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BE1-51/27C
User Manual
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Basler Electric BE1-51/27C User Manual

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INSTRUCTION MANUA L
FOR

BE1-51/27C

Time Overcurrent Relay with Voltage Control
Publication: 9137200998 Revision: E Mar-15
Caution
Note

Preface

This instruction manual provides information about the installation and operation of the BE1-51/27C Time Overcurrent Relay with Voltage Control. To accomplish this, the following information is provided:
• General information
• Controls and indicators
• Functional description
• Installation
• Tests and adjustments
• Specifications
Conventions Used in this Ma nua l
Important safety and procedural information is emphasized and presented in this manual through warning, caution, and note boxes. Each type is illustrated and defined as follows.
Warning!
Warning boxes call attention to conditions or actions that may cause personal injury or death.
Caution boxes call attention to operating conditions that may lead to equipment or property damage.
Note boxes emphasize important information pertaining to installation or operation.
Basler Electric does not assume any responsibility to compliance or noncompliance with national code, local code, 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.
This publication contains confidential information of Basler Electric Company, an Illinois corporation. It is loaned for
manual.
The English-language versi on of this manu al ser ves as the only appr ove d manual version.
12570 State Route 143
Highland IL 62249-1074 USA
www.basler.com
info@basler.com
Tel: +1 618.654.2341
Fax: +1 618.654.2351
© 2015 by Basler Electric
All rights reserved
First printing: September 1993
Warning!
READ THIS MANUAL. Read this manual before installing, operating, or maintaining the BE1-51/27C.
Note all warnings, cautions, and notes in this manual as well as on the product. Keep this manual with the product for reference. Only qualified personnel should install, operate, or service this system. Failure to follow warning and cautionary labels may result in personal injury or property damage. Exercise caution at all times.
or any other applicable code. This manual serves as reference material that must be well understood prior to installation, operation, or maintenance.
confidential use, subject to return on request, and with the mutual understanding that it will not be used in any manner detrimental to the interests of Basler Electric Company and used strictly for the purpose intended.
It is not the intention of this manual to cover all detai ls and var iatio ns in equi pm ent, 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. Over time, improvements and revisions may be made to this publication. Before performing any of the following procedures, contact Basler Electric for the latest revision of this

Contents

Introduction ................................................................................................................................................. 1
Standard Features ..................................................................................................................................... 1
Time Overcurrent Functions .................................................................................................................. 1
Non-Integrating Timing .......................................................................................................................... 2
Integrating Timing .................................................................................................................................. 3
Built-In Test ............................................................................................................................................ 3
Options ...................................................................................................................................................... 3
Timing .................................................................................................................................................... 3
Sensing Input Type ................................................................................................................................ 3
Sensing Input Range ............................................................................................................................. 3
Power Supply ......................................................................................................................................... 3
Targets ................................................................................................................................................... 4
Outputs .................................................................................................................................................. 4
Instantaneous Outputs ........................................................................................................................... 4
Packaging .............................................................................................................................................. 4
Model and Style Number Description ........................................................................................................ 4
Controls and Indicators .............................................................................................................................. 7
Functional Description ............................................................................................................................. 11
Block Diagram Analysis ........................................................................................................................... 11
Power Supply ....................................................................................................................................... 12
Current Sensing ................................................................................................................................... 12
Tap Select and Tap Cal ....................................................................................................................... 12
Voltage Sensing ................................................................................................................................... 12
Multiplexor ............................................................................................................................................ 12
Analog-To-Digital Converter and Level Detector ................................................................................. 12
Time Trip Comparator and Scaler ....................................................................................................... 12
Microprocessor (Not Shown) ............................................................................................................... 13
Voltage Inhibit ...................................................................................................................................... 13
Instantaneous Overcurrent (Options 1-1 and 1-2) ............................................................................... 13
Timed and Instantaneous Outputs....................................................................................................... 13
Auxiliary Outputs .................................................................................................................................. 13
Push-to-Energize Pushb utt ons ............................................................................................................ 13
Power Supply Status Output (Option 3-6) ........................................................................................... 13
Target Indicators .................................................................................................................................. 14
Installation ................................................................................................................................................. 15
Relay Operating Guidelines and Precautions ......................................................................................... 15
Mounting .................................................................................................................................................. 15
Connections ............................................................................................................................................. 28
Maintenance ............................................................................................................................................ 39
Storage .................................................................................................................................................... 39
Tests and Adjustments ............................................................................................................................. 41
Required Test Equipment ........................................................................................................................ 41
Operational Test ...................................................................................................................................... 41
Preliminary Instructions ....................................................................................................................... 41
Time Overcurrent Pickup Test ............................................................................................................. 45
Timed Output Test ............................................................................................................................... 47
Instantaneous Overcurrent Pickup Test .............................................................................................. 49
Voltage Control Test ............................................................................................................................ 50
Adjustments of Controls for Relay Operation .......................................................................................... 51
TAP and TAP (NEUTRAL) Selector Setting ........................................................................................ 51
Time Overcurrent Curve Selection (Timing Type Z1, Z2, and Z3 Only) .............................................. 53
Time Delay Selection ........................................................................................................................... 53
Neutral Time Delay Selection .............................................................................................................. 54
VOLTS INHIBIT ADJ or VO LT AGE I NH I BIT ADJ Se tti n g ................................................................... 54
INST 1 Control Setting ......................................................................................................................... 54
INST 2 Control Setting ......................................................................................................................... 55
Setting the Relay ..................................................................................................................................... 55
General ................................................................................................................................................ 55
Setting Example ................................................................................................................................... 56
Coordination with Feeder 51 Relay for Fault 1 .................................................................................... 57
Checking Coordination with Relay 67 for Fault 2 ................................................................................ 58
Checking Coordination with Relay 67 for Fault 3 ................................................................................ 59
Neutral Element Backup Settings ........................................................................................................ 60
Specifications ............................................................................................................................................ 61
Operational Specifications ....................................................................................................................... 61
Time Overcurrent Pickup Selection Range ......................................................................................... 61
Time Overcurrent Measuring Accuracy ............................................................................................... 61
Time Overcurrent Dropout Rati o .......................................................................................................... 61
Instantaneous Overcurrent Pickup Range ........................................................................................... 61
Instantaneous Overcur rent Meas ur ing Ac c urac y ................................................................................ 61
Instantaneous Overcurrent Dropout Ratio ........................................................................................... 61
Instantaneous Response ..................................................................................................................... 61
Time Delay Accuracy ........................................................................................................................... 62
General Specifications............................................................................................................................. 62
Voltage Sensing Inputs ........................................................................................................................ 62
Voltage Sensing Selection Rang e ....................................................................................................... 62
Voltage Sensing Accuracy ................................................................................................................... 62
Sensing Input Burden .......................................................................................................................... 62
Sensing Input Rating ........................................................................................................................... 62
Output Circuits ..................................................................................................................................... 62
Target Indicators .................................................................................................................................. 62
Power Supply ....................................................................................................................................... 62
Radio Frequency Interference (RFI) .................................................................................................... 63
Isolation ................................................................................................................................................ 63
Surge Withstand Capability ................................................................................................................. 63
UL Recognized .................................................................................................................................... 63
GOST-R ............................................................................................................................................... 63
Operating Temperature ....................................................................................................................... 63
Storage Temperature ........................................................................................................................... 63
Shock ................................................................................................................................................... 63
Vibration ............................................................................................................................................... 64
Weight .................................................................................................................................................. 64
Case Size ............................................................................................................................................. 64
Time Overcurrent Characteristic Curves ................................................................................................ 65
Revision History ...................................................................................................................................... 103
9137200998 Rev E 1

Introduction

BE1-51/27C Time Overcurrent Relays are microprocessor-based devices that monitor the magnitude of line current to provide accurate time-overcurrent protection with undervoltage control (when the voltage drops below the set point, the timing circuit is enabled). Instantaneous overcurrent element(s) and the neutral time overcurrent element, when supplied, operate independently of the undervoltage function. Each relay is available with one, three, or four time overcurrent elements.
BE1-51/27C relays provide backup protection for generators or transformers. Voltage control provides discrimination between load and fault conditions by allowing the time overcurrent pickup to be set below the maximum load (or swing) current. For sustained fault conditions, the synchronous reactance, X typically larger than for normal load, X fault current will be less than the normal maximum load current. The relay pickup should be set below rated maximum load current (e.g., 50 percent of rated) to ensure dependable backup. The BE1-51/27C relay may also be used to provide primary phase fault protection for small generators or backup protection for transformers.
When the BE1-51/27C is used to protect for faults on either side of a delta-wye power transformer, phase overcurrent units should be supplied on all three phases (either three single-phase relays or one three­phase relay). For this application, each phase time overcurrent element should be controlled by the phase-to-ground voltage on its phase rather than by the phase-phase voltage.
Because the time overcurrent pickup of the phase element(s) does not vary with voltage level (the element is either enabled or not depending upon voltage level), conventional time coordination techniques apply.
. As a result, if the regulator is not in service, the three-phase
d(sat)
d(unsat)
, is
A neutral (ground) overcurrent element can be applied and connected residually to a set of three current transformers on solidly grounded applications or on impedance grounded systems that provide ground fault current approximating the generator rated current level. The neutral element can also be connected to a 10:1 ampere, zero-sequence window current transformer to provide protection on systems producing a minimum of about 20 amperes primary current. Still another alternative would be connecting this device to a current transformer in the neutral of a generator or power transformer.
Instantaneous elements can be used for transformer back-up applications when connected on the source side of the power transformer. Because the pickup of these elements can be set above the relay current flowing in the low-side fault, coordination can be achieved. Instantaneous overcurrent elements would not ordinarily be used for a generator back-up function because they would not operate correctly for faults external to the generator zone.
Under normal operating conditions, the phase time overcurrent pickup will be less than the maximum load or non-fault current. As long as the rated voltage is applied to the relay, no operation will occur. However, if a fuse opens on the voltage transformer and interrupts the signal, the relay will see this as a fault condition (i.e., current level above pickup and voltage level below minimum set point) and operate accordingly. The Basler Electric BE1-60 Voltage Balance Relay can prevent such a misoperation where two sources of signal voltage are available. This relay compares the output of two signal sources, to detect an anomaly in one of these sources and block the operation of those devices connected to that signal source. Therefore, for generator applications, the Basler BE1-60 Voltage Balance relay should be used in conjunction with the BE1-51/27C to prevent misoperations due to loss of the voltage source.

