Basler Electric BE1-87T User Manual

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INSTRUCTION MANUAL

FOR

TRANSFORMER DIFFERENTIAL RELAY

BE1-87T

TRANSFORMER DIFFERENTIAL

Style No. D2E A1J D1S0F

Serial No. XXXXXXXXXXXX

PUSH TO

ENERGIZE

OUTPUT

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

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, info@basler.com

PHONE +1 618.654.2341 FAX +1 618.654.2351

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.

 Updated 2

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

 Updated formatting to current style used.

 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

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

 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

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

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

Figure 1-1. Style Number Identification Chart

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

Specifications

Maximum

Minimum Pi

ckup

Percent of

Slope

Restraint

Minimum Pi

ckup

Percent of

Slope

0.35

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)

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

G FUNCTION Targets Option

H Target Reset Switch

I Auxiliary Relay Control

J ELEMENT Targets Option

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

SECTION OF THE (VERTICAL)

MOTHER BOARD AT LEFT

REAR OF RELAY

AUX

UNRES

AUX RES

CR19

CR7

LH EDGE OF ANALOG #2 BOARD (THE 4TH BOARD

DOWN, COUNTING THE

MAGNETIC BOARD.)

J11

VR2

TP+12V

J10

∆

WYE

∆

WYE

∆

WYE

P0052-26

BE1-87T

Figure 2-4. Controls Mounted Inside the Relay

9171300990 Rev V BE1-87T Controls and Indicators 2-7

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

2-8 BE1-87T Controls and Indicators 9171300990 Rev V

SECTION 3 • FUNCTIONAL DESCRIPTION

TABLE OF CONTENTS

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

General .................................................................................................................................................. 3-1

Description ............................................................................................................................................. 3-1

Current Transformers ......................................................................................................................... 3-1

Scaling ................................................................................................................................................ 3-1

Summing ............................................................................................................................................ 3-1

30° Internal Phase Shift (Three-Phase Relays ONLY) ...................................................................... 3-1

Restrained Trip Output ....................................................................................................................... 3-3

Unrestrained Trip Output .................................................................................................................... 3-3

Auxiliary Relay Option ........................................................................................................................ 3-4

Power Supply ..................................................................................................................................... 3-4

Power Supply Status Output (Optional) ............................................................................................. 3-4

Target Indicators (Optional)................................................................................................................ 3-4

% of Trip ............................................................................................................................................. 3-5

Figures

Figure 3-1. Functional Block Diagram ....................................................................................................... 3-2

Figure 3-2. Functional Block Diagram, Phase B and Phase C ................................................................. 3-2

9171300990 Rev V BE1-87T Functional Description i

ii BE1-87T Functional Description 9171300990 Rev V

SECTION 3 • FUNCTIONAL DESCRIPTION

General

BE1-87T relays are solid-state devices that protect transformers by providing output contact closure when the scaled current into the protected transformer does not equal the scaled current out, within defined limits. These relays are harmonically restrained to prevent tripping during initial energization and external fault conditions. A through-current restraint also provides security against tripping for external faults. An unrestrained tripping element is included to provide a high-speed trip in the event of a particularly severe fault within the transformer.

Description

The functional block diagrams of Figures 3-1 and 3-2 illustrate the overall operation of the BE1-87T Transformer Differential Relay. (Figure 3-1 shows Phase A or single-phase functions; Figure 3-2 shows the additional functions for phases B and C.) Since the three phases are functionally similar, only phase A is shown in detail in Figure 3-1. Note that in a three-phase unit, there may be one restrained output for each phase (Output Type Option E in the third position of the Style Number), or one restrained output that serves for all three phases (Option F in the third position). When Target Option C or D is specified for a three-phase Unit (in the seventh position), an individual target is supplied for each phase.

Current Transformers

In the protected zone of the power system, CTs with a 1 ampere or 5 ampere secondary winding supply

not

the sensing current for each input. This is connected ahead of the BE1-87T. Sensing currents are, in turn, applied to relay internal input transformers. These transformers provide system isolation.

shown in Figure 3-1 or Figure 3-2. Other relays may be

Scaling

Input currents are scaled by the front panel INPUT rotary switches that introduce resistances to the internal CT secondaries. The switches are calibrated in 0.02 ampere increments from 0.4 to 1.78 ampere for 1 ampere CT units (Options 2 or 4 in the second position of the Style Number), and in 0.1 ampere increments from 2.0 to 8.9 amperes for 5 ampere CT models (Options 1 or 3 in the second). The many graduations of adjustment are provided to allow each input to approach an ideal representation of the actual operating per unit value.

Summing

Analog signals representing each input contribution are vector summed (shown as Summing in Figure 3-

1). This summing process produces the operating current (I currents.

Ideally, and with perfectly matched CTs, a transformer without an internal fault should cause I exactly zero on a continuous basis. When not zero, a fault would be indicated. However, saturation effects caused by heavy through-current or magnetic inrush can cause a temporary imbalance even though no internal fault has occurred. To prevent a false trip under such conditions, various types of restraint are used. Each restraint is specific to a potential cause of misoperation. These are individually discussed in the topic Restrained Trip Output.

) that is the phasor sum of the input

to be

30° Internal Phase Shift (Three-Phase Relays ONLY)

For three-phase units, the inputs to the Summing function are first routed through the 30° Phase Shift circuit. There the signals may be advanced or retarded by 30° or passed through unchanged. Compensating phase shift direction (shown as the Phase Shift Setting circuit in Figure 3-1) is determined by the position of three jumpers on the internal Analog #2 Board. (The location of these jumpers is shown in Figure 2-4.) The internal phase shift will accomplish the corresponding zero sequence blocking. The current magnitude will be increased by later in detail in Section 4).

and must be taken into account in the tap setting (explained

9171300990 Rev V BE1-87T Functional Description 3-1

Figure 3-1. Functional Block Diagram

RESTRAINED

UNRESTRAINED

RESTRAINED

UNRESTRAINED

TARGET

B SAME AS A

C0C SAME AS A

OPTIONAL

RESTRAINED

CONTACTS

FOR EACH OF

3 PHASES

(SEE NOTE

BE1-87T

D741-001b

7-11-94

COM.

IN. 1

IN. 2

IN. 3

COM.

IN. 1

IN. 2

IN. 3

IN. 3, B SCALE

IN. 3, C SCALE

IN. 1, B SCALE

IN. 1, C SCALE

OPERATING

POWER

SUPPLY

POWER

SUPPLY

STATUS

REST.

TRIP

AUX.

OPTION

UNREST

TRIP

TARGET

UNRESTRAINED

RESTRAINED

POWER

TO INTERNAL

CIRCUITRY

Iop1

SHIFT SETTING:

+30

, -30

, 0

LEDs

CALCULATE

MAXIMUM

INDIVIDUAL

CURRENT

THEN TRIP

max

% OF

TRIP

UNREST. SETTING

COM.

IN. 1

IN. 2

IN. 3

IN. 4

IN. 5

TO OTHER PHASES

(THREE-PHASE ONLY)

UNREST

TRIP

(6 TO 21

TIMES TAP)

SHIFT

(ONLY ON

3 UNITS)

SCALING

( TAP)

SCALING

( TAP)

SCALING

( TAP)

IN. 2, B SCALE

IN. 2, C SCALE

SCALING

( TAP)

C05TH >

SETTING

=INHIBIT

2ND >

SETTING

=INHIBIT

C00

TARGET

SCALING

( TAP)

POWER

SUPPLY

SENSOR

FIFTH

HARMONIC

RESTRAINT

FILTERS

SECOND

HARMONIC

RESTRAINT

FILTERS

SUMMING:

ALGEBRAIC

SUM OF

INPUTS =

OPERATING

CURRENT

( )

SHIFT

(ONLY ON

3 UNITS)

SHIFT

(ONLY ON

3 UNITS)

max

% I

max

REST.

PICKUP

CONTROL

% I

max

UNREST.

SETTING

THEN TRIP

IF I >

BE1-87T

D741-001a

7-11-94

NOTES

1 Present in three-phase units ONLY. 2 Inputs 4 and 5 are available in single-phase units ONLY. 3 The settings are calibrated to a specified percentage of the harmonic to the fundamental. See Harmonic

Restraints for factory settings. 4 Phase Targets are supplied on three-phase units ONLY. 5 Restrained Trip Contact:

• One contact for single-phase units.

• One contact or one contact per phase available on three-phase units.

6 Three-phase units use the sum of the second harmonic from each phase to restrain each phase.

7 Phase Targets are supplied on three-phase units ONLY.

8 Restrained Trip Contact:

• One contact for single-phase units.

• One contact or one contact per phase available on three-phase units.

3-2 BE1-87T Functional Description 9171300990 Rev V

Figure 3-2. Functional Block Diagram, Phase B and Phase C

Restrained Trip Output

Restrained trip output contacts are subject to three types of restraint (i.e., inhibit) signals:

• Percentage restraint

• Second-harmonic restraint

• Fifth-harmonic restraint

These signals are developed within the relay in response to external conditions and block the restrained output contacts from closing.

Percentage Restraint

Percentage restraint developed from the maximum through current and the slope setting determines the minimum operating current I produce a Restraint Trip output. The I

(Figure 3-1) in a comparator where I

desired trip level is adjustable on the front panel RESTRAINED

PICKUP LEVEL switches shown in Figures 2-1 through 2-3.

Comparators in the Calculate Max. Individual Current circuit determine which input (of a particular phase) is receiving the greatest current. That input is chosen and then called the I then scaled by the front panel RESTRAINED PICKUP LEVEL switches (shown as the Restrained Pickup Control in Figure 3-1). The resulting signal (%I extended to the Then Trip comparator and the I

The Then Trip circuitry compares the operating current (I than %I

(and there is no 5th or 2nd harmonic restraint to cause an inhibit as described below), a

MAX

), that represents the percentage of through-current is

MAX

Divided By %I

MAX

) to %I

function.

Restrained Trip output is produced.

Divided By %I

. If IOP is greater than the preset percent of %I

MAX

contains eight comparators and compares IOP to the preset percentage levels of

MAX

for a specific comparator, the LED associated with

MAX

that comparator lights. The eight LEDs represent the following approximate percentages:

First LED: 3%

Second LED: 7%

Third LED: 11%

Fourth LED: 20%

Fifth LED: 40%

Sixth LED: 60%

Seventh LED: 80%

Eighth LED: 100%

must be greater than %I

signal. The I

MAX

. If the operating current is greater

MAX

output is

MAX

NOTE

As each successive LED lights, all previous or lesser percentage value LEDs will also light.

Harmonic Restraints

Development of a restrained trip output may be inhibited by either of two harmonic restraints. These are generated by bandpass filters tuned to the second and fifth harmonics of the operating current. Comparators monitor these signals. When the fifth-harmonic content exceeds 35% of the operate current (indicating overexcitation of the transformer) or when the second-harmonic content exceeds 12% (singlephase) or 18% (three-phase) of the operate current (indicating a magnetic inrush condition), an inhibit signal is developed that blocks operation of the Restrained Trip output contact. (Stated percentages represent the factory setting.)

