint as defined in Table 1-1. That
is, the relay will operate based on the restraint
characteristic.

LEDs.

2-2 BE1-87T Controls and Indicators 9171300990 Rev V

Letter Control or Indicator Function

Q % OF TRIP Indicators Option When the % OF TRIP pushbutton P is pushed, eight

LEDs, shown in Figure 2-5, are used to indicate the
approximate percentage of operating current to:

Minimum pickup (LED M also lights); or
Slope characteristic pickup (LED S also lights).
The eight LEDs represent the following approximate

percentages.
1 LED: 3% (Yellow LED)
2 LEDs: 7% (Yellow LED)
3 LEDs: 11% (Yellow LED)
4 LEDs: 20% (Red LED)
5 LEDs: 40% (Red LED)
6 LEDs: 60% (Red LED)
7 LEDs: 80% (Red LED)
8 LEDs: 100% (Red LED)
A bar chart above the LEDs shows the relative

percentage of trip.

9171300990 Rev V BE1-87T Controls and Indicators 2-3

Figure 2-1. Sensing Input Range 1 or 3 Three-Phase, Three Inputs

2-4 BE1-87T Controls and Indicators 9171300990 Rev V

Figure 2-2. Sensing Input Range 1 or 3, Single-Phase, Five Inputs

9171300990 Rev V BE1-87T Controls and Indicators 2-5

Figure 2-3. Sensing Input Range 2 or 4, Three-Phase, Two Inputs

2-6 BE1-87T Controls and Indicators 9171300990 Rev V