Standard Features

Time Overcurrent Functions

Time overcurrent elements pick up over a range of 0.1 to 0.8 amperes, 0.3 to 2.4 amperes, 0.5 to 4.0 amperes, 1.5 to 12.0 amperes, 0.1 to 2.4 amperes, or 0.5 to 12.0 amperes and provide an adjustable time delay that is proportional to the overcurrent. Time delay is initiated when the sensed current exceeds the pickup point. When the current drops below the pickup point, the timing circuit is reset immediately. At reset, the output contacts, if operated, are restored to normal.
Adjustment of the overcurrent pickup point is provided by controls on the relay front panel. Time delay is a function of the characteristic curve that has been selected. Time delay is settable from 00 to 99 on the TIME DIAL thumbwheel switch located on the front panel. Curve type is selected either as an option or, in some models, is switch selectable.
Sixty-nine characteristic curves and three timing options are available: Characteristic curves:
• Seven inverse time
• Nine I
• Seven inverse time with extended timing range
• Nine I
2
t
2
t with extended timing range
• Five British Standard 142 (E curves)
• Seven integrating inverse time
• Nine integrating I
• Seven integrating inverse time with extended timing range
• Nine integrating I
2
t
2
t with extended timing range
Timing option Z1 (switch-selectable, 16-position) B and C curves:
• Seven inverse time
• Nine I
2
t
Timing option Z1 with option 2-D or 2-E (switch-selectable, 16-position) B and C curves:
• Seven inverse time with extended timing range
• Nine I
2
t with extended timing range
Timing option Z2 (switch-selectable, 16-position) B and E (British Standard 142) curves:
• Seven inverse time
• One I
2
t
• Five British Standard (BS) 142 (E curves)
Timing option Z2 with option 2-D or 2-E (switch-selectable, 16-position) B and E (BS142) curves:
• Seven inverse time with extended timing range
• One I
2
t with extended timing range
• Five British Standard 142 (E curves)
Timing option Z3 (switch-selectable, 16-position) integrating B and C curves:
• Seven integrating inverse time
• Nine integrating I
2
t
Timing option Z3 with option 2-D or 2-E (switch-selectable, 16-posit ion) int egr at in g exten ded B and C
curves:
• Seven integrating inverse time with extended timing range
• Nine integrating I
2
t with extended timing range
Characteristic curves are shown by the graphs in the Time Overcurrent Characteristic Curves chapter. Note that each graph (i.e. function) consists of a set of representative curves. Each curve (as well as any between-curve interpolation) is selectable by the front panel TIME DIAL using a two-digit destination from 00 to 99. Because of space limitations, each graph shows only 14 of the 100 possible selections.

Non-Integrating Timing

Timing options Z1 and Z2 and the characteristic curves available with those options use non-integrating timing. Non-integrat ing timi ng is acc ompl ished by timing at a gate that is not solely dependent on the magnitude of the applied multiple of pickup current. The time-out value is calculated based on the type of time curve characteristic selected, time dial setting, and the magnitude of the applied multiple of pickup current. The time-out value is continuously updated during the timing cycle. When pickup is exceeded, a timer is initiated. When the timer elapsed time exceeds the calculated time-out value, a time trip output signal is generated.
9137200998 Rev E 3
This type of non-integrating time delay characteristic exhibits a dynamic characteristic that is immediately responsive to changes of the applied multiple of pickup current.

Integrating Timing

Timing option Z3 and the characteristic curves available for that option uses integrating timing. Integrating timing is accomplished by summing time increments that are based on the magnitude of the applied multiple of pickup current, the time curve characteristic selected, and the time dial value. These time increments are summed until a predetermined value is exceeded, then a time trip output signal is generated.
This type of integrating time delay characteristic simulates the operating characteristics of an electromechanical overcurrent relay.

Built-In Test

A built-in test (BIT) switch mounted on the Logic Board provides diagnostic troubleshooting and calibration.

Options

Timing

An extended timing option multiplies by approximately 5.7, the standard time delays. The resulting curves are shown following the standard curves in the Time Overcurrent Characteristic Curves chapter.
When timing option Z1, Z2, or Z3 is specified, a printed circuit board mounted selector switch allows a choice of up to sixteen different time overcurrent functions. Timing option Z1 or Z3 may be further specified as standard or extended time, depending upon option 2 selection.

Sensing Input Type

When single-phase, two-phase-and-neutral, three-phase, or three-phase-and-neutral sensing has been specified, the front panel TAP selector and the front panel TAP CAL control set the pickup point for all phases. An independent front panel TAP (NEUTRAL) selector and front panel CAL (NEUTRAL) control set the neutral pickup point. In addition, for three-phase-and-neutral sensing units, one of the seven sensing input range combinations must be specified.
Relay circuits inhibit the phase-element time overcurrent operation for a specific phase if the monitored ac voltage exceeds a preselected level. The voltage level is established by a front panel VOLTS ADJ control and all phases are inhibited at the same voltage level. Neutral overcurrent elements are not inhibited. When the voltage inhibit level is exceeded, front panel INHIBIT LED is lit for the affected phase and the front panel TIMING LED f or that particular phase extinguishes.

Sensing Input Range

For three-phase-and-neutral sensing units, input ranges are:
• 0.5 to 4.0 amperes (phas e and neutra l)
• 1.5 to 12 amperes (phase) and 0.5 to 4.0 amperes (neutral)
• 0.5 to 4 amperes (phase) and 1.5 to 12 amperes (neutral)
• 1.5 to 12 amperes (phase and neutral)
• 0.1 to 0.8 amperes (phase and neutral)
• 0.3 to 2.4 amperes (phase) and 0.1 to 0.8 amperes (neutral)
• 0.3 to 2.4 amperes (phase and neutral)
For all other units, two ranges are available: 0.5 to 12 amperes and 0.1 to 2.4 amperes.

Power Supply

Five power supply options are available:
• 24 Vdc
• 48 Vdc
• 125 Vdc and 100/125 Vac
• 48 Vdc or 125 Vdc and 100/125 Vac
• 250 Vdc and 240 Vac

Targets

Single-phase relays have two function targets that indicate when the time delay or instantaneous element(s) have operated. On multiple phase relays, additional targets indicate which phase or neutral element(s) operated.
Function targets may be specified as either internally operated or current operated by a minimum of 0.2 amperes through the output trip circuit. When current operated, the output circuit must be limited to 30 amperes for 0.2 seconds, 7 amperes for 2 minutes, and 3 amperes continuously.

Outputs

Optional normally opened, normally closed, or SPDT auxiliary output contacts may be selected. Contacts actuate when the output relay is energized. Internally operated front panel mounted targets, and front panel targets operated by the dc current in the output circuit are available for the time overcurrent and instantaneous overcurrent functions. Optional front panel mounted PUSH-TO-ENERGIZE-OUTPUT pushbuttons allow direct actuation of each output relay for external circuit testing.

Instantaneous Outputs

One or two instantaneous overcurrent outputs are optionally available. Each is adjustable up to 40 times the time overcurrent pickup point. When the sensed current exceeds the instantaneous overcurrent pickup point, an output relay is energized. An independent front panel control (INST 1 or INST 2) adjusts the pickup point for each optional output. If more than one phase is applied to the relay, the instantaneous pickup point will be the same for all phases. If neutral current is sensed, a front panel INST 1 (NEUTRAL) provides adjustment of the neutral pickup point. Instantaneous overcurrent elements are not voltage controlled.

Packaging

Each relay is mounted in a drawout cradle and enclosed in a standard utility style case with either semi­flush or projection mounting (depending upon case style selected). An available test plug (Basler Electric part number 10095) allows the relay to be tested in place without disturbing external control circuit wiring.