Unrestrained Trip Output

IOP is also compared against a reference established by the front panel UNRESTRAINED PICKUP LEVEL switch is shown in Figures 2-1 through 2-5. When this reference is exceeded, the Unrestrained

Tr i p output relay is energized. An unrestrained trip is not affected by through-current or harmonic inhibits.

9171300990 Rev V BE1-87T Functional Description 3-3

Auxiliary Relay Option

Auxiliary relays (Option 3-1, 3-2 or 3-5 in the tenth position of the Style Number) are accompanied by two switches, S1 and S2, which allow the relays to respond to a restrained trip (S1 ON) or to an unrestrained trip (S2 ON), or both (S1 and S2 ON). These switches (letter I of Figure 2-4 and described in Table 2-1) are located on the mother board and are shipped in the ON position. Auxiliary relays may be disabled by opening both switches (S1 and S2 OFF).

Power Supply

Relay operating power is developed by a wide-range, isolated, low-burden, switching power supply that delivers ±12 Vdc to the relay’s internal circuitry. The power supply is not sensitive to the input power polarity. A front panel LED power indicator lights to indicate that the power supply is functioning properly.

Style number designations and input voltage ranges for the available power supply models are provided in Section 1, General Information.

Power Supply Status Output (Optional)

The Power Supply Status output relay has normally closed (NC) contacts. The relay is energized by the presence of nominal voltage at the output of the power supply. Normal operating voltage then keeps the relay continuously energized and its contacts open. However, if the power supply voltage falls below requirements, the Power Supply Status output relay will de-energize and close the contacts.

The Power Supply Status output is not associated with any magnetically latched target. The POWER LED on the front panel provides a visual indication of the normal operating status of the power supply.

NOTE

Sensing Input Types A through E (first position of the Style Number) have paddle-operated shorting bars included in the relay case (terminals 19 and 20) so that the Power Supply Status output terminals can provide a remote indication that the BE1-87T has been withdrawn from its case or that it has been taken out of service by removing the connection plugs. Sensing Input Type G relays do NOT have shorting bars on the Power Supply Status output. Sensing Input Type G units use terminal 9 (lower terminal block) and terminal 19 (upper terminal block) for the Power Supply Status output.

Target Indicators (Optional)

When the Target option is specified as either C or D, shown in the seventh position of the Style Number, electronically latched indicators, labeled FUNCTION, are incorporated in the front panel. The electronically latched and reset targets consist of red LED indicators. The appropriate target is tripped when either a restrained (R) or unrestrained (U) output occurs. Latched targets are reset by operating the target reset switch on the front panel. If relay operating power is lost, any illuminated (latched) targets are extinguished. When relay operating power is restored, the previously latched targets are restored to their latched state.

When targets are specified for three-phase relays, three additional ELEMENT targets are incorporated to indicate the phase involved. Only the FUNCTION targets, restrained (R) or unrestrained (U) are available for single-phase units.

Relays can be equipped with either internally operated targets (Type C) or current operated targets (Type D). Both target types are reset by operating the target reset switch.

• Type C target (referred to as internally operated) is actuated by an integral driver circuit that

responds directly to the relay internal logic. This type of target is tripped regardless of the amount of current flowing through the associated output contact.

• Type D target (referred to as current operated) is actuated when a minimum of 0.2 A flows

through the associated output contacts. To accomplish this, a special reed relay is placed in series with the contact to signal the target indicator. (The series impedance of the reed relay is less than 0.1 ohm.) Current in the output circuit must be limited to 30 amperes for 0.2 seconds, 7 amperes for 2 minutes and 3 amperes continuously.

3-4 BE1-87T Functional Description 9171300990 Rev V

NOTE

87T target indicators consisted of

Prior to September 2007, the BE1magnetically latched, disc indicators. These mechanically latched target indicators have been replaced by the electronically latched LED targets in use today.

% of Trip

When the % of trip pushbutton Q is pushed, eight LEDs, shown in Figure 2-5, are used to indicate the 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 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 Functional Description 3-5

3-6 BE1-87T Functional Description 9171300990 Rev V

SECTION 4 • INSTALLATION

TABLE OF CONTENTS

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

General .................................................................................................................................................. 4-1

Relay Operating Precautions ................................................................................................................. 4-1

Mounting ................................................................................................................................................ 4-2

Dielectric Test ........................................................................................................................................ 4-9

Connections ........................................................................................................................................... 4-9

Relay Disassembly .............................................................................................................................. 4-17

Precautions ...................................................................................................................................... 4-17

Circuit Board Removal Procedure .................................................................................................... 4-17

Disabling Unused Inputs ...................................................................................................................... 4-18

Single-Phase Units ........................................................................................................................... 4-20

Three-Phase Units ........................................................................................................................... 4-20

Sensing Connection Diagrams ............................................................................................................ 4-20

Single-Phase Input Sensing Connections ........................................................................................ 4-20

Three-Phase Input Sensing Connections ........................................................................................ 4-24

Setting the BE1-87T ............................................................................................................................. 4-33

Method.............................................................................................................................................. 4-33

Procedure One ................................................................................................................................. 4-33

Procedure Two ................................................................................................................................. 4-42

Checking the Relay Settings and System Inputs ................................................................................. 4-49

Maintenance......................................................................................................................................... 4-50

Storage ................................................................................................................................................. 4-50

Test Plug .............................................................................................................................................. 4-51

Figures

Figure 4-1. Panel Cutting/Drilling, Semi-Flush, M1 Case .......................................................................... 4-2

Figure 4-2. M1 Case Dimensions, Rear View, Double Ended, Semi-Flush Mount ................................... 4-3

Figure 4-3. M1 Case Dimensions, Side View, Double Ended, Semi-Flush Mount Figure 4-4. Panel Cutting/Drilling, Double Ended, Projection Mount, M1 Case Figure 4-5. M1 Case Dimensions, Rear View, Double Ended, Projection Mount Figure 4-6. M1 Case Dimensions, Side View, Double Ended, Projection Mount Figure 4-7. M1 Case Cover Dimensions, Front View Figure 4-8. Case Terminals: Single-Phase Figure 4-9. Case Terminals: Three-Phase, Two Input (Sensing Input Type E), Output Option E Figure 4-10. Case Terminals: Three-Phase, Two Input (Sensing Input Type E), Output Option F Figure 4-11. Case Terminals: Three-Phase, Three Input (Sensing Input Type G), Output Option E Figure 4-12. Internal Connections: Single-Phase, Five Input (Sensing Input Type D), Output Option E Figure 4-13. Internal Connections: Three-Phase, Two Input (Sensing Input Type E), Output Option E Figure 4-14. Internal Connections: Three-Phase, Two Input (Sensing Input Type E), Output Option F Figure 4-15. Internal Connections: Three-Phase, Three Input (Sensing Input Type G), Output Option E 15 Figure 4-16. Control Circuits: Single-Phase, Output Option E Figure 4-17. Control Circuits: Three-Phase, Two Input (Sensing Input E), Output Option E Figure 4-18. Control Circuits: Three-Phase, Two Input (Sensing Input E), Output Option F Figure 4-19. Control Circuits: Three-Phase, Three Input (Sensing Input G), Output E Figure 4-20. Side View of Cradle Assembly Figure 4-21. Unused Input-Disabling Jumpers, Analog #1 Board: Option 1-0 Figure 4-22. Unused Input-Disabling Jumpers, Analog #1 Board: Option 1-1 Figure 4-23. Typical Single-Phase Sensing Connections

Figure 4-24. Single-Phase Connections, Delta-Wye Configuration ........................................................ 4-21

Figure 4-25. Single-Phase Connections, Wye-Wye Configuration Figure 4-26. Single-Phase Connections, Delta-Delta-Wye Configuration Figure 4-27. Single-Phase Connections, Delta-Wye Configuration With Two Load Busses Figure 4-28. 30° Phase Shift Compensation Jumpers

. 4-

................................... 4-4

........................................ 4-5

..................................... 4-6

...................................... 4-7

................................................................................ 4-8

............................................................................................... 4-9

.......... 4-10

........ 4-10

..... 4-11

4-12 4-13 4-14

................................................................ 4-15

.................. 4-16

.......................... 4-17

............................................................................................ 4-18

........................................ 4-19

....................................................................... 4-21

......................................................... 4-22

............................................... 4-23

.................. 4-24

............................................................................ 4-26

9171300990 Rev V BE1-87T Installation i

Figure 4-29. Three-Phase Connections, Delta-Wye Configuration, CT Compensation .......................... 4-27

Figure 4-30. Three-Phase Connections, Delta-Wye Configuration, Internal Phase Compensation Figure 4-31. Three-Phase Connections, Wye-Delta Configuration, Internal Phase Compensation Figure 4-32. Three-Phase Connections, Delta-Delta Configuration Figure 4-33. Three-Phase Connections, Wye-Wye or Autotransformer Configuration, CT Compensation 30 Figure 4-34. Three-Phase Connections, Wye-Wye or Autotransformer Configuration, Internal Phase Compensation Figure 4-35. Three-Phase Connections, Autotransformer With Loaded Delta Tertiary Figure 4-36. Application Example: Autotransformer With Tertiary Winding Figure 4-37. Slope Needed to Accommodate Total Mismatch with Adequate Margin Figure 4-38. Two Winding Transformer Relay Setting Calculation Example

Tables

Table 4-1. List of Variables ...................................................................................................................... 4-34

Table 4-2. Examples of Suitable Slope Settings Table 4-3. Single-Phase Input Terminals Table 4-4. Input Conditions For Non-Trip Three-Phase Sensing

....... 4-27

....... 4-28

........................................................ 4-29

.......................................................................................................................................... 4-31

.......................... 4-32

............................................ 4-35

............................ 4-40

.......................................... 4-42

..................................................................................... 4-41

................................................................................................ 4-49

............................................................ 4-50

ii BE1-87T Installation 9171300990 Rev V

SECTION 4 • INSTALLATION

General

When not shipped as part of a control or a switchgear panel, the relay is shipped in a sturdy carton to prevent damage during transit. Immediately upon receipt of a relay, check the model and Style Number against the requisition and packing list to see that they agree. Visually inspect the relay for damage that may have occurred during shipment. If there is evidence of damage, immediately file a claim with the carrier and notify the Regional Sales Office, or contact a sales representative at Basler Electric, Highland, Illinois.

In the event the relay is not to be installed immediately, store the relay in its original shipping carton in a moisture- and dust-free environment. For more information, see Storage in Section 4. When the relay is to be placed in service, it is recommended that the Verification Tests, shown in Section 5, be performed prior to installation.

Relay Operating Precautions

Before installation or operation of the relay, note the following precautions.

1. A minimum of 0.2 A in the output circuit is required to ensure operation of current-operated targets.

2. The relay is a solid-state device and has been type tested in accordance with the requirements defined under Dielectric Test. If a wiring insulation test is required on the panel assembly in which the relay is to be installed, it is suggested that the connection plugs (or paddles) of the relay be removed and the cradle withdrawn from the case so as not to produce false readings during the wiring insulation test.

3. When the connection plugs are removed, the relay is disconnected from the operating circuit and will not provide system protection. Always be sure that external operating (monitored) conditions are stable before removing a relay for inspection, testing, or servicing. Be sure that connection plugs are in place before replacing the front cover.

CAUTION

To prevent possible false tripping, the upper connection plug should be in place prior to removing or installing the lower connection plug.

4. Thumbwheel switches should not be changed while the relay is in service. Momentary undesired indications and outputs may occur.

WARNING!

The TEST PROCEDURES require familiarity with solid-state relay circuits. To avoid personal injury or equipment damage, do not proceed unless qualified in this area.

NOTE

Several procedures in this manual require the removal of printed circuit boards. Refer to the topic Relay Disassembly before installing the BE1-87T.

9171300990 Rev V BE1-87T Installation 4-1

Mounting

14.63

P0066-74

Because the BE1-87T, Transformer Differential Relay, is of solid-state design. It does not have to be mounted vertically. Any convenient mounting angle may be chosen. The BE1-87T relay is supplied in a standard M1 size drawout case and can be either semi-flush or projection mounted (Option 4). Refer to Figures 4-1 through 4-7 for outline dimensions and panel drilling diagrams.

Figure 4-1. Panel Cutting/Drilling, Semi-Flush, M1 Case

4-2 BE1-87T Installation 9171300990 Rev V

Figure 4-2. M1 Case Dimensions, Rear View, Double Ended, Semi-Flush Mount

9171300990 Rev V BE1-87T Installation 4-3

P0066-76

10-32 SCREWS

MOUNTING PANEL

2.195

(55.75)

.31

(7.9)

.31

(7.9)

.75

(19.1)

6.19

(157.2)

1.95

(49.53)

7.03

(178.56)

7.03

(178.56)

Figure 4-3. M1 Case Dimensions, Side View, Double Ended, Semi-Flush Mount

4-4 BE1-87T Installation 9171300990 Rev V

Figure 4-4. Panel Cutting/Drilling, Double Ended, Projection Mount, M1 Case

9171300990 Rev V BE1-87T Installation 4-5

Figure 4-5. M1 Case Dimensions, Rear View, Double Ended, Projection Mount

4-6 BE1-87T Installation 9171300990 Rev V

P0066-78

10-32 SCREWS

2.195

(55.75)

.31

(7.9)

.31

(7.9)

.75

(19.1)

6.19

(157.2)

1.95

(49.53)

7.03

(178.56)

7.03

(178.56)

TERMINAL EXTENTION (TYP.) FOR DETAILED INSTRUCTIONS, SEE THE TERMINAL PROJECTION MOUNTING KIT SUPPLIED.

.25

(6.4)

5/16-18 STUD 2 PLACES

MOUNTING PANEL

Figure 4-6. M1 Case Dimensions, Side View, Double Ended, Projection Mount

9171300990 Rev V BE1-87T Installation 4-7

P0066-79

Figure 4-7. M1 Case Cover Dimensions, Front View

4-8 BE1-87T Installation 9171300990 Rev V

Dielectric Test

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

• All circuits to ground: 2,121 Vdc

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

Note that this device employs decoupling capacitors to ground at all the output terminals, and at the power supply terminals (3, 4). Accordingly, a leakage current of approximately 15 milliamperes per 1000 Vac is to be expected.

Connections

Incorrect wiring may result in damage to the relay. Be sure to check the model and Style Number against the options listed in the Style Number Identification Chart (Figure 1-1) before connecting and energizing a particular relay.

NOTE

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

Except as noted above, connections should be made with a minimum wire size of 14 AWG. Figures 4-7 through 4-10 show case terminals designations for four typical relay configurations. Figures 4-11 through 4-14 show the internal connections of the BE1-87T. Control circuit connections are shown in Figures 4-15 through 4-18.

CAUTION

To prevent possible false tripping, the upper connection plug should be in place prior to removing or installing the lower connection plug.

Figure 4-8. Case Terminals: Single-Phase

9171300990 Rev V BE1-87T Installation 4-9

Figure 4-9. Case Terminals: Three-Phase, Two Input (Sensing Input Type E), Output Option E

Figure 4-10. Case Terminals: Three-Phase, Two Input (Sensing Input Type E), Output Option F

4-10 BE1-87T Installation 9171300990 Rev V

Figure 4-11. Case Terminals: Three-Phase, Three Input (Sensing Input Type G), Output Option E

9171300990 Rev V BE1-87T Installation 4-11

Figure 4-12. Internal Connections: Single-Phase, Five Input (Sensing Input Type D), Output Option E

4-12 BE1-87T Installation 9171300990 Rev V

Figure 4-13. Internal Connections: Three-Phase, Two Input (Sensing Input Type E), Output Option E

9171300990 Rev V BE1-87T Installation 4-13

EXTERNAL

CASE

GROUND

TERMINAL

PADDLE OPERATED SHORTING

BARS

POWER

SUPPLY

STATUS

INTERNAL CIRCUITRY

TARGET

1 3

2 4

UNREST

COM

REST REST

REST

D983-025

2-18-93

BE1-87T

POWER SUPPL Y

UNREST

TRIP

C2 A2 COM 1

COM2

B2 C1

TARGET

REST

TRIP

REST TRIP

REST

TRIP

Figure 4-14. Internal Connections: Three-Phase, Two Input (Sensing Input Type E), Output Option F

4-14 BE1-87T Installation 9171300990 Rev V

D983-023

2-18-93

BE1-87T

POWER

SUPPLY

STATUS

TRIP

UNREST

POWER SUPPLY

EXTERNAL

CASE

GROUND

TERMINAL

INTERNAL CIRCUITRY

PSS

COM

REST

TRIP

TARGET

UNREST

PSS

COM3

REST

PADDLE OPERATED SHORTING

BARS

C2 A2 COM 1

COM2

B2 C1

TARGET

87T

RESTRAINED

UNREST

POWER SUPPLY STATUS

D240-008

4-21-94

BE1-87T

87T

POWER

TARGET

(OPTIONAL)

TARGET

(OPTIONAL)

LEGEND:

SINGLE-PHASE: NO, NC, OR SPDT

OPTIONAL CURRENT-OPERATED

87T

TRANSFORMER DIFFERENTIAL

86 LOCKOUT RELAY

RELAY

TARGETS

AUXILIARY OUTPUT OPTION FOR

9171300990 Rev V BE1-87T Installation 4-15

Figure 4-15. Internal Connections: Three-Phase, Three Input (Sensing Input Type G), Output Option E

Figure 4-16. Control Circuits: Single-Phase, Output Option E

87T

87T 87T 87T

87T

RESTRAINED

UNREST

1 5

D240-015

4-21-94

BE1-87T

87T

POWER

TARGET

(OPTIONAL)

TARGET

(OPTIONAL)

POWER SUPPLY STATUS

LEGEND:

SINGLE-PHASE: NO, NC, OR SPDT

OPTIONAL CURRENT-OPERATED

87T

TRANSFORMER DIFFERENTIAL

86 LOCKOUT RELAY

RELAY

TARGETS

AUXILIARY OUTPUT OPTION FOR

87T

UNRESTRAINED

87T

RESTRAINED

PHASE A

87T RESTRAINED PHASE B

87T

RESTRAINED

PHASE C

87T

87T 19

87T

D329-004

3-7-91

BE1-87T

TARGET

(OPTIONAL)

TARGET

(OPTIONAL)

POWER SUPPLY STATUS

LEGEND:

87T

POWER

OPTIONAL CURRENT-

87T

TRANSFORMER

86 LOCKOUT RELAY

DIFFERENTIAL RELAY

OPERATED TARGETS

Figure 4-17. Control Circuits: Three-Phase, Two Input (Sensing Input E), Output Option E

4-16 BE1-87T Installation 9171300990 Rev V

Figure 4-18. Control Circuits: Three-Phase, Two Input (Sensing Input E), Output Option F

Figure 4-19. Control Circuits: Three-Phase, Three Input (Sensing Input G), Output E

Relay Disassembly

Precautions

The following procedures require the removal and handling of the internal printed circuit boards. Figure 419 shows the location of major components and assemblies. Because some of the components are vulnerable to electrostatic charge, the following precautions should be observed.

CAUTION

1. Always remove power from the BE1-87T by removing the connection plugs before removing or installing a printed circuit board.

2. Always neutralize static body charge before placing a printed circuit board on—or removing one from—metal surfaces. This can be accomplished by placing your hand on the metal surface before handling the boards.

3. Never pass a printed circuit board to another person whose static body charge has not been neutralized.

4. Testing or troubleshooting should always be done on a conductive and grounded (static-controlled) surface.

5. Never test printed circuit boards with an ohmmeter. The test current from the ohmmeter may exceed component ratings.

6. Printed circuit boards or integrated circuits should be transported only in electrically conductive containers. The use of ordinary plastic bags may result in damage from static charge buildup.

Circuit Board Removal Procedure

Step 1. Remove the front cover and connection plugs.

CAUTION

To prevent possible false tripping, the upper connection plug should be in place prior to removing or installing the lower connection plug.

9171300990 Rev V BE1-87T Installation 4-17

Step 2. Withdraw the cradle assembly (see Figure 4-19).

proceed unless

Relay Operating

MOTHERBOARD

FRONT PANEL

MOTHERBOARD

SINGLE-PHASE THREE-PHASE

ANALOG BOARD #1

POWER SUPPLY

ANALOG BOARD #2

ANALOG BOARD #1

ANALOG BOARD #2

UPPER SWITCH BOARD

LOWER SWITCH BOARD

UPPER SWITCH BOARD

LOWER SWITCH BOARD

D638-003

2-23-93

BE1-87T

0 A

0 B

0 C

Step 3. Remove the four screws that attach the front panel to the cradle assembly, and remove the

front panel.

Step 4. With a slight side-to-side rocking motion, withdraw Analog Board #1.

Disabling Unused Inputs

To eliminate the possibility of a spurious input from induced currents within the relay, special internal jumpers have been provided to disable any inputs that are not connected to CT wires.

Disabling unused inputs requires disassembly of the relay and must be done when the relay has been taken out of service. Access to the input-disabling jumpers requires the removal of the Analog #1 Board, shown in Figure 4-19. To avoid personal injury or equipment damage, do NOT thoroughly familiar with the instructions in sections

Precautions and Relay Disassembly: Precautions.