Model and Style Number Description

Electrical characteristics and operational features included in a particular style of the BE1-51/27C Time Overcurrent Relay are defined by a combination of letters and numbers that make up its style number. The model number, together with the style number, describes the options included in a specific device, and appears 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.
The Style Number Identification Chart (Figure 1) illustrates the manner in which the relay style number is determined. For example, if the style number were T3E-Z1P-B1C1F, the device would have the following characteristics:
T - Three-Phase-and-Neutral sensing, 3-phas e, 4-wire voltage control 3 - Sensing input range of 1.5 to 12.0 amperes for phase and 0.5 to 4.0 amperes for neutral E - Normally open outputs Z1 - Switch selectable time curves P - Operating power derived from 125 Vdc or 120 Vac B - Current operated targets
9137200998 Rev E 5
1 - One instantaneous element C - Push-to-energize outputs 1 - Normally open auxiliary timed output relay F - Semi-flush mounting
Figure 1. Style Number Identification Chart
9137200998 Rev E 7

Controls and Indicators

BE1-51/27C controls and indicators are located on the front panel and left-side interior. The controls and indicators are shown in Figure 2 and described in Table 1. Your relay may not have all of the controls and indicators shown and described here.
Figure 2. Location of Controls and Indicators
Table 1. Controls and Indicators
A Phase Tap Calibration Control. This single-turn potentiometer adjusts the phase overcurrent pickup
threshold between the selected phase tap setting and the next lower tap setting.
B Phase Tap Selector. Selects the phase overcurrent pickup point in conjunction with the front panel
Phase Tap Calibration Control (locator A).
C Phase Instantaneous 1 Control. This four-turn potentiometer adjusts the phase instantaneous 1
element trip setting over the range of 1 to 40 times the selected Phase Tap Selector (locator B) setting value. Your relay may be equipped with a Phase Instantaneous 2 Control which provides similar adjustment of the phase instantaneous 2 element trip setting.
D Phase Time Dial Selector. These two knobs set the time delay between sensing of a phase
overcurrent condition and closing of the output contacts. See the Time Overcurrent Characteristic Curves chapter for curve selection information.
E Target Indicators. LED indicators latch on when the corresponding output relay is energized by an
overcurrent condition. Target indicators are reset by the Target Reset Switch (locator H).
F Push-to-Energize Output Pushbuttons. These recessed pushbuttons are depressed to energize the
external trip circuits for testing purposes. A thin, non-conducting rod should be used to depress the buttons. Do not use a screwdriver.
G Tap Selector Table. This front-panel reference lists the high and low setting limits for a particular tap
selection. H Target Reset Switch. Operating this switch resets all active targets (locator E). I Power Ind ic ator. This LED indicator lights when control power is applied and the relay power supply is
functioning. J Timing Indicators. A Timing LED lights when the corresponding overcurrent pickup point is reached
and exceeded. K Neutral Time Dial Selector. These two knobs set the time delay between sensing of a neutral
overcurrent condition and closing of the output contacts. See the Time Overcurrent Characteristic
Curves chapter for curve selection information. L Neutral Tap Calibration Control. This single-turn pote n tiom eter adjus ts the phase ov erc urr ent pickup
threshold between the selected neutral tap setting and the next lower tap setting. M Neutral Tap Selector. Selects the neutral overcurrent pickup point in conjunction with the front panel
Neutral Tap Calibration Control (locator L). N Neutral Instantaneous 1 Control. This four-turn potentiometer adjusts the neutral instantaneous 1
element trip setting over the range of 1 to 40 times the selected Neutral Tap Selector (locator M)
setting value. O Voltage Inhibit Indicators. A Voltage Inhibit indicator lights when the sensed input voltage level
exceeds the Voltage Inhibit control setting (locator P). P Voltage Inhibit Control. This four-turn potentiometer adjusts the voltage inhibit level over the range of
40 to 120 Vac.
The time overcurrent characteristic curve selector (not shown) is located on the left-side interior. This circuit board mounted switch selects the characteristic curve to be used.
Prior to August 2010, this switch was located behind the front panel. The normal/test slide switch (not shown) is located on the left-side interior. This switch is only used for
factory testing and must be in the normal position (towards front of relay) for proper operation. Prior to August 2010, this switch was located on the right-side interior. The tap range plate (not shown) indicates the terminal connections (high or low) used to select the current
sensing input range. The sensing input ranges are listed in Table 2. Controls and Indicators BE1-51/27C
9137200998 Rev E 9
Table 2. Sensing Input Ranges
TAP
Range
Plate
or
Pickup
HIGH 2.25 3.00 4.50 5.25 6.75 7.50 9.00 9.75 11.25 12.00 8,7 — — —
LOW 0.75 1.00 1.50 1.75 2.25 2.50 3.00 3.25 3.75 4.00 9,7 — — —
HIGH 2.25 3.00 4.50 5.25 6.75 7.50 9.00 9.75 11.25 12.00 8,7 14,15 17,18 —
LOW 0.75 1.00 1.50 1.75 2.25 2.50 3.00 3.25 3.75 4.00 9,7 13,15 16,18 —
HIGH 2.25 3.00 4.50 5.25 6.75 7.50 9.00 9.75 11.25 12.00 8,7 — 14,15 17,18
LOW 0.75 1.00 1.50 1.75 2.25 2.50 3.00 3.25 3.75 4.00 9,7 — 13,15 16,18
Phase
or
Neutral
Phase 2.25 3.00 4.50 5.25 6.75 7.50 9.00 9.75 11.25 12.00 8,9 13,14 15,16 —
Neutral 0.75 1.00 1.50 1.75 2.25 2.50 3.00 3.25 3.75 4.00 — — — 17,18
A B C D E F G H I J ØA ØB ØC N
Sensing Input Range 1, Two-Phase-and-Neutral *
Sensing Input Range 2, Three-Phase-and-Neutral
0.75 1.00 1.50 1.75 2.25 2.50 3.00 3.25 3.75 4.00 8,9 13,14 15,16 17,18
Sensing Input Range 3, Three-Phase-and-Neutral
TAP Selector
Sensing Input Range 1, Single-Phase *
Sensing Input Range 1, Three-Phase *
Current Sensing
Terminals
Sensing Input Range 4, Three-Phase-and-Neutral
Phase 0.75 1.00 1.50 1.75 2.25 2.50 3.00 3.25 3.75 4.00 8,9 13,14 15,16 —
Neutral 2.25 3.00 4.50 5.25 6.75 7.50 9.00 9.75 11.25 12.00 — — — 17,18
Sensing Input Range 5, Three-Phase-and-Neutral
Phase or
Neutral
Phase or
Neutral
Phase 0.45 0.60 0.90 1.05 1.35 1.50 1.80 1.95 2.25 2.40 8,9 13,14 15,16 —
Neutral 0.15 0.20 0.30 0.35 0.45 0.50 0.60 0.65 0.75 0.80 — — — 17,18
Phase or
Neutral
HIGH 0.45 0.60 0.90 1.05 1.35 1.50 1.80 1.95 2.25 2.40 Same as Range 1
LOW 0.15 0.20 0.30 0.35 0.45 0.50 0.60 0.65 0.75 0.80 Same as Range 1
2.25 3.00 4.50 5.25 6.75 7.50 9.00 9.75 11.25 12.00 8,9 13,14 15,16 17,18
Sensing Input Range 6, Three-Phase-and-Neutral
0.15 0.20 0.30 0.35 0.45 0.50 0.60 0.65 0.75 0.80 8,9 13,14 15,16 17,18
Sensing Input Range 7, Three-Phase-and-Neutral
Sensing Input Range 8, Three-Phase-and-Neutral
0.45 0.60 0.90 1.05 1.35 1.50 1.80 1.95 2.25 2.40 8,9 13,14 15,16 17,18
Sensing Input Range 9 (All Other Sensing Types) *
* For relays with sensing input ranges 1 or 9, connect the system wiring to the current sensing terminals for the desired range (HIGH or LOW).
10 9137200998 Rev E
Refer to Table 3 for target installation configurations.
Table 3. Target Installation Configurations
Number of Instantaneous Elements Targets Installed (Types A and B)
Sensing
Input Type
None One Two
X X
Element Function
A B C N TIME INST 1 INST 2
L
P
T
A
D
J
X X X X X X X
X X X X
X X X X X X
X X X X X
X X X X X X X
X X X X
X X X X X X
X X X X X
X X X X X X X
X X X X
X X X X X X
9137200998 Rev E 11

Functional Description

BE1-51/27C Time Overcurrent Relays are microprocessor-based devices that provide protection for the phase or phase and neutral time and instantaneous overcurrent functions.

Block Diagram Analysis

The following block diagram analysis is referenced to Figure 3. A microprocessor (not illustrated in Figure
3) processes signals, performs logic functions, and all of the time overcurrent computations.
Figure 3. Functional Block Diagram
12 9137200998 Rev E

Power Supply

Operating power for the relay circuitry is supplied by a wide range, electrically isolated, low-burden power supply. Power supply operating power is not polarity sensitive. The front panel power LED and power supply status output indicate when the power supply is operating. Power supply specifications are listed in the Specifications chapter.