Figure 4-20. Side View of Cradle Assembly

CAUTION

4-18 BE1-87T Installation 9171300990 Rev V

R59 R60

OBJECTIVE JUMPER POSITION

DISABLE INPUT 3

ENABLE INPUT 3

DISABLE INPUT 5

ENABLE INPUT 5

DISABLE INPUT 4

ENABLE INPUT 4

RIGHT-HAND EDGE OF ANALOG BOARD #1

(LOOKING FROM FRONT OF RELAY.)

FOR ALL 2-INPUT RELAYS (BOTH SINGLE- AND THREE-PHASE), ALL JUMPERS MUST BE IN THE DISABLE POSITION AT ALL TIMES.

FOR OTHER RELAYS, SEE CHART BELOW .

C33

C44

AR22

AR19

AR18

AR21

CR14

CR15

C45

R48

R29

R21

R28

R54

R49

C21

C34

C18

R58

U10

J3 J2 J1

OIS

NOTE:

D641-001

9-21-94

BE1-87T

DISABLE INPUT 3

ENABLE INPUT 3

DISABLE INPUT 5

ENABLE INPUT 5

DISABLE INPUT 4

ENABLE INPUT 4

FACTORY

ADJUSTMENT

NOT FIELD

ADJUSTABLE

OBJECTIVE

JUMPER

POSITION

J2 & J5

J3 & J6

J1 & J4

J3 & J6

J2 & J5

TP1

TP2

TP3

TP4

TP7

TP8

TP9

TP10

TP11

AGND

AR5

U17

R177

TP6

-12V

R163

D1924-12

9-21-94

BE1-87T

Figure 4-21. Unused Input-Disabling Jumpers, Analog #1 Board: Option 1-0

9171300990 Rev V BE1-87T Installation 4-19

Figure 4-22. Unused Input-Disabling Jumpers, Analog #1 Board: Option 1-1

Single-Phase Units

Single-Phase Units with Option 1-0

Three Input-Disabling Jumpers are located on each Analog Board #1 as shown in Figure 4-20.

Single-Phase Units with Option 1-1

Three additional Input-Disabling Jumpers are also located on each Analog Board #1 as shown in Figure 4-21. J9 is a factory adjustment and is not intended to be changed in the field.

BE1-87T single-phase units are shipped with all inputs enabled.

Three-Phase Units

Three-Phase Units with Option 1-0

Three Input-Disabling jumpers are located on each Analog Board #1 as shown in Figure 4-20.

Three-Phase Units with Option 1-1

Three additional Input-Disabling jumpers are also located on each Analog Board #1 as shown in Figure 4-

21. J9 is a factory adjustment and is not intended to be changed in the field.

For Three-Phase Units with Input Sensing Type E (two inputs per phase)

The jumpers shown in Figures 4-20 and 4-21 are shipped in the disabled position and no further adjustment should ever be necessary.

For Three-Phase Units with Input Sensing Type G (three inputs per phase)

The jumpers shown in Figures 4-20 and 4-21 are shipped with Input 3 enabled, and Inputs 4 and 5 disabled. If only two inputs are actually used (which must be Inputs 1 and 2), it is important to disable the unused input of each phase by means of the internal Input-Disabling jumpers provided on each of the three Analog Boards #1 as shown in either Figure 4-20 or Figure 4-21. J9 in Figure 4-21 is a factory adjustment and is not intended to be changed in the field.

Sensing Connection Diagrams

Each connection diagram provides, as an example, typical transformer terminal markings, and voltage diagrams that might be found on a transformer nameplate with the winding interconnections shown. The designations for high side and low side windings are for illustrative purposes only. For example, a diagram for a delta-wye transformer is applicable to a wye-delta transformer if the winding interconnections are the same. The phase shifts shown in the voltage diagrams assume A-B-C Phase sequence (rotation).

Each connection diagram shows the CT circuit safety ground located at the switch board panel terminal block as recommended in ANSI Standard C57.13.3.

Single-Phase Input Sensing Connections

Typical single-phase input sensing connections are illustrated in Figure 4-22.

Single-phase units may also be used in three-phase configurations, one on each phase. Figure 4-23 through Figure 4-26 show several typical three-phase sensing examples using three BE1-87T singlephase relays. Many other configurations are possible.

4-20 BE1-87T Installation 9171300990 Rev V

Figure 4-23. Typical Single-Phase Sensing Connections

COM

INPUT 5

OPTIONAL

INPUTS

87T

INPUT 4

INPUT 3

INPUT 2

INPUT

D240-003

7-1-92

BE1-87T

BREAKER

C12

03-12-98

D1186-02

SWITCH BOARD

TERMINAL BLOCKS

BE1-87T-1

BE1-87T-2

BE1-87T-3

C12

Figure 4-24. Single-Phase Connections, Delta-Wye Configuration

9171300990 Rev V BE1-87T Installation 4-21

C12

04-16-99

D1186-20.vsd

SWITCH BOARD

TERMINAL BLOCKS

BE1-87T-1

BE1-87T-2

BE1-87T-3

C12

CA H

4-22 BE1-87T Installation 9171300990 Rev V

Figure 4-25. Single-Phase Connections, Wye-Wye Configuration

03-12-98

D1186-03

BE1-87T-1

(2)

(3)

(1)

BE1-87T-2

(2)

(3)

(1)

BE1-87T-3

(2)

(3)

(1)

SWICH BOARD

TERMINAL BLOCKS

Figure 4-26. Single-Phase Connections, Delta-Delta-Wye Configuration

9171300990 Rev V BE1-87T Installation 4-23

Figure 4-27. Single-Phase Connections, Delta-Wye Configuration With Two Load Busses

03-12-98

D1186-04

BE1-87T-1

(2)

(1)

(3)

BE1-87T-1

(2)

(1)

(3)

BE1-87T-1

(2)

(1)

(3)

BE1-87T B TYPE SENSING

SWITCH BOARD

TERMINAL BOARDS

Three-Phase Input Sensing Connections

Phase Shift Compensation

Three-phase units must be connected in a way that will negate any phase shift introduced by the protected power transformer. This is accomplished by one of two methods:

1. By connecting the system CTs to complement the power transformer connections (i.e., a wye/delta CT may negate the phase shift of a delta/wye power transformer, and vice versa).

2. By utilizing the internal 30° Phase Shift Compensation that is a feature of three-phase BE1-87T relays.

Advantages of Internal Phase Compensation

Three-phase units provide for internal phase angle compensation. Among the advantages of this method is the ability to connect all the CTs in wye. This not only simplifies the connections but also facilitates sharing the CTs with other devices. Furthermore, the wye connection reduces the burden on the CTs.

A set of movable jumpers (Figure 4-27) determines the direction of the compensating internal phase shift for each input. Because each jumper can be shifted +30°, –30°, or 0°; a total of 60° is achievable between two inputs for special applications. In this way, the appropriate direction of phase shift can be matched to the shift in the protected transformer. This alleviates the need for an extra set of external CTs in most applications.

Figures 4-28 through 4-34 illustrate the use of internal phase shift in lieu of matching by external CT connections. These are typical of the many combinations that can occur.

4-24 BE1-87T Installation 9171300990 Rev V

CAUTION

Assigning 30° Phase Shift Compensation requires disassembly of the relay, and must be done when the relay has been taken out of service. Access to the 30° Phase Shift jumpers requires the removal of the Analog #2 Board, shown in Figure 4-27. To avoid personal injury or equipment damage, do NOT proceed unless thoroughly familiar with the instructions in the sections on

Relay Operating Precautions and Relay Disassembly: Precautions.

30° Phase Shift Compensation Adjustment Procedure

The position of a set of movable jumpers on Analog Board #2 determines the state of the internal compensation. To gain access to these jumpers, it is necessary to remove Analog Board #2. Refer to the topic RELAY DISASSEMBLY for instructions on gaining access to the circuit board then adjust the jumpers shown in Figure 4-27 as follows:

• In cases where no phase shift is wanted, all three jumpers (φA, φB, and φC) shown in Figure 4-

27 are in the WYE-WYE position. (Relays are shipped with all jumpers in this position.)

• If one of the inputs requires a shift in phase, the jumpers for all three phases are moved as

follows:

1. The

2. The

The internal phase shift compensation is performed electronically as shown in the chart of Figure 4-27. The internal compensation can apply to any power transformer with any combination of wye, delta, or autotransformer winding connections.

A procedure to check the differential balance is described later in this section, Checking the Relay

Settings and System Inputs.

∆2 position develops A-B, B-C, C-A. ∆1 position develops A-C, B-A, C-B.

NOTE

The result of each of these vector differences has a magnitude of the square root of three times each component.

9171300990 Rev V BE1-87T Installation 4-25

Figure 4-28. 30° Phase Shift Compensation Jumpers

The transformer in the example shown in Figure 4-28 and 4-29 has a delta connection on the primary winding. The currents in each winding of the delta are A, B and C respectively as reflected from the wye connected secondary winding. The delta connection of the transformer windings causes the current flowing in the phase leads connected to the delta winding to be A-B, B-C and C-A respectively. The CT currents on the wye side must be combined similarly to provide A-B, B-C and C-A to compensate. This is done in Figure 4-28 by connecting the wye side CTs in delta such that the currents sent to the relay are A-B, B-C and C-A. This is shown in Figure 4-29 by selecting phase compensation jumper position ∆2 for the wye side input.

4-26 BE1-87T Installation 9171300990 Rev V

WYE

BE1-87T

Switch

board

terminal

blocks

Phase shift jumper

position on analog

board #2.

*An alternative to grounding one corner of the delta connected CTs is to connect the ground to a lead connected to terminal 18.

D2751-21

03-12-98

∆

WYE

BE1-87T

Switch

board

terminal

blocks

Phase shift jumper

position on analog

board #2.

D2751-22

02-05-98

Figure 4-29. Three-Phase Connections, Delta-Wye Configuration, CT Compensation

Figure 4-30. Three-Phase Connections, Delta-Wye Configuration, Internal Phase Compensation

9171300990 Rev V BE1-87T Installation 4-27

Figure 4-31. Three-Phase Connections, Wye-Delta Configuration, Internal Phase Compensation

WYE

BE1-87T

Switch

board

terminal

blocks

Phase shift jumper

position on analog

board #2.

D2751-23

03-12-98

∆

The transformer in the example shown in Figure 4-30 has a delta connection on the secondary winding. The currents in each winding of the delta are A, B and C respectively as reflected from the wye connected primary winding. The delta connection of the transformer windings causes the current flowing in the phase leads connected to the delta winding to be A-C, B-A and C-B respectively. The CT currents on the wye side must be combined similarly to provide A-C, B-A and C-B to compensate. This is shown in Figure 427 by selecting phase compensation jumper position ∆1 for the wye side input.

4-28 BE1-87T Installation 9171300990 Rev V

WYE

BE1-87T

Switch

board

terminal

blocks

D2751-24

03-12-98

WYE

Phase shift jumper position on analog

board #2.

Figure 4-32. Three-Phase Connections, Delta-Delta Configuration

9171300990 Rev V BE1-87T Installation 4-29

Switch

board

terminal

blocks

D2751-25 04-16-99

H0, X0, OR H0 X0 BUSHING, AS

APPROPRIATE

Phase shift jumper

position on analog

17 16 15 18 14 12 11 13

C B A N C B A N

BE1-87T

WYE

board #2.

(WITH UNLOADED TERTIARY)

H0 X

NOTES:

AN ALERNATIVE TO GROUNDING THE CORNER OF THE THE DELTA CONNECTED CTs IS TO CONNECT THE GROUND TO LEADS CONNECTED TO TERMINALS 13 AND18.

IF THERE IS NOT A DELTA TERTIARY, OR IF THE WYE WINDING IS UNGROUNDED, IT IS UNNECESSARY TO DELTA SHIFT THE CURRENTS FOR ZERO SEQUENCE BLOCKING.

Figure 4-33. Three-Phase Connections, Wye-Wye or Autotransformer Configuration, CT Compensation

The Wye-Wye or Autotransformer does not require phase shift compensation. However, it is necessary to Delta compensate the currents to block zero sequence currents being supplied by the transformer bank. This is shown in Figure 4-32 by connecting the CTs in Delta. In Figure 33, compensation is shown by internal phase compensation jumper setting.

4-30 BE1-87T Installation 9171300990 Rev V

Switch

board

terminal

blocks

D2751-26

03-12-98

H0, X

, OR H

X0 BUSHING,

AS APPROPRIATE

∆

1 OR

∆

BE1-87T

C B A N

*THE BE1-87T MUST USE THE SAME PHASE COMPENSATION JUMPER POSITION ON ALL INPUTS.

NOTES:

∆

1 OR

∆

Phase shift jumper position on analog

board #2.

Figure 4-34. Three-Phase Connections, Wye-Wye or Autotransformer Configuration,

Internal Phase Compensation

9171300990 Rev V BE1-87T Installation 4-31

Switch

board

terminal

blocks

D2751-27.vsd

09-07-00

16 17

∆2

BE1-87T

WYE

∆

PHASE COMPENSATION JUMPER POSITION ON ANALOG BOARD #2.

0 X0

Figure 4-35. Three-Phase Connections, Autotransformer With Loaded Delta Tertiary

The transformer in the example shown in Figure 4-34 has a delta connection on the tertiary winding. The currents in each winding of the delta are A, B, and C respectively as reflected from the wye or auto connected winding. The delta connection of the transformer windings causes the current flowing in the phase leads connected to the delta winding to be A-B, B-C and C-A respectively. The CT currents on the wye or auto windings must be combined similarly to provide A-B, B-C and C-A to compensate. This is shown in Figure 4-34 by selecting phase compensation jumper position ∆2 for these inputs. This also provides zero sequence blocking for these inputs since this transformer configuration is a source of zero sequence currents.

4-32 BE1-87T Installation 9171300990 Rev V

Setting the BE1-87T

HIGH

TERTIARY

LOW

250,000

13.2

10,935

HIGH

TERTIARY

LOW

(MVA rating of transformer) (X 1,000)

LINE- LINE

(

)

(

)

250,000

345

418

250,000

138

1,046

CT ratio

418

120

349.

935

600

22,.II

1046

240

436.

The following setting procedures include two examples:

1. Using the MVA rating of the highest-rated winding for all the other windings when making the calculations.

2. Using the top kVA rating of the transformer.

Each procedure can be used as a means to understand the principles involved, and by replacing the variables of the example, can become a procedure of general application. Variable abbreviations and definitions are provided in Table 4-1, List of Variables.

Method

Both procedures determine:

1. The matching tap and slope settings required to implement the restrained function, and

2. The unrestrained pickup setting as a multiple of the BE1-87T tap setting (i.e., the INPUT switches).

The matching tap procedure is conventional, providing tap values proportional to the normal currents as seen by the relay. An exception occurs with multiple-winding banks where zero-balance current is assumed in each pair of windings, successively.

NOTE

The dc component of the input current is effectively blocked by the gapped cores of the input CTs. Therefore, for offset fault currents or magnetic inrush, the dc component of the waveform can be ignored in fault current calculations.

Procedure One

Refer to Figure 4-35 for a one-line drawing of this example. Refer to Figure 4-34 for the three-line representation of this transformer.

Tap and Phase Shift Settings

Step 1. Determine the primary current (I

Use the MVA rating of the highest-rated winding for all the other windings when making the

calculations. (This procedure assures that the taps follow the voltage ratios. Refer to Appendix A, Setting Note 1.)

Step 2. Determine the CT secondary current (I

) of each winding:

)of each winding:

9171300990 Rev V BE1-87T Installation 4-33

Table 4-1. List of Variables

The driving input number, a procedural term designating the current input terminal whose tap is the first selected. (The setting procedure is simplified if the driving input is the input of least current, I

)

Maximum external fault current in multiples of tap (the larger of three-phase or line-ground values)

IF3

IFG

Driving input relay current used for matching in amperes

The larger of I

and IFG

Relay input current at the maximum external three-phase fault level in secondary amperes

Relay input current at the maximum external line-ground fault level in secondary amperes

The input with the least minimum current

CT primary current in amperes

Relay input current in amperes

CT secondary current in amperes

Rated self-cooled current of the power transformer in multiples of tap

Current mismatch, with power transformer on its neutral tap

Multiple rating CT, i.e., a tapped CT

Total mismatch, including the maximum transformer tap excursion

Total number of CT turns available

Number of CT turns in use

One-way lead resistance in ohms

VB3

VBG

VCE

x TA P

CT winding resistance in ohms

Relay resistance in ohms

Restrained slope setting (from 15 to 60%)

Saturation factor, which equals V

B/VCE

Relay current tap (0.4 to 1.78 for 1 A CT, 2 to 8.9 for 5 A CT)

Desired tap, based on the current ratio

The larger of V

The CT burden voltage with I

or VBG

flowing

Base accuracy class CT voltage rating

Accuracy class CT effective voltage where not all turns are used, which equals

/N)

C(NA

Unrestrained pickup setting, in multiples of tap (6 to 21)

4-34 BE1-87T Installation 9171300990 Rev V

Figure 4-36. Application Example: Autotransformer With Tertiary Winding

HIGH

TERTIARY

LOW

Position:

600/5MR

600/5T

3360 A (3 ∅) 3375 A (1 ∅)

13,280 A (3 ∅)

3000/5

2000/5MR

1200/5T

138 kV

8400 A (3 ∅) 9000 A (1 ∅)

345 kV

02-12-98

D240-004

BE1-87T

WYE (3)

(12)

13.2 kV

WYE (3)

(12)

10% LTC (11)

HIGH

SIDE

TERTIARY

LOW SIDE

Conversion

Factor

(See Figure 4-34 for 3-phase connections.)

Specifications High side Tertiary Low side

kV 345 13.2 138

MVA 200/250 40/50 200/250

CT Ratio 600/5 (MR)

600/5 (T)

3000/5 2000/5 (MR)

1200/5 (T)

CT Accuracy Class C400 C800 C400

CT Resistance (ohms) 0.3 1.5 0.6

One-Way Lead Burden (ohms) 0.7 0.7 0.7

CT Connection (Three-Phase) WYE WYE WYE

NOTE

Three-phase is the most common application of the BE1-87T. Using singlephase relays requires a Delta connection for the High side and Low side CTs (IA-IB to match the tertiary connection in the example detailed in Figure 4-34).

Step 3. Three-Phase Units Only: Adjust the phase compensation jumpers on Analog Board #2, shown in Figure 2-4 and Figure 4-27, (or use the procedure listed in Testing Three-Phase Units without Changing Jumpers, in Section 5).

Because of the grounded winding in this example, as shown in Figure 4-35 and 4-34, the high-

side, and low-side zero-sequence currents must be canceled.

∆2 position is selected to align

the High side and Low side secondary current phasors with the tertiary phasors which lead by 30° in this example:

Jumper

Step 4. Determine the relay current (I

9171300990 Rev V BE1-87T Installation 4-35

∆2

WYE

∆2

Three-Phase Units only: When using either ∆2 or ∆1 jumper positions, shown in Figure 2-4,

(INPUT 1)

(INPUT 2)

(INPUT 3)

TERTIARY

LOW

HIGH

TERTIARY

LOW

T = 2.0

T = 6.0

T = 2.5

3.49

6.04

(18.22)

18.22

(1)

4.3637.55

HIGH (INPU

T 1)

HIGH

T12

2.0

18.22

6.04

6.03

)

(

)

(

2.0

7.55

6.04

2.50

)

(()

multiply the secondary current I CTs were connected in delta. Remember that, if system CTs are connected in delta, the same square-root-of-three conversion factor must be applied.

by the conversion factor (square-root of three) just as if the

HIGH

Step 5. Determine the spread ratio of the relay currents (largest/smallest):

Spread = 18.22/6.04 = 3.0

Step 6. Determine the Driving Input (DP), which we define as the input assigned to the smallest current

in Step 4:

Step 7. Determine the Driving Input Tap (T

87T:

Choosing the 2.0 setting for the minimum inputs will yield maximum sensitivity.

Step 8. Determine the Desired Tap (T

TERTIARY

), which must be less than the 4.45 capability of the BE1-

LOW

Step 9. Select taps by rounding TD to the nearest tenth:

4-36 BE1-87T Installation 9171300990 Rev V

Step 10. Determine the CT mismatch (MN):

LOW

TERTIARY

−

)((−)

(

)−(

)

ITT

100

232

100

(the smaller of the above)

2.41-2.40

...

.40

.4%

HIGH

TERTIARY

LOW

)R3R3R(IV

RL3F3B

++=

LOW

−

(

−

)

−

IIT

100

100604

100

131

(the smaller of the above)

0.80-0.80

...

(

(the smaller of the above)

())

(

TERTIARY

−

IIT

100

(the smaller of the above)

3.02-3.0

...

())

(

())

(

(the smaller of the above)

LTC

=+=

0610106 %..

3360

120

28 A

600

,280

22 A

IF3

8400

240

35 A

3375

120

28 A

9000

240

38 A

Step 11. Determine the total mismatch (M

Add the maximum CT mismatch M

position) to the total permissible tap excursion from neutral. In this example, a change (LTC) must be accommodated. Therefore:

This procedure uses the ANSI accuracy class method. See Appendix A, Setting Note 7 for more information.

(based on the power transformer in the neutral tap

NOTE

Verify CT Performance

Step 12. Determine the maximum CT secondary fault current for external faults (I

for line-to-ground). Refer again to Figure 4-35 for this example. The maximum fault current is

recorded for each set of terminals for all combinations of external faults.

±10% load tap

for three-phase, and

Step 13. Determine the worst case burden voltage for a three-phase fault (VB3).