Current Sensing

All relay models (except three-phase-and-neutral units) have two sensing ranges for each phase. Each high/low sensing range has its own set of input terminal connections.
• Five ampere CTs have: LOW (0.5 A to 4.0 A) and HIGH (1.5 A to 12.0 A).
• One ampere CTs have: LOW (0.1 A to 0.8 A) and HIGH (0.3 A to 2.4 A).
Three-phase-and-neutral sensing units, however, have one of four possible combinations of input sensing ranges with one range for neutral and one range for the phases.
• Five ampere CTs have: 0.5 A to 4.0 A and 1.5 A to 12.0 A.
• One ampere CTs have: 0.1 A to 0.8 A and 0.3 A to 2.4 A.

Tap Select and Tap Cal

Front panel TAP selectors and TAP CAL controls are provided for selection and precise adjustment of the phase and neutral (if provided) time overcurrent pickup points. The front panel TAP selectors, ten­position BCD weighted rotary switches, select the desired current sensing pickup point, while the front panel TAP CAL controls provide precise adjustment between the selected setting and the next lower setting.

Voltage Sensing

Input voltage for each phase to be monitored is applied to the voltage sensing circuits. Each voltage sensing circuit consists of an input transformer, rectifier, and filter Analog voltages from the voltage sensing circuits are applied to the multiplexor. Note that neutral is not monitored for voltage.

Multiplexor

The multiplexor sequentially switches a voltage representing each of the sensed input currents to the analog-to-digital converter and level detector.

Analog-To-Digital Converter and Level Detector

When the voltage representing the actual sensed inputs meets or exceeds the selected pickup point, this circuit converts the level to a corresponding binary number and applies it to a time trip comparator and scaler circuit and to a counter for calculation of the required time delay.

Time Trip Comparator and Scaler

This circuit accepts both the binary number representing the detected current level and the desired time delay characteristic selected by the front panel TIME DIAL, then computes the required time delay before the timed output relay will be energized. Time delay characteristics are shown in the curves located in the Time Overcurrent Characteristic Curves chapter. If extended timing range options 2-D or 2-E is present, the time delay characteristic curves are modified so that the time delay is approximately 5.7 times the derived value.
Time delay computations are updated continuously so that changes in the overcurrent condition are monitored and result in a corresponding change in the time delay. A software counter begins counting when the initial binary number is received from the analog-to-digital converter and level detector. The counter measures the elapsed time of the overcurrent condition, and resets if the current decreases below the pickup point. This continuously increasing binary number is then passed to the comparator.
9137200998 Rev E 13

Microprocessor (Not Shown)

Some of the circuitry already discussed is part of the microprocessor and no definite lines are drawn to separate the functions. The microprocessor compares the desired time delay (from the time trip comparator and scaler) with the actual elapsed time from the counter. When the elapsed time reaches the intended delay, the timed output relay is energized. During the time delay period, the front panel TIMING indicator (i.e. pickup) associated with the detected phase is illuminated.
If targets are present, the front panel TIME FUNCTION target wi ll be tripped, and t he A, B, C, or N ELEMENT target associated with the detected phase will be tripped. See the Controls and Indicators chapter for the types of targets that are present (depending upon relay configuration).
If option 3 is present, an auxiliary output relay (with N.O., N.C., or SPDT contacts) is also actuated when the timed output relay energizes.

Voltage Inhibit

The output of the multiplexor is applied to the voltage inhibit circuit for comparison with a voltage limit set by the front panel VOLTAGE INHIBIT ADJ control. If the (phase) input voltage exceeds this level, the appropriate front panel VOLTAGE INHIBIT indicator will be illuminated and a voltage inhibit signal will prevent the timed output relay and (if present) the auxiliary output relay from energizing. Instantaneous overcurrent operation, if present , will not be affected.

Instantaneous Overcurrent (Options 1-1 and 1-2)

Input current levels applied to the time overcurrent circuitry are also passed to the instantaneous overcurrent circuitry. These levels are compared to the setting of the front panel INST 1 adjust and the front panel INST 1 (NEUTRAL) adjust (if present). If the input current level is above the setting, the output driver energizes the instantaneous 1 output relay. If the instantaneous 2 option is present, the input level is also compared with the setting of the front panel INST 2 adjust to energize the instantaneous 2 output relay. Note that the current level settings for the instantaneous overcurrent element will always be from 1 to 40 times above the front panel TAP and TAP (NEUTRAL) settings of the time overcurrent element.
If target type A or B is present, the front panel INST 1 tar get and the fr ont pan el INST 2 targets are tripped when their respective output relay is energized, along with the front panel A, B, C or N ELEMENT targets (if present) associated with the detected phases. (See the Controls and Indicators chapter for the types of targets that can be present depending upon the relay configuration.)

Timed and Instantaneous Outputs

Each output signal (representing either time overcurrent or instantaneous overcurrent) from each monitored phase (or neutral) is applied to the respective output driver. Each output driver supplies operating current to energize the associated output relay. Either normally open (output type E) or normally closed (output type G) contacts may be specified. (The contact configurations of all output relays for a given model will be the same.)

Auxiliary Outputs

In addition to the output relays, an auxiliary relay, having the same or a different contact configuration, may be specified. Both the output and the auxiliary relays will remain energized for the duration of the overcurrent condition.

Push-to-Energize Pushbuttons

If either option 2-C or 2-E is present, each individual output relay can be directly energized for test purposes by the actuation of a front panel PUSH-TO-ENERGIZE OUTPUT pushbutton. The pushbutton is actuated by the insertion of a thin, non-conducting rod through an access hole in the front panel.

Power Supply Status Output (Option 3-6)

Power supply status output relays have a set of normally closed contacts that are energized open during power-up. If either or both power supply output legs (+12 Vdc or −12 Vdc) fails, the power supply status
14 9137200998 Rev E
Note
output relay is de-energized and the output contacts close. Shorting bars across the output contacts are held open by the installed connection plug. When the relay is removed from service by removing the connection plug, the shorting bars are closed.

Target Indicators

Target indicators are optional components selected when a relay is ordered. The electronically latched and reset targets consist of red LED indicators located on the relay front panel. A latched target is 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.
A relay can be equipped with either internally operated targets or current operated targets.
Internally Operated Targets
The relay trip outputs are directly applied to drive the appropriate target indicator. Each indicator is illuminated regardless of the current level in the trip circuit.
Current Operated Targets
A current operated target is triggered by closure of the corresponding output contact and the presence of at least 200 milliamperes of current flowing in the trip circuit.
Note that the front panel function targets (TIMED, INST 1, etc.) may be either internally or current operated. Phase and neutral indicators are current operated only if the instantaneous options are not included and if current operated targets are specified.
Prior to August 2007, BE1-51/27C target indic ator s co ns isted of magnetically latched, disc indicators. These mechanically latch ed target indicators have been replaced by the electronically latched LED targets in use today.
9137200998 Rev E 15
Caution
Note

Installation

BE1-51/27C relays are shipped in sturdy cartons to prevent damage during transit. Upon receipt of a relay, check the model and style number against the requisition and packing list to see that they agree. Inspect the relay for shipping damage. If there is evidence of damage, file a claim with the carrier, and notify your sales representative or Basler Electric.
If the relay will not be installed immediately, store it in its original shipping carton in a moisture- and dust­free environment. Before placing the relay in service, it is recommended that the test procedures of the Tests and Adjustments chapter be performed.

Relay Operating Guidel ines and Precautions

Before installing or operating the relay, note the following guidelines and precautions:
• For proper current operated target operation, a minimum current of 200 milliamperes must flow
through the output trip circuit.
• If a wiring insulation test is required, remove the connection plugs and withdraw the relay from its
case.
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, test, or service.
Be sure that the BE1-51/27C is hard-wired to earth ground with no smaller than 12 AWG copper wire attached to the ground terminal on the rear of the case. When the BE1-51/27C is configured in a system with other devices, it is recommended to use a separate lead to the ground bus from each device.

Mounting

Because the relay is of solid-state design, it does not have to be mounted vertically. Any convenient mounting angle may be chosen. Refer to the following figures for relay outline dimensions and panel drilling diagrams.
Figure 4. Panel Cutting/Drilling, Semi-Flush, S1 Case
9137200998 Rev E 17
Figure 5. S1 Case Dimensions, Rear View, Double Ended, Semi-Flush Mount
.75
(19.1)(157.2)
6.19
(49.53)
1.95
10-32 SCREWS
(7.9)
.31
10-32 SCREWS
(102.4)
4.03
4.03
(102.4)
(
7.9)
.31
MOUNTING PANEL
(55.75
)
2.195
P0066-64
Figure 6. S1 Case Dimensions, Side View, Double Ended, Semi-Flush Mount
9137200998 Rev E 19
Figure 7. S1 Case Dimensions, Rear View, Single Ended, Semi-Flush Mount
.75
(19.1)(157.2)
6.19
(49.53)
1.95
10-32 SCREWS
MOUNTING PANEL
(55.75)
2.195
P0066-69
8.06
(204.72)
(7.9)
.31
Figure 8. S1 Case Dimensions, Side View, Single Ended, Semi-Flush Mount
9137200998 Rev E 21
Figure 9. Panel Cutting/Drilling, Double Ended, Projection Mount, S1 Case
Figure 10. S1 Case Dimensions, Rear View, Double Ended, Projection Mount
9137200998 Rev E 23
.
75
(
19
.1
)
(
157.
2)
6.
19
(
49
.53
)
1
.
95
10-
32 SCREWS
(
7.
9
)
.
31
10
-32 SCREWS
(
102.4)
4.
03
4.03
(102.
4)
(7.
9)
.
31
(55
.75
)
2.
195
P0066-
67
TERMINAL EXTENSION
(TYP.) FOR DETAILED INSTRUCITONS, SEE THE TERMINAL PROJECTION MOUNTING KIT SUPPLIED.
.25
(6.
4)
5
/16-
18
STUD
2
PLACES
MOUNTING PANEL
Figure 11. S1 Case Dimensions, Side View, Double Ended, Projection Mount
Figure 12. Panel Cutting/Drilling, Single Ended, Projection Mount, S1 Case
9137200998 Rev E 25
Figure 13. S1 Case Dimensions, Rear View, Single Ended, Projection Mount
(157.2)
6.19
(49.53)
1.95
10-32 SCREWS
MOUNTING PANEL
(55.75)
2.195
P0066-71
TERMINAL EXTENSION (TYP.) FOR DETAILED INSTRUCITONS, SEE THE TERMINAL PROJECTION MOUNTING KIT SUPPLIED.
.25 (6.4)
5/16-18 STUD 2 PLACES
MOUNTING PANEL
8.06
(204.72)
(7.9)
.31
.75 (19.1)
Figure 14. S1 Case Dimensions, Side View, Single Ended, Projection Mount
9137200998 Rev E 27
P
0066-68
Figure 15. S1 Case Cover Dimensions, Front View
P
0050-03

Connections

Be sure to check the model and style number of a relay before connecting and energizing the relay. Incorrect wiring may result in damage to the relay. Except where noted, connections should be made with wire no smaller than 14 AWG.
Typical external and internal connections are shown in the following figures. To prevent an inductive overload of the relay contacts, it is necessary to break the trip circuit extern a lly
through the 52a contacts. Relay circuitry is connected to the case terminals by removable connection plugs (1 plug for 10-terminal
cases and 2 plugs for 20-terminal cases). Removal of the connection plug(s) opens the normally open trip contact circuits and shorts the normally closed trip circuits before opening the power and sensing circuits.
Figure 16. Typical External Connections, Current Operated Targets, DC Powered
9137200998 Rev E 29
P
0050-0
4
P0050-05
Figure 17. Typical Sensing External Connections, Sensing Input Type L
Figure 18. Typical Sensing External Connections, Sensing Input Type P
P005
0-06
P0050-07
Figure 19. Typical Sensing External Connections, Sensing Input Type T
Figure 20. Typical External Connections, Sensing Input Type A
9137200998 Rev E 31
P005
0-08
P0050-09
Figure 21. Typical Sensing External Connections, Sensing Input Type D
Figure 22. Typical Sensing External Connections, Sensing Input Type J
P0050-10
Figure 23. Typical Sensing External Connections, Sensing Input Type P, Unit-Connected
9137200998 Rev E 33
Figure 24. Typical Internal Diagram, Sensing Input Type L
Figure 25. Typical Internal Diagram, Sensing Input Type J
9137200998 Rev E 35
Figure 26. Typical Internal Diagram, Sensing Input Type A
Figure 27. Typical Internal Diagram, Sensing Input Type P
9137200998 Rev E 37
Figure 28. Typical Internal Diagram, Sensing Input Type D
Figure 29. Typical Internal Diagram, Sensing Input Type T
9137200998 Rev E 39

Maintenance

BE1-51/27C 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 aluminum 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.
9137200998 Rev E 41
Note
Note

Tests and Adjustments

Procedures in this section are for use in testing and adjusting a relay for the desired operation in a protective scheme. If a relay fails an operational test, or if an adjustment discloses a faulty relay, contact Basler Electric.

Required Test Equipment

Minimum test equipment required for relay testing and adjustment is listed below. Refer to the following figures for test setups.
• Appropriate ac or dc power source for relay operation
• Appropriate ac source (50- or 60-hertz as appropr iat e) for volta ge and current testing
• Dc external power source for output relay(s) test setup and timer input
• Relay test set capable of delivering 40 amperes. A higher capability is needed for instantaneous
settings above 40 amperes
• Timer
• One shunt resistor for providing minimum target load

Operational Test

Preliminary Instructions

Perform the following steps before going on to any testing. Step 1. Connect the relay test setup in accordance with Figures 30 through 35, depending upon the
sensing input type for your relay (see the style chart in the General Information chapter). (a) Sensing Input Type L (Single-Phas e Sens i ng). Refer to Figure 30
For relays having the above sensing, only the from panel LOW range current sense terminal(s) should be connected for a complete check of the relay.
Ensure that timed output termina ls 1 and 10 are conn e cted.
(b) Sensing Input Type P (Three-Phase Sensing). Refer to Figure 31
For relays having the above sensing, only the from panel LOW range current sense terminal(s) should be connected for a complete check of the relay.
.
.
For all three-phase relays, the test signals must connect to both the current and voltage terminals for the same phase.
Ensure that timed output termina ls 1 and 10 are conne c ted.
42 9137200998 Rev E
(c) Sensing Input Type T (Three-Phase with Neutral Sensing). Refer to Figure 32.
Ensure that the timed output terminals 1 and 10 are connected. Also, verify that either A, B, or C current sense terminals are connected initially (N terminals will be connected later in the test).
(d) Sensing Input Type A (Three-Phase Sensing). Refer to Figure 33
.
Ensure that the timed output terminals 1 and 10 are connected. Also, verify that either A, B, or C current sense terminals are connected initially (N terminals will be connected later in the test). Ensure that the voltage sense terminals and the current sense terminals are connected to the same phase.
(e) Sensing Input Type D (Three-Phase with Neutral Sensing). Refer to Figure 34
.
Ensure that the timed output terminals 1 and 10 are connected. Also, verify that either A, B, or C current sense terminals are connected initially (N terminals will be connected later in the test).
(f) Sensing Input Type J (Two-Phase with Neutral Sensing). Refer to Figure 35
.
Ensure that the timed output terminals 1 and 10 are connected. Also, verify that either A, B, or C current sense terminals are connected initially (N terminals will be connected later
in the test). Step 2. Remove the relay front cover. Step 3. Set the front panel TIME DIAL selector and, if present, the front panel TIME DIAL (NEUTRAL)
selector to 99. Step 4. Adjust the front panel INST 1 and INST 2 controls, if present, fully clockwise (CW). Step 5. Adjust the front panel TAP CAL control, and if present, the front panel TAP (NEUTRAL) control
fully CW. Step 6. Ensure that the relay front panel TARGETS, if present, are reset. Step 7. Apply 100% of nominal voltage based on the sensing input type for your relay.
Figure 30. Test Setup for Sensing Input Type L (Single-Phase Sensing)
9137200998 Rev E 43
Figure 31. Test Setup for Sensing Input Type P (Three-Phase Sensing)
Figure 32. Test Setup for Sensing Input Type T (Three-Phase with Neutral Sensing)
44 9137200998 Rev E
Figure 33. Test Setup for Sensing Input Type A (Three-Phase, Delta Configuration)
Figure 34. Test Setup for Sensing Input Type D (Three-Phase with Neutral Sensing)
9137200998 Rev E 45
Note
Figure 35. Test Setup for Sensing Input Type J (Two-Phase with Neutral Sensing)