Where:

9171300990 Rev V BE1-87T Installation 4-37

• For wye-connected CTs:

)(

RRIV +=

33 RLFB

• For delta-connected CTs, based on a three-phase fault (refer to Appendix A, Setting Note 2):

Neglecting R

= determined in Step 12

= winding burden

, use RL from Figure 4-35:

= relay resistance in ohms (< 0.05 ohm)

= one-way lead resistance in ohms

HIGH

TERTIARY

LOW

6.19=

)7.0(22

4.15=

)7.0(353=

5.24=

( )

HIGH

TERTIARY

LOW

( )

)7.0(228=

2.39=

NONE

( )

2.53=

HIGH

TERTIARY

LOW

HIGH

TERTIARY

LOW

400

2.39

1.0=

800

4.15

02.0=

240

2.53

22.0=

(

)

(Base Accuracy)

(Number of CT Turns in Use)

Maximum Ratio

400

600

(

)

400

800

3000

(

)

800

400

1200

2000

240

(

)

)7.0(283=

Step 14. Determine the burden voltage for a line-to-ground fault (VBG).

• For wye-connected CTs:

RLFGBG RRIV += 2

Where:

= determined in Step 12

= one-way lead resistance in ohms

= relay resistance in ohms (< 0.05 ohm)

• For delta-connected CTs: V

is a function of the proportion of positive-sequence to zero-

sequence currents but may be approximated by the same equation.

Neglecting R

, use RW and RL from Figure 4-35:

)7.0(238=BGV

Step 15. Determine the effective CT accuracy class (V

Step 16. Determine the saturation factor (SF):

Note: V

is the largest burden voltage from steps 13 and 14.

4-38 BE1-87T Installation 9171300990 Rev V

Maximum recommended SF=0.5.

= =

Maximum Relay Fault Current

Corresponding Tap

3( )

HIGH

TERTIARY

LOW

7..

524.

(

)

()=

0.7

TAP

MaxE(.)

HIGH

TERTIARY

LOW

IE not maximum

X TAP = (0.7)24

= 16.8

024.

(

)

MVA

SELF

COOLED

FORCED

COOLED

(

)

(

)

Instantaneous (Unrestraint) Unit Setting

NOTE

Step 17. Determine the maximum external fault multiple (I

• For wye-connected CTs and with WYE jumpers on Analog Board #2, shown in Figure 2-

• For delta-connected CTs, or with ∆1 or ∆2 jumpers on Analog Board #2, shown in Figure

2-4, (and based on a phase-to-phase fault): (Refer to Appendix A, Setting Note 3.)

Step 18. Determine the unrestrained pickup level in multiples of tap (X TAP): Refer to Appendix A,

Setting Note 4.

NOTE

The restrained element will not operate due to the large 2nd harmonic component present in the highly distorted current.

Step 19. Using the results of Step 18, set the UNRESTRAINED PICKUP LEVEL control. Referring to

the table on the BE1-87T front panel, select the tap position (X TAP) that is higher than the result obtained in Step 18. Therefore, for this example, select SET position P (=19 X TAP) which is higher than the above result of 18.2 A.

Slope Setting

Step 20. Determine the multiples of self-cooled current (I

Where:

T = the input tap (from Step 9)

= relay current (from Step 4)

): Refer to Appendix A, Setting Note 5.

9171300990 Rev V BE1-87T Installation 4-39

MVA

SELF COOLED

and MVA

FORCED COOLED

are given in Figure 4-35.

HIGH

TERTIARY

LOW

)50)(0.6(

)40)(8.16(

)250)(5.2(

)200)(55.7(

−

(

)

604200

20250

.42

(

)()

(

)

(

)

60%

15%

MARGIN

XMFR EXCITING CURRENT

D610-010

3-2-91

BE1-87T

MAXIMUM I IN MULTIPLES OF TAP

TOTAL MISMATCH

LTI

IopI

=2.24

=2.42

Step 21. Select the restrained slope setting.

The recommended restrained slope setting (S) is a function of the total mismatch and the

power transformer exciting current. This provides an ample security margin with respect to the characteristic kneepoint of the BE1-87T. Refer to Figure 4-36.

Figure 4-37. Slope Needed to Accommodate Total Mismatch with Adequate Margin

Specifically, if the maximum saturation factor S

(from Step 16) exceeds 0.5, set the

RESTRAINED PICKUP LEVEL to setting K which is equal to 60 as shown in the table on the front panel.

For all other cases including this example, use the following equation:

Where:

S = restrained slope setting

= total mismatch in percent

= rated self-cooled current of the power transformer in multiples of tap

For a three-winding transformer application, such as this example, the maximum of the three

and of IT is used.

values of M

is 10.6 (from Step 11) and IT is 2.42 (Step 20):

4-40 BE1-87T Installation 9171300990 Rev V

)42.2(423

)36.10(35

−

+=S

= 38.8

Because the maximum saturation factor S

for this example is less than 0.5 (from Step 16), use

the next highest slope. Select position F which = 40%.

For examples of suitable slope settings, see Table 4-2.

Table 4-2. Examples of Suitable Slope Settings

Maximum

Mismatch in %

(MT)

Current Rating of Power

Transformer in

Multiples of TAP (IT)

Recommended Minimum

2.5 1.5 15

2.5 2 20

5 2 25

10 1.5 30

12.5 1.5 35

15 1.5 40

15 2 45

15 2.5 50

20 1.5 55

RESTRAINED PICKUP

LEVEL Setting* (Slope)

20 2 60

* SF=VB/VCE

>0.5, set the RESTRAINED PICKUP LEVEL setting (slope) to S=60%.

If S

9171300990 Rev V BE1-87T Installation 4-41

Procedure Two

HIGH

LOW

MVA rating

of transf

ormer

1,000

LINE- LINE

()(

)

()(

)

20,000

167.35

20,000

925

.47

Refer to Figure 4-37 for a one-line drawing of this example.

Data

Figure 4-38. Two Winding Transformer Relay Setting Calculation Example

Specifications High side Low side

kV 69 12.47

MVA 12/20 12/20

CT Ratio 600 1200

C T Tap 300 800

CT Accuracy Class 400 800

CT Resistance (ohms) 0.18 0.48

One-Way Lead Burden (ohms)

XFMR Connection*

CT Connection WYE WYE

Input # 1 2

Fault Current (ThreePhase)

Fault Current (SinglePhase)

* Standard connection: High voltage leads low voltage by 30°.

Tap and Phase Shift Settings

Step 1. Determine the full load primary current (I

0.7 0.7

D E LTA WYE

1,916 10,603

1,171 11,231

) of each winding:

Use the top kVA rating of the transformer when making the calculations:

4-42 BE1-87T Installation 9171300990 Rev V

Step 2. Determine the CT secondary current (IS):

HIGH

LOW

HIGH

LOW

Jumper Position:

WYE

HIGH

LOW

CT ratio

167.35

2.79II

925.98

160

5.79

(2.279)

(1)

.II

310..79

Step 3. Three-Phase Units Only: Adjust the phase compensation jumpers on Analog Board #2, shown

in Figure 2-4 (or use the procedure listed in TESTING THREE-PHASE UNITS WITHOUT CHANGING JUMPERS, in Section 5). Because of the grounded winding in this example, as shown in Figure 4-37, the high-side and low-side zero-sequence currents must be canceled. Because the CTs are connected in wye and the high-side currents lead the low-side currents by 30°, select the ∆2 position. This connection advances the low side phasors by 30° to match the phasors from the high-side.

∆

On single-phase units, the zero-sequence currents must be canceled by connecting the low

side CTs in delta.

Step 4. Determine the relay current (I

Three-Phase Units Only: When using either

multiply the secondary current I

x Conversion Factor

R=IS

∆1 or ∆2 jumper positions, shown in Figure 2-4,

by the conversion factor (square root of three) just as if the

CTs were connected in delta. If the system CTs are connected in delta (either three-phase or single-phase units), the same square root-of-three conversion factor must be applied.

Step 5. Determine the spread ratio of the relay currents (largest/smallest) which must be less than the

4.45 capability of the BE1-87T:

Spread = 10.02/2.79 = 3.59

If the spread exceeds 4.45, consider changing CT ratios or use auxiliary CTs.

Step 6. Determine the Driving Input (DP) which we define as the input assigned to the smallest current

in Step 4.

DP=I

DP=HIGH (INPUT 1)

9171300990 Rev V BE1-87T Installation 4-43

Step 7. Determine the Driving Input Tap (TI).

100

Current Ratio - Tap Ratio

the smaller of the above

IIT

Smaller

100

216

22 %

2.79

2.0

Smaller

100

0.2784

0.2778

100

10.02

7.2

TTI

2.0

10.02

2.79

(

)

(

)

If both relay currents are between 2.0 and 8.9 amperes, the tap settings can be set equal to the

relay currents (to the nearest 0.1 ampere). However, choosing the 2.0 tap setting for the minimum input will yield maximum sensitivity.

= 2.00

Step 8. Determine the desired Tap (T

Step 9. Select taps by rounding T

= 2.0

= 7.2

to the nearest tenth:

Step 10. Determine the CT mismatch (M

) for Input 2:

Step 11. Determine the total mismatch (M

Add the maximum CT mismatch M

position) to the total permissible tap excursion from neutral. In this example, a

= MN + LTC

(based on the power transformer in the neutral tap

±10 % load-tap

change (LTC) must be accommodated. Therefore:

=0.22 + 10 = 10.22%

4-44 BE1-87T Installation 9171300990 Rev V

Verify CT Performance

HIGH

LOW

1916

60==32 A

10603

160==66 A

1171

19.5 A

11231

160

70 A

HIGH

LOW

(32)(0.7)

22.4 V

(66)(0.7)

46.2 V

This procedure uses the ANSI accuracy class method. See Appendix A, Setting Note 7 for more information.

NOTE

Step 12. Determine the maximum CT secondary fault current for external faults at F (I

for single-phase). Refer again to Figure 4-37 for this example:

and I

Step 13. Determine the worst case CT burden voltage for a three-phase fault (VB3).

• For wye-connected CTs:

= IF3(RL + RR)

• For delta-connected CTs, for three-phase fault:

= IF3(RW + 3RL + 3RR)

Note that the wye connection produces a lower burden on the CTs (see Appendix A, Note 2).

Where:

= determined in Step 12 R

= winding burden R

= one-way lead resistance in ohms

= relay resistance in ohms (< 0.05 ohm)

for three-phase,

Neglecting R

, use RW and RL from Figure 4-37:

Step 14. Determine the worst case burden voltage for a line-to-ground fault (VBG).

• For wye-connected CTs:

= IFG(2RL + RR)

Where:

= determined in Step 12

= one-way lead resistance in ohms

= relay resistance in ohms

• For delta-connected CTs:

is a function of the proportion of positive-sequence to zero-sequence currents but may be

approximated by the same equation (for worst case).