Time Overcurrent Pickup Test

This test checks the minimum and maximum overcurrent pickup points of the time overcurrent element.
During this test, disregard any indication on the test setup timer.
Step 1. Perform the preliminary instructions. Step 2. Set the front panel TAP selector to A. Step 3. Adjust the test set, for an overcurrent threshold having one of the following values:
(a) 0.5 for relays with Sensing Input Range 1, 2, or 4.
(b) 1.5 A for relays with Sensing Input Range 3 or 5. Step 4. Slowly adjust the front panel TAP CAL control CCW until the front panel TIMING indicator
illuminates. RESULT: For the phase minimum overcurrent pickup point of 0.5 A (Step 3a, above) or 1.5 A
(Step 3b, above) the front panel TAP CAL control should be near its maximum CCW limit. Step 5. Adjust the front panel TAP CAL control fully CW to allow measurement of the actual
overcurrent pickup point at the A setting of the front panel TAP selector. Note that the front
panel TIMING indicator wil l exting uis h. Do not disturb t his sett ing. Step 6. Slowly increase the current toward the value of the front panel TAP selector A setting until the
front panel TIMING indicator illuminates. Do not disturb this setting. Step 7. Record the current reading and remove input current. RESULT: The recorded value should be within ±5% of the front panel TAP selector A setting
for the phase minimum overcurrent pickup point for the time overcurrent.
46 9137200998 Rev E
Note
Step 8. Set the front panel TAP selector to J. Step 9. Slowly adjust the test set, increasing the overcurrent threshold toward the value of the front
panel TAP selector J setting until the front panel TIMING indicator just illuminates. Do not
disturb this setting. Step 10. Record the current reading and remove input current. RESULT: The recorded value should be within ±5% of the front panel TAP selector J setting for
the phase maximum overcurrent pickup point for the time overcurrent element. Step 11. Perform the following steps as appropriate for the correct sensing input types.
Ensure that the voltage sense terminals and current sense terminals are connected to the same phase.
(a) Sensing Input Type L (Single-Phas e Sens i ng). This concludes the time overcurrent test.
Proceed to the timed output test.
(b) Sensing Input Type J (Two-Phase and Neutral Sensing) . Remove the power and
reconnect the input sensing to the remaining phases as shown in Figure 35, each time repeating Steps 1 through 10. For neutral testing, continue with Step 12.
(c) Sensing Input Type A and P (Three-Phase Se ns ing). Remove the power and reconnect
the input sensing to each of the remaining phases as shown in Figures 33 and 35, each time repeating Steps 1 through 10.
(d) Sensing Input Type D and U (Three-Phase with Neutral Sensing). Remove the power
and reconnect the input sensing to each of the remaining phases as shown in Figures 32 and 34, each time repeating Steps 1 through 10. For neutral testing, continue with Step
12. Step 12. Perform the preliminary instructions. For the neutral sensing (terminals 17 and 18), connect the relay as shown in Figures 32 and 34,
then perform the following steps (Steps 13 through 21). Step 13. Set the front panel TAP (NEUTRAL) selector to A. Step 14. Adjust the test set for an overcurrent threshold having one of the following values:
(a) 0.5 A for relays with Sensing Input Range 2 or 3.
(b) 1.5 A for relays with Sensing Input Range 4 or 5. Step 15. Slowly adjust the front panel CAL (NEUTRAL) control CCW until the front panel TIMING
indicator illuminates. RESULT: For the neutral minimum overcurrent pickup point of 0.5 A (Step 16a, above) or 1.5 A
(Step 16b, above) the front panel CAL (NEUTRAL) control should be near its maximum CCW
limit. Step 16. Adjust the front panel CAL (NEUTRAL) control fully CW to allow measurement of the actual
overcurrent pickup point at the A setting of the front panel TAP (NEUTRAL) selector. Note that
the front panel TIMING (NEUTRAL) indicator will extinguish. Do not disturb this set ting. Step 17. Slowly increase the current toward the value of the front panel TAP (NEUTRAL) selector A
setting until the front panel TIMING (NEUTRAL) indicator illuminates. Do not disturb this
setting. Step 18. Record the current reading and remove input current.
9137200998 Rev E 47
Note
Note
RESULT: The recorded value should be within ±5% of the front panel TAP (NEUTRAL)
selector A setting for the neutral minimum overcurrent pickup point for the time overcurrent. Step 19. Set the front panel TAP (NEUTRAL) selector to J. Step 20. Slowly adjust the test set, increasing the overcurrent threshold toward the value of the front
panel TAP (NEUTRAL) selector J setting until the front panel TIMING (NEUTRAL) indicator
just illuminates. Do not disturb this setting. Step 21. Record the current reading and remove input current. RESULT: The recorded value should be within ±5% of the front panel TAP (NEUTRAL)
selector J setting for the neutral maximum overcurrent pickup point for the time overcurrent
element.

Timed Output Test

This test checks the accuracy of the time overcurrent characteristic delay.
For relays having three-phase sensing (Sensing Input Type A or P) only a single input phase needs to be connected, since this is sufficient for a complete test of the Time Delay. For relays that include neutral sensing (Sensing Input Type D, T, or J), this test includes reconnecting the Test Output to the Neutral Sensing termina ls for testing the Timed Output during neutral sensing.
Step 1. Verify that the preliminary instructions have been performed. Step 2. (Timing type Z1, Z2, or Z3 only.) Select the desired time current characteristic curve. Step 3. Set the front panel TAP selector to B. Step 4. Adjust the front panel TIME DIAL to 20. Step 5. Adjust the test set for an overcurrent threshold of precisely 5 times the front panel TAP selector
B setting. Step 6. Apply input current to the relay and initiate the test setup timer. Step 7. Observe that the appropriate front panel TIMING indicator illuminates and when the time delay
ends that the timed output relay is energized. RESULTS: (1) The appropriate front panel TIMING indicator extin g uis hes .
(2) The test setup timer stops. (Record count for use in Step 9.) (3) If target type A or B is present:
(a) The front panel FUNCTION-TIME target (if present) trips. (b) The appropriate front panel ELEMENT target A, B, or C (if present)
trips.
Step 8. Remove input current and (if present) reset the relay front panel targets.
Due to delays inherent in the test equipment, the time delay for the following test may appear to exceed these limits.
48 9137200998 Rev E
Note
Step 9. On the appropriate time overcurrent curve chart (in the Time Overcurrent Characteristic Curves
chapter), locate the line representing 5 times the tap value (from Step 5) where it intersects the
particular curve representing the front panel TIME DIAL setting of 20 (from Step 4). The
resulting time delay value in seconds should be within ±5% of the timer reading [from Step
7(2)]. Step 10. Adjust the front panel TIME DIAL to 40, 60, and 99, each time repeating Steps 6 through 9.
For relays having two-phase-and-neutral, three-phase, or three-phase­and-neutral sensing (Sensing Input Types A, D, P, T, or J) it is not necessary to repeat this test for the remaining phases.
For relays having two-phase-and-neutral, or three-phase-and-neutral sensing (Sensing Input Types D, T, or J) perform Steps 11 through 20.
For relays having single-phase or three-phase sensing (Sensing Input Types A or P) with instantaneous overcurrent option 1-1 or 1-2, proceed to the instantaneous overcurrent test.
Step 11. Remove the power and reconnect the test output to the neutral current sensing input of the
relay as shown in Figures 32 and 34 (terminals 17 and 18). Step 12. Set the front panel TAP (NEUTRAL) selector to B. Step 13. Rotate the front panel CAL (NEUTRAL) control fully CW. Step 14. Rotate the front panel TIME DIAL (NEUTRAL) to 20. Step 15. Ensure that all relay targets have been reset. Step 16. Adjust the test set for an overcurrent threshold of precisely 5 times the front panel TAP
(NEUTRAL) selector B setting as meas ur ed by the ammet er. Step 17. Apply input current to the relay and initiate the test setup timer. RESULTS: Observe that the appropriate front panel TIMING (NEUTRAL) indicator illuminates. Step 18. When the time delay ends, the timed output relay is energized. RESULTS: (1) The front panel TIMING (NEUTRAL) indicator extinguishes. (2) The test setup timer stops. (Record count for use in Step 20.) (3) If target Type A or B is present: (a) Front panel FUNCTION-TIME target (if present) trips. (b) Appropriate front panel ELEMENT target A, B, or C (if present) trips. Step 19. Remove input current and (if present) reset the relay front panel targets. Step 20. On the appropriate time overcurrent curve chart (in the Time Overcurrent Characteristic Curves
chapter), locate the line representing 5 times the tap value (from Step 5) where it intersects the
particular curve representing the front panel TIME DIAL (NEUTRAL) setting of 20 (from Step
14). The resulting time delay value in seconds should be within ±5% of the timer reading [from
step 18(2)].
9137200998 Rev E 49
Note
Note
Due to delays inherent in the test equipment, the time delay may appear to exceed these limits. This concludes the timed output test.
Relays having instantaneous overcurrent option 1-1 or 1-2 only proceed to the Instantaneous Overcurrent Pickup Test.

Instantaneous Overcurrent Pickup Test

This test checks the minimum overcurrent pickup points for Instantaneous 1 and (if present) Instantaneous 2 outputs.
For relays having three-phase sensing (Sensing Input Types A or P), only a single input phase is connected since this is sufficient for a complete test of the instantaneous overcurrent sensing and output.
For relays that include neutral sensing (Sensing Input Types D, T, or J), this test includes reconnecting the test output to the neutral sensing terminals for testing the instantaneous 1 output during neutral sensing.
Step 1. Perform the preliminary instructions. Step 2. Reconnect the test setup to the INST 1 output terminals 2 and 10 as shown in Figures 30
through 35. Note that the timer may be removed from the test setup at this time. Step 3. Set the TAP selector to A. Step 4. Turn the front panel INST 1 control fully CCW to establish a pickup point of 1 times the TAP
selector A setting. Step 5. Slowly adjust the test set, increasing the overcurrent threshold toward the value of the front
panel TAP selector A setting until the Instantaneous 1 output relay energizes. RESULT: If target Type A or B is present: (a) The front panel FUNCTION-INST 1 target (if present) will trip. (b) The appropriate front panel ELEMENT target A, B, or C (if present) will trip. Step 6. Remove input current. Record the test set current setting. RESULT: The recorded value should be equal to or less than the front panel TAP selector A
setting for the minimum overcurrent pickup point for the instantaneous 1 overcurrent element. Step 7. Reset the relay front panel targets (if present). Step 8. Turn the front panel INST 1 control fully CW to establish a pickup point of 40 times the front
panel TAP selector A setting. Step 9. Adjust the test set to approximately 35 times the front panel TAP selector A setting. Step 10. Slowly adjust the test set further toward an overcurrent threshold of 40 times the front panel
TAP selector A setting until the instantaneous 1 output relay energizes. Do not disturb this
setting. RESULT: If target Type A or B is present: (a) The front panel FUNCTION-INST 1 target (if present) will trip. (b) The appropriate front panel ELEMENT target A, B, or C (if present) will trip.
50 9137200998 Rev E
Note
Note
Step 11. Record the current reading. Remove input current (the front panel TIMING indicator should
extinguish).
RESULT: The recorded value should be greater than 40 times the front panel TAP selector A
setting for the maximum overcurrent pickup point for the instantaneous 1 overcurrent element.
For relays having neutral sensing (Sensing Input Types D, T, or J) perform Step 12. Otherwise, proceed to Step 13.
Step 12. For the neutral sensing, connect the relay as shown in Figures 32 and 34, then repeat Steps 2
through 11, substituting the following:
(a) The front panel TAP (NEUTRAL) selector instead of the front panel TAP selector (Step 3).
(b) The front panel INST 1 (NEUTRAL) control instead of the front panel INST 1 control
(Step 4)
For relays with Option 1-2 (Inst. 2 elements), perform Step 13. Otherwise, the test ends here.
Step 13. Reconnect the test setup to the INST 2 output terminals (11 and 12) as shown in Figure 30,
then repeat Steps 4 through 11, substituting the following: (a) Front panel INST 2 control instead of the front panel INST 1 control (Step 3). (b) Front panel FUNCTION-INST 2 target instead of the front panel INST 1 target ( Step 4). (c) Instantaneous 2 output relay instead of the instantaneous 1 output relay ( Step 2).