9171300990 Rev V BE1-87T Installation 4-45

Neglecting RR, use RW and RL from Figure 4-37:

HIGH*

LOW

19.5(0.7)

13.6 V

== 70

(2(0.7))

98.0 V

HIGH

LOW

HIGH

LOW

11.0

4.22

18.0

3.533

0.98

S I

= =

Maximum Relay Fault Current

Corresponding Tap

(Base Accuracy)

(Number of CT Turns in Use)

Maximum Ratio

(

)

(400)

300

600

200

800

2000

533

(

) .

NOTE

Since a phase-to-ground fault looks like a phase-to-phase fault on the delta side of a delta/wye transformer, each CT only has to carry one times the one way lead burden.

Step 15. Determine the effective CT accuracy class (VCE):

Step 16. Determine the saturation factor (SF):

VB is the largest of the burden voltages calculated in steps 13 and 14.

=FS

200

NOTE

Maximum Recommended SF = 0.5.

Larger saturation factors will make the relay insecure for external faults. The only solution is to increase the CT quality.

Instantaneous (Unrestraint) Unit Setting

Step 17. Determine the maximum external fault multiple (I

• For wye-connected CTs and with WYE jumpers on Analog Board #2, shown in Figure 2-

4-46 BE1-87T Installation 9171300990 Rev V

• For delta-connected CTs, or with ∆1 or ∆2 jumpers on Analog Board #2, shown in Figure

(

)

HIGH

LOW

15.96

15.9

(

)

HIGH

LOW

X TAP

== (0.7)15.96

11.17

IE not maximum

()=

0.7XTAPxI

MaxE(.)

T R

MVA

SELF-COOLED

FORCED

COOLED

(

)

(

)

2-4, (and based on phase-to-phase fault): (See Setting Note 3.)

Step 18. Determine the unrestrained pickup level in multiples of tap (X TAP): (See Setting Note 4.)

This calculation assumes that the CTs carrying the maximum fault saturate severely, yielding only 30% of the expected ratio current. This leaves 70% of the fault current as a false differential current.

NOTE

The restrained element will not operate due to the large 2nd harmonic component present in the highly distorted current.

Step 19. Using the results of Step 18, set the UNRESTRAINED PICKUP LEVEL control.

Referring to the table on the BE1-87T front panel, select the tap position (X TAP) that is higher

than the result obtained in Step 18. Therefore, for this example, select SET position G (=12 X TAP) which is higher than the above result of 11.17 X TAP.

If this value exceeds 21 (max setting), raise the tap settings toward the upper end of the tap

range. If after the highest tap has been reached the unrestrained trip settings still exceeds 21, security is affected. The user should remember that the 70% saturation is conservative. A close look at the system L/R and CT performance is recommended. Chances are that the risk will be tolerable.

Slope Setting

The slope equation determines the slope setting required to maintain a margin of about 12% of I breakpoint of the slope characteristic. This margin varies slightly with the actual taps but remains secure over the tap range.

Step 20. Determine the multiples of self-cooled current (IT): Refer to Appendix A, Setting Note 5.

Where:

at the

9171300990 Rev V BE1-87T Installation 4-47

T = the input tap (from Step 9)

MVA

= relay current (from Step 4)

SELF COOLED

and MVA

FORCE COOLED

are given in Figure 4-35.

HIGH

LOW

Step 21. Select the restrained slope setting.

26.5%

35(10.2 + 3)

23 - 4(0.84)

3 +

27912

20084

()()()(

)

100212

7220084..

()(

)())(

SMI

(

)

The recommended restrained slope setting (S) is a function of the total mismatch and the

power transformer exciting current. This provides an ample security margin with respect to the characteristic kneepoint of the BE1-87T. Refer to Figure 4-36.

Specifically, if the maximum saturation factor

SF (from Step 16) exceeds 0.5, set the

RESTRAINED PICKUP LEVEL to setting K, which is equal to 60 as shown in the table on the front panel.

For all other cases, including this example, use the following equation:

Where:

S = restrained slope setting

= total mismatch in percent

= rated self-cooled current of the power transformer in multiples of tap

is 10.2 (from Step 11) and IT is 0.84 (Step 20):

Because the maximum saturation factor S

for this example is less than 0.5 (from Step 16), use

the next highest slope. Select position D, which = 30%.

For examples of suitable slope settings, see Table 4-2.

4-48 BE1-87T Installation 9171300990 Rev V

Checking the Relay Settings and System Inputs

Steps 1 and 2 check that the current inputs from the power transformer are correct and consistent with the BE1-87T settings. The remaining steps check that the relay settings are within acceptable parameters.

CAUTION

DO NOT install connection plugs, apply power, remove circuit boards, or carry

out any of the other instructions given unless you are thoroughly familiar with the instructions in the sections on Relay Operating Precautions on page 4-1 and Relay Disassembly: Precautions on page 4-11.

Step 1. Insert the cradle assembly into the relay case, then:

Three-Phase Units with Sensing Input Type G: Remove the lower connection plug first. Then

remove the upper connection plug. Insert two Test Plugs (P/N 10095 or equivalent) in place of the top and bottom connection plugs. For further information, refer to TEST PLUG in Section 6, MAINTENANCE. Terminal 20 (trip output common) shown in Figure 4-10, must be isolated for this test.

All other styles: Replace the top connection plug with a Test Plug (P/N 10095 or equivalent).

For further information, refer to TEST PLUG in Section 6, MAINTENANCE. Terminal 9 (trip output common) shown in Figures 4-7 through 4-9 must be isolated for this test.

Step 2. Using an ammeter and phase angle meter, measure the magnitude and phase angle of each

current input, testing two inputs at a time. Begin with Inputs 1 and 2.

CAUTION

When more than two inputs are present, all inputs not being tested must be shorted to ground.

Single-Phase Units: Relay must not trip when the current to each input (of the pair being

tested) is equal to the other in magnitude and the two currents are 180° out of phase (e.g., Inputs 1 and 2 measured, with Inputs 3, 4 and 5 shorted). For input terminal numbers, see Table 4-3.

Three-Phase Units: Relay must not trip when the current to Input 1 is equal to that of Input 2 in

magnitude and the phase angle is as shown in Table 4-4. If there are three inputs per phase, interchange Inputs 2 and 3 and repeat the procedure, this time with magnitudes and phase angles as shown in Table 4-4. (Testing may require six synchronized current sources.)

Step 3. Using the Test Plug, reestablish all input connections and verify that the front panel REST.

TRIP and UNREST. TRIP LEDs are extinguished.

This assures that the X TAP settings and jumper settings (refer to Figures 4-20, 4-21 and 4-27) are within acceptable parameters and that the differential current is below pickup.

If the REST. TRIP or UNREST. TRIP LEDs light, recheck the system current inputs and relay settings.

Table 4-3. Single-Phase Input Terminals

Input 1 Input 2 Input 3 Input 4 Input 5

Terminals:

9171300990 Rev V BE1-87T Installation 4-49

11 & 13 12 & 13 14 & 13 15 & 13 16 & 13

Table 4-4. Input Conditions For Non-Trip Three-Phase Sensing

240

120

180

300

240

120

(

)

150

(

)

(

)

270

240

120

(

)

210

(

)

(

)

330

240

120

(

)

210

(

)

(

)

330

240

120

(

)

150

(

)

(

)

270

30° Phase Shift

Compensation Jumper

Settings

(Ref. Figure 4-27)

WYE-WYE, ∆1-∆1, or ∆2-

∆2.

(In these cases, input currents are equal and

° out-of-phase.)

180 Input 1 is ∆1, Input 2 is

WYE.

Input 1 is WYE, Input 2 is

∆1.

Input 1 is ∆2, Input 2 is WYE.

Input 1 is WYE, Input 2 is

∆2.

NOTES:

1. Table 4-4 is for reference only and applies to three-phase units with Input 3 at zero amperes.

* For A-B-C rotation.

Input 1 *

Phase Terminals Phase Angle Terminals Phase Angle

11 & 13

12 & 13

14 & 13

11 & 13

12 & 13

14 & 13

11 & 13

12 & 13

14 & 13

11 & 13

12 & 13

14 & 13

11 & 13

12 & 13

14 & 13

15 & 18

16 & 18

17 & 18

15 & 18

16 & 18

17 & 18

15 & 18

16 & 18

17 & 18

15 & 18

16 & 18

17 & 18

15 & 18

16 & 18

17 & 18

Input 2 *

Maintenance

BE1-87T relays require no preventative maintenance other than a periodic operational check. If the relay fails to function properly, contact Technical Sales Support at Basler Electric to coordinate repairs.

Storage

This device contains long-life electrolytic capacitors. For devices that are not in service (spares in storage), the life of these capacitors can be maximized by energizing the device for 30 minutes once per year.

4-50 BE1-87T Installation 9171300990 Rev V

Test Plug

Test plugs (Basler p/n 10095) provide a quick, easy method of testing relays without removing them from their case. Test plugs are simply substituted for the connection plugs. This provides access to the external stud connections as well as to the internal circuitry.

Test plugs consist of a black and red phenolic molding with 20 electrically separated contact fingers connected to 10 coaxial binding posts. The 10 fingers on the black side are connected to the inner binding posts (black thumbnuts) and tap into the relay internal circuitry. The 10 fingers on the red side of the test plug are connected to the outer binding posts (red thumbnuts) and also connect to the relay case terminals.

When testing circuits connected to the bottom set of case terminals, the test plug is inserted with the numbers 1 through 10 facing up. When using the test plug in the upper part of the relay, the numbers 11 through 20 are face up. It is impossible, due to the construction of the test plug, to insert it with the wrong orientation.