Voltage Control Test

This test checks the voltage control minimum and maximum limits for the voltage inhibit levels. Step 1. Perform the Preliminary Instructions. Step 2. Set the front panel TAP selector to B. Step 3. Adjust the front panel TIME DIAL to 20. Step 4. Adjust for an overcurrent threshold of 2 times the front panel TAP selector B setting. Step 5. Rotate the front panel VOLTS INHIBIT ADJ or VOLTAGE INHIBIT ADJ fully CCW. Step 6. Adjust the test voltage to its minimum voltage setting, and then slowly increase the voltage until
the appropriate front panel VOLTS INH I BIT or VOLT A GE INHI BIT ind icator just ill umi nates . Do
not disturb this setting. RESULT: The voltage should be <40 Vac. Step 7. Apply input current to the relay and initiate the test setup timer.
RESULT: The front panel TIMING indicator does not illuminate which signifies that the relay-
timed output is inhibited. Step 8. Remove input current and reset the test setup timer. Step 9. Rotate the front panel VOLTS INHIBIT ADJ or VOLTAGE INHIBIT ADJ fully CW.
9137200998 Rev E 51
Note
Note
Step 10. Adjust the test voltage for a 110 Vac output, and then slowly increase its output voltage until the
appropriate front panel VOLTS INHIBIT or VOLTAGE INHIBIT indicator just illuminates . RESULT: The voltage should be >120 Vac.
For relays having two-phase-and-neutral sensing, three-phase sensing, or three-phase-and-neutral sensing (sensing input types A, D, P, T, or J) remove power and reconnect the input sensing to each of the remaining phases (see Figures 31 through 35), each time repeating Steps 1 through 10. Ensure that the voltage sense terminals and the current sense terminals are connected to the same phase.
When all phases have been tested, the voltage control test is concluded. If the instantaneous overcurrent Option 1-1 or 1-2 is present, proceed to instantaneo us overcurrent pickup.

Adjustments of Controls f or Rel a y Operation

The following procedures set up the relay for use in a protective scheme. The procedures are arranged in a logical sequence that prevents upsetting previous control settings. For relays not having certain options, skip the corresponding adjustment paragraph. These paragraphs are identified by their headings.

TAP and TAP (NEUTRAL) Selector Setting

Selection of one of the specific overcurrent pickup points provided by the front panel TAP selector (and with the front panel TAP CAL control fully CW) will permit a pickup point within ±5% of the selector value without having to connect the relay to a test setup to verify the setting. If present, the front panel TAP (NEUTRAL) selector and the front panel CAL (NEUTRAL) control provide this function for the neutral overcurrent pickup point.
However, if the desired pickup point falls between these front panel TAP selector settings, or if the instantaneous overcurrent option 1-1 or 1-2 is present, the relay should be connected to a test setup for a precise setting, then the following steps should be performed.
Step 1. Connect the test setup to the relay according to the sensing input type present in the relay as
follows:
(a) Sensing Input Type L: Refer to Figure 30
provides the needed pickup indication, do not connect the test setup to the output terminals. The current sense terminals for the desired range (HIGH or LOW), however, should be connected to the relay.
. Because the relay front panel TIMING indicator
(b) Sensing Input Type J: Refer to Figure 35. Because the relay front panel TIMING indicator
provides the needed pickup indication, do not connect the test setup to the output terminals. The front panel TAP selector is ganged and the adjustment of one input phase automatically aligns the other, thus, only one set of current sense terminals need be connected. For adjustment of the front panel TAP (NEUTRAL) selector, the relay is reconnected for neutral sensing by this procedure.
52 9137200998 Rev E
Note
Note
(c) Sensing Input Types A or P: Refer to Figures 31 and 33. Because the relay front panel
TIMING indicator provides the needed pickup indication, do not connect the test setup to the output terminals. The desired range terminals (HIGH or LOW), however, should be connected to the relay. The front panel TAP selector is ganged and the adjustment of one input phase automatically aligns the others, thus, only one set of current sense terminals need be connected.
(d) Sensing Input Types D or T: Refer to Figures 32 and 34. Because the relay front panel
TIMING indicator provides the needed pickup indication, do not connect the test setup to the output terminals. The front panel TAP selector is ganged and the adjustment of one input phase automatically aligns the others, thus, only one set of current sense terminals need be connected. For adjustment of the front panel TAP (NEUTRAL) selector, the relay is reconnected for neutral sensing by this procedure.
For three-phase relays, ensure that the test signals are connected to both the current and voltage terminals for the same phase.
Step 2. Remove the relay front cover. Step 3. Sensing Input Types L or P. Verify that the front panel TAP RANGE plate is installed and the
correct range (HIGH or LOW) is visible. Step 4. Adjust the test voltage to 0 Vac and current to the desired time overcurrent pickup point for the
relay. Step 5. Set the front panel TAP selector to the closest setting above the desired pickup point. Step 6. Adjust the front panel TAP CAL control fully CW. Step 7. Apply current to the relay. Step 8. Slowly adjust the front panel TAP CAL control CCW until the front panel TIMING indicator just
illuminates which indicates the desired time overcurrent pickup point for phase sensing. For
relays with two-phase-and-neutral, three-phase, or three-phase-and-neutral sensing, this
pickup point will be the same for all the phases. Step 9. Remove input current.
For relays with two-phase-and-neutral or three-phase-and-neutral sensing (Sensing Input Types D, T, or J), perform Steps 10 through
15. Otherwise, the time overcurrent pickup point calibration ends here (unless instantaneous 1 or 2 overcurrent calibration is to be performed later in these procedures).
Step 10. Reconnect the test set output to the neutral sense terminals. See Figures 32, 34, or 35. Step 11. Adjust the current to the desired time overcurrent pickup point for the relay. Step 12. Set the front panel TAP (NEUTRAL) selector to the closest setting above the desired pickup
point. Step 13. Rotate the front panel CAL (NEUTRAL) control fully CW. Step 14. Slowly adjust the front panel CAL (NEUTRAL) control CCW until the front panel TIMING
(NEUTRAL) indicator just illuminates to establish the desired time overcurrent pickup point for
neutral sensing.
9137200998 Rev E 53
Note
Note
Step 15. Remove input current.
Pickup point calibration ends here.

Time Overcurrent Curve Selection (Timing Type Z1, Z2, and Z3 Only)

Step 1. Remove the relay cradle front cover to gain access to the logic board time overcurrent
characteristic curve selector. Step 2. Remove the Phillips screws from both sides of the unit and remove the front panel. See the
Controls and Indicators chapter for the location of the logic board and curve selector. Step 3. Select the desired curve. See the Time Overcurrent Characteristic Curves chapter for the
desired curve and selector position. Step 4. Re-insta ll the front pan el an d the front cover .