9171300990 Rev V BE1-87T Installation 4-51

4-52 BE1-87T Installation 9171300990 Rev V

SECTION 5 • TEST PROCEDURES

TABLE OF CONTENTS

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

Overview ................................................................................................................................................ 5-1

Equipment Required .............................................................................................................................. 5-1

Restrained Pickup Testing Examples .................................................................................................... 5-2

Increasing One Input from Balance .................................................................................................... 5-2

Decreasing One Input from Balance .................................................................................................. 5-4

Test Setup Diagrams ............................................................................................................................. 5-7

Verification Tests: 5 Amp CT, 50 or 60 Hz Units ................................................................................... 5-9

Restrained Pickup Verification ........................................................................................................... 5-9

Input (or Tap) Switch Verification ..................................................................................................... 5-10

Unrestrained Pickup Verification ...................................................................................................... 5-11

Second-Harmonic Restraint Verification .......................................................................................... 5-11

Fifth-Harmonic Restraint Verification ............................................................................................... 5-12

Response Time Verification ............................................................................................................. 5-13

Verification Tests: 1 Amp CT, 50 or 60 Hz Units ................................................................................. 5-14

Restrained Pickup Verification ......................................................................................................... 5-14

Input (or Tap) Switch Verification ..................................................................................................... 5-15

Unrestrained Pickup Verification ...................................................................................................... 5-16

Second-Harmonic Restraint Verification .......................................................................................... 5-17

Fifth-Harmonic Restraint Verification ............................................................................................... 5-17

Response Time Verification ............................................................................................................. 5-18

Operational Test Procedures ............................................................................................................... 5-19

Restrained Pickup ............................................................................................................................ 5-19

Unrestrained Pickup ......................................................................................................................... 5-19

Second-Harmonic Inhibit .................................................................................................................. 5-19

Fifth-Harmonic Inhibit ....................................................................................................................... 5-20

Testing Three-Phase Units without Changing Jumpers ...................................................................... 5-20

Jumper Positions WYE-WYE ........................................................................................................... 5-21

Jumper Positions WYE-∆1 ............................................................................................................... 5-21

Jumper Positions WYE-∆2 ............................................................................................................... 5-22

Jumper Positions ∆1-∆1 ................................................................................................................... 5-22

Jumper Positions ∆2-∆2 ................................................................................................................... 5-23

Jumper Positions ∆1-∆2 ................................................................................................................... 5-23

Figures

Figure 5-1. Test Setup: Single-Phase ....................................................................................................... 5-7

Figure 5-2. Test Setup: Three-Phase, Sensing Input Type E, Output Option E ....................................... 5-7

Figure 5-3. Test Setup: Three-Phase, Sensing Input Type E, Output Option F ....................................... 5-8

Figure 5-4. Test Setup: Three-Phase, Sensing Input Type G, Output Option E ....................................... 5-8

Tables

Table 5-1. Restrained Pickup Test: 5 A, 50 or 60 Hz .............................................................................. 5-10

Table 5-2. Input Verification*: 5 A, 50 or 60 Hz Table 5-3. Unrestrained Pickup Verification: 5 A, 50 or 60 Hz Table 5-4. Timing: 5 A, 50 or 60 Hz Table 5-5. Restraint Pickup Test: 1 A, 50 or 60 Hz Table 5-6. Input Verification*: 1 A, 50 or 60 Hz Table 5-7. Unrestrained Pickup Verification, 1 A, 50 or 60 Hz Table 5-8. Timing, 1 A, 50 or 60 Hz Table 5-9. Input Signals to Comparison Circuits Based On Jumper Positions

9171300990 Rev V BE1-87T Test Procedures i

....................................................................................... 5-11

................................................................ 5-11

......................................................................................................... 5-13

................................................................................. 5-15

....................................................................................... 5-16

................................................................ 5-16

......................................................................................................... 5-18

....................................... 5-21

ii BE1-87T Test Procedures 9171300990 Rev V

SECTION 5 • TEST PROCEDURES

Overview

BE1-87T Transformer Differential Relays are calibrated and tested for correct operation at the factory and all calibration pots are sealed.

Immediately upon receipt of the relay, or after extended service, it is recommended that the Verification Tests provided in this section be performed. These comprehensive tests verify all operating parameters including calibration.

BE1-87T relay Verification Tests are divided into two groups based on the current CT ampere rating and the nominal operating frequency: (See the first position of the Style Number and the Sensing Input Range Option as shown in Figure 1-1.)

Five Amperes CT, 60 Hz Units (Range 1) and Five Amperes CT, 50 Hz Units (Range 3)

One Ampere CT, 60 Hz Units (Range 4) and One Ampere CT, 50 Hz Units (Range 2)

Within each group are separate tests that can be performed individually to make it easier to focus on a particular problem. However, all of these tests should be performed prior to putting the relay into service.

To help field users understand the verification procedures, four examples for restrained pickup testing are provided before the actual Verification Tests begin. Two examples are for increasing one input from balance and two examples are for decreasing one input from balance. These examples are not a necessary part of verification testing, but are provided for clarification.

For routine assurance that the BE1-87T is operating correctly, the simplified OPERATIONAL TESTS may be performed.

Before starting a test program, check the Style Number of the relay against the Style Number Identification Chart, Figure 1-1, to identify the specific features and options to be tested. For location of the switches and controls, refer to Figures 2-1 and 2-2 for Input Range 1 or 3, and Figures 2-3 and 2-4 for Input Range 2 or 4.

NOTE

LEDs and targets (if provided) should be checked for proper operation and targets reset after they have been tripped. Current-operated (Type D) targets will only operate when a minimum of 0.2 A is present in the trip circuit.

Similarly, the auxiliary contacts (if present) should be checked for proper operation. Switches S1 and S2, located on the mother board and shown in Figure 2-4 allow the auxiliary output to operate in conjunction with a restrained trip, an unrestrained trip, or both.

Equipment Required

The following test equipment (or equivalent) is required for either the Operational Tests or the Verification Tests:

1. Two current sources with independently regulated current outputs. Must be able to produce outputs 180° out of phase. If harmonic testing is desired, harmonic capability is also required.

2. Counter, 0 to 0.5 second range.

3. Two Test Plugs, Basler p/n 10095 (see Test Plug in Section 4, Installation).

4. Phase angle meter or oscilloscope with an ungrounded plug or ground isolation transformer.

9171300990 Rev V BE1-87T Test Procedures 5-1

Restrained Pickup Testing Examples

ITI

112

−

I I

Amps

1 2

0 35

slope

0 35

100

 



 



−

 



 



sTT

trip1

2 1

min

−

I T

trip1 1

0 35

min

.= +

 



 



unbalance >

(maximum restraint)

or 0.35 pu, whichever is greater

slope

100

slope

trip min

balance

(100)

(in pu)

balance

slope

100

(

)

(in pu)

(

)

trip min

balance

0.35 (

in pu)

Increasing One Input from Balance

The formula to determine the unbalance value at which the restrained trip occurs is:

Where:

unbalance = absolute value of (I

slope = the RESTRAINED PICKUP LEVEL setting (15 to 60)

maximum restraint = larger of I

By increasing the I

1) When:

input current from balance: (The balance current is

balance1

This means the pu restraint current is to the right of the intersection of the slope characteristic with the

0.35 MPU horizontal line (see Figure 1-2).

the minimum trip point is established as:

- I2) in per unit (pu) i.e.

or I2 in pu i.e.

 



 



slope

 





−

 

100

slope

100

(in pu)

2) When:

the minimum trip point is established as:

5-2 BE1-87T Test Procedures 9171300990 Rev V

(in Amps)

(Equation 1)

(Equation 1a)

(Equation 2)

(Equation 2a)

Example One:

tap tap slope

1 2

2 3 8 15%= = =, . ,

trip1

3 8

0 35

2 7

= +

 



 



. A

tap tap slope

1 2

2 3 8 15%= = =, . ,

Inputs I A pu

I A pu

: ( )

. ( )

6 3

11 4 3

11 4

3 8

= = =

 



 



= = =

 



 



balance

slope

0.35

100

−

(in pu)

1.983

(

)

(

)

1<>

0.35

0.15

1 - 0.15

(

)

trip

1 pu+0.35

1.35 pu

tap

trip

1.35 pu

(1.35)

100 mA

Assume:

Inputs I A pu

: ( )

2 1

= = =

I A pu

. ( )

38 1

= = =

Check:

Therefore: Use Equation 2 or 2a.

From Figure 1-2 (the percentage restraint characteristic of the BE1-87T at 15% slope), the minimum current where trip occurs is:

 



 





 



 

In terms of current, the trip current is:

Using Equation 2a:

Example Two:

Assume:

9171300990 Rev V BE1-87T Test Procedures 5-3

Check:

trip1

11 4

1 0 1523 8 7 06

min

. .

−

= A

I I

2 1

= ×

slope

balance2

0 35

100

 



 



(in pu)

slope

0 35

100

 



 



balance

slope

0.35

100

(in pu)

1.983

(

)

(

)

3<>

0.35

0.15

1 - (0.15)

)

(

trip

3 pu

3.53 pu

trip

3.53 pu

tap

(3.53) (2

.0)

7.06 A

100 mA

unbalance

(maximum restraint)

or 0.35 pu, whichever is greater

slope

100

slope

trip

balance

100

)

(in pu)

(

Therefore: Use Equation 1 or 1a.

From Figure 1-2 (the percentage restraint characteristic of the BE1-87T at 15% slope), the minimum current where trip occurs is:

In terms of current, the trip current is:

Using Equation 1a:

Decreasing One Input from Balance

The formula to determine the unbalance value at which the restrained trip occurs is:

Where:

unbalance - absolute value of I

slope = the RESTRAINED PICKUP LEVEL setting (15 to 60)

maximum restraint = larger of I

By decreasing the I

input current from balance:

- I2 in per unit (pu)

or I2 in pu =I

The balance current is

1) When:

the value of I

5-4 BE1-87T Test Procedures 9171300990 Rev V

is defined as:

2 trip max.

(Equation 3)

Basler Electric BE1-87T User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

INTRODUCTION

REVISION HISTORY

CONTENTS

SECTION 1 • GENERAL INFORMATION

Introduction

Description

Application

Single-Phase

Three-Phase

Percentage Restraint

Second-Harmonic Restraint

Fifth-Harmonic Restraint

Unrestrained Trip

Options

Push-To-Energize Output Pushbuttons

Auxiliary Output Contacts

Power Supply

Model and Style Number

Style Number Example

Specifications

SECTION 2 • CONTROLS AND INDICATORS

Location of Controls and Indicators

SECTION 3 • FUNCTIONAL DESCRIPTION

General

Description

Current Transformers

Scaling

Summing

30° Internal Phase Shift (Three-Phase Relays ONLY)

Restrained Trip Output

Percentage Restraint

Harmonic Restraints

Unrestrained Trip Output

Auxiliary Relay Option

Power Supply

Power Supply Status Output (Optional)

Target Indicators (Optional)

% of Trip

SECTION 4 • INSTALLATION

General

Relay Operating Precautions

Mounting

Dielectric Test

Connections

Relay Disassembly

Precautions

Circuit Board Removal Procedure

Disabling Unused Inputs

Single-Phase Units

Single-Phase Units with Option 1-0

Single-Phase Units with Option 1-1

Three-Phase Units

Three-Phase Units with Option 1-0

Three-Phase Units with Option 1-1

For Three-Phase Units with Input Sensing Type E (two inputs per phase)

For Three-Phase Units with Input Sensing Type G (three inputs per phase)

Sensing Connection Diagrams

Single-Phase Input Sensing Connections

Three-Phase Input Sensing Connections

Phase Shift Compensation

Advantages of Internal Phase Compensation

30° Phase Shift Compensation Adjustment Procedure

Setting the BE1-87T

Method

Procedure One

Tap and Phase Shift Settings

(See Figure 4-34 for 3-phase connections.)

Verify CT Performance

Instantaneous (Unrestraint) Unit Setting

Slope Setting

Procedure Two

Data

Tap and Phase Shift Settings

Verify CT Performance

Instantaneous (Unrestraint) Unit Setting

Slope Setting