Time Delay Selection

If Timing Type Z1, Z2, or Z3 is installed, refer to time overcurrent curve selection to obtain the desired set of time overcurrent curves (see the Time Overcurrent Characteristic Curves chapter). Then proceed to Step 1, following.
If Timing Type Z1, Z2, or Z3 is not installed, determine the timing type from the model and style number for a specific relay. Then select the appropriate timing curve (see the Time Overcurrent Characteristic Curves chapter). Proceed to the following, Step 1.
Step 1. Referring to the appropriate time overcurrent characteristic curve, select the desired time delay
on the front panel TIME DIAL for the anticipated input overcurrent difference (multiples-of-
pickup current) from the selected time overcurrent pickup point as follows: (Selected Pick up Po int) - (Anticipated Input Overcurrent) = Overcurrent Difference from Pickup Step 2. Set the front panel TIME DIAL as follows:
(a) On the appropriate curve, plot upward from the multiples-of-pickup-current value until the
horizontal line opposite the desired ti me delay (time-in-seconds) is reached. The setting curve nearest the plot point should then be entered on the front panel TIME DIAL.
(b) Using the timing type B3, Definite Time Curve in the Time Overcurrent Characteristic
Curves chapter as an example, if the overcurrent is expected to be 4 times the pickup point value and time delay of 4 seconds is desired, plot upward from the point 4 on the multiples-of-pickup-current axis until the point 4 from the time-in-seconds axis is crossed. The curve for a setting of 52 crosses the plot point and should be entered on the front panel TIME DIAL.
(c) For a lesser overcurrent difference from the pickup point, the time delay will be greater, so
that for a multiple of 3 times the pickup current, the time delay for the previous front panel setting of 52 will be 5.8 seconds.
54 9137200998 Rev E
Note
Caution
INST 1, INST 1 (NEUTRAL)
INST 2

Neutral Time Delay Selection

Step 1. Use the same characteristic curve used in the previous paragraph (Time Delay Selection).
However, the multiples-of-pickup current, time-in-seconds, and the resulting front panel
NEUTRAL TIME DIAL setting can differ. Step 2. Set the front panel NEUTRAL TIME DELAY as follows:
(a) On the appropriate curve, plot upward from the multiples-of-pickup-current value until the
horizontal line opposite the desired ti me delay (time-in-seconds) is reached. The setting curve nearest the plot point should then be entered on the front panel NEUTRAL TIME DELAY.
(b) Using the timing type B3, Definite Time Curve in the Time Overcurrent Characteristic
Curves chapter as an example, if the overcurrent is expected to be 4 times the pickup point value and time delay of 4 seconds is desired, plot upward from the point 4 on the multiples-of-pickup-current axis until the point 4 from the time-in-seconds axis is crossed. The curve for a setting of 52 crosses the plot point and should be entered on the front panel NEUTRAL TIME DIAL.
(c) For a lesser overcurrent difference from the pickup point, the time delay will be greater, so
that for a multiple of 3 times the pickup current, the time delay for the previous front panel setting of 52 will be 5.8 seconds.

VOLTS INHIBIT ADJ or VOLTAGE INHI BIT ADJ Setting

Step 1. Verify that the test setup is performed. Step 2. Adjust the test voltage to the desired inhibit level (between 40 and 120 Vac). Step 3. Starting at fully CCW, slowly adjust the front panel VOLTS INHIBIT ADJ or VOLTAGE INHIBIT
ADJ CW until the appropriate front panel VOLTS INHIBIT or VOLTAGE INHIBIT indicator
begins flickering. Slowly continue adjusting CW until the indicator first appears solidly
illuminated (no flicker). Do not turn any farther than is needed to remove any visible flicker. The
voltage inhibit level is now established. If multiple phases are sensed by the relay, all phases
will have the same voltage inhibit level.
Because the lower limit for this pickup is determined by the front panel TAP selector setting and the front panel TAP (CAL) control position, ensure that these adjustments have been performed as in the paragraph TAP and TAP (NEUTRAL) Selector Setting.

INST 1 Control Setting

Step 1. Verify that the test setup is as described in TAP and TAP (NEUTRAL) Selector Setting, Steps 1
through 6. Step 2. Connect the test setup to the instantaneous 1 element output terminals (2 and 10) as shown in
Figures 30 through 35. The timer should not be connected.
Steps 3 through 8 provide the application of overcurrent for short periods to allow adjustment while avoiding overheating of the input sensing transformers. To avoid damaging the relay, do not attempt to apply a constant high level of input current for adjustment of the front panel
, or
controls.
9137200998 Rev E 55
Note
Step 3. Set the front panel INST 1 control to a position approximating the desired instantaneous 1
overcurrent pickup point for the relay. Step 4. Apply current to the relay. Step 5. Rapidly increase the overcurrent input to the relay until the instantaneous output relay just
energizes. Note the overcurrent threshold reading on the ammeter. Step 6. Remove input current. Step 7. Reset the INST TARGET (if present). Step 8. If the overcurrent threshold reading from Step 5 was too high or low, adjust the front panel INST
1 control CCW to lower (or CW to raise) the instantaneous 1 overcurrent pickup point. Repeat
Steps 4 through 8. If the overcurrent threshold reading from Step 5 was NOT too high or low,
proceed to Step 9.
For relays with two-phase-and-neutral or three-phase-and-neutral sensing (Sensing Input Types D, T, or J), perform Steps 9 through 14.
Step 9. Reconnect the output to the neutral current sense terminals. See Figures 32, 34, or 35. Step 10. Set the front panel INST 1 (NEUTRAL) control to a position approximating the desired neutral
instantaneous 1 overcurrent pickup point for the relay. Step 11. Apply current to the relay. Step 12. Rapidly increase the overcurrent input to the relay until the instantaneous output relay just
energizes. Note the test set overcurrent threshold reading on the ammeter. Step 13. Remove the input current. Step 14. Reset the INST TARGET (if present). Step 15. If the overcurrent threshold reading from Step 13 was too high or low, adjust the front panel
INST 1 (NEUTRAL) control CCW to lower (or CW to raise) the Neutral Instantaneous 1
Overcurrent Pickup Point. Repeat Steps 9 through 14. If NOT, proceed to the next test.

INST 2 Control Setting

For this adjustment, repeat INST 1 Control Setting, but substitute instantaneous 2 output terminals (11 and 12) and the front panel INST 2 controls. Because neutral sensing does not apply to this pickup point, ignore Steps 9 through 15.

Setting the Relay

General

Neutral (ground) time overcurrent and all instantaneous overcurrent functions operate independently of the voltage control circuits so that these elements can be set conventionally. These optional functions are set independently of each other except that the instantaneous setting is 1 to 40 times the associated time overcurrent element pickup.
Set the instantaneous elements pickup at least at 120 percent of the maximum current that can be seen by the relay for an external fault where operation is not desired. Time settings for the time overcurrent elements can be chosen as if the relay had no voltage sensing elements. This makes it easier to coordinate with other external protection. Set the phase element pickup for about 50 percent of the rated current for a generator backup function. Neutral time overcurrent pickup must be set above the maximum expected normal unbalance. In addition, in the case of residually connected elements, added relay current can result from dissimilar errors in the three current transformers. This error will be greater for the
56 9137200998 Rev E
lower accuracy-class voltages. A neutral element pickup of 10 percent of the circuit rating is normally enough to be above any non-fault unbalance for a solidly grounded system. Lower settings are appropriate and safe for impedance-grounded systems or for ungrounded, protected-equipment connections.
Undervoltage settings should be as high as possible without allowing operation under the worse no-fault conditions. An 85 percent of rated voltage setting meets these requirements. If motor starting or motor accelerating following a fault can severely depress the relay voltage, a setting of 75 percent or 80 percent may be advisable.

Setting Example

Figure 36 illustrates generator relay elements that are to be set in this example. Plant 11 kV feeders are supplied by a 115 kV system that is supplemented by two local 3,700 kVA generators. Line 1 is illustrated completely; line 2 is the same as line 1 and only shows major components. Settings are provided for the BE1-51/27C Time Overcurrent Relay with voltage control, BE1-51 Time Overcurrent Relay, and BE1-67 Phase Directional Overcurrent Relay.
Generator Backup (Breaker A)
• BE1-51/27C (51/27), relay style number: T3E B6S B2C0F
• Three-phase-and-neutral overcurrent
• 1.5 to 12 A phase (instantaneous trip is out of service)
• 0.5 to 4 A neutral (instantaneous is in service)
• Very inverse timing (B6)
• 300/5 CTs
Feeder (Breaker F)
• BE1-51 (51)
• 0.5 to 12 A
• Very inverse timing (B6)
• 800/5 CTs
• No instantaneous
• Pickup set to 6 A
• Time Dial set to 08
Phase Directional (Breaker L)
• BE1-67 (67)
• 0.5 to 12 A
• Definite timing (B3)
• 3,000/5 CTs
• Pickup set to 0.5 A
• Time Dial set to 02
Generator Reactance (Per Unit)
Sub transient ........... 0.18
Transient ................. 0.25
Steady State ........... 1.5
9137200998 Rev E 57
Fault Current - A @ 11 kV
Downstream
Generator
Transient
T2
1
7256
776
Steady State
T2
1
5961
129
Transient
―
2
7256
776
Transient
T2
2
1552
776
Steady State
T2
2
258
129
Transient
―
3
713
713
Steady State
―
3
127
127
( )
7.6
960
7256
6800/5
7256
==
Figure 36. System Example
Downstream current in Table 4 is the current in the downstream relay with which the BE1-51/27C elements must coordinate. The currents are the changes resulting from the fault assuming a driving point voltage of 11 kV. Actual currents will be the sum of the table values plus the pre-fault load currents. Transient level currents are based on use of the generator transient reactance. Steady-state level currents are based on use of generator steady-state reactance and assuming no generator regulator boost. Note that the table values apply for 3-phase faults. Transient level currents in generators for a phase-to-phase fault will be about equal to the 3-phase current values. Steady-state level currents in the generators will be higher for a phase-to-phase fault.
Table 4. Three-Phase Fault Currents
Level Out of Service Fault Loc.

Coordination with Feeder 51 Relay for Fault 1

(1) Multiples of pickup in 51 relay at transient level:
58 9137200998 Rev E
( )
( )
Primary A 97
1.73 11
3700 0.5
=
(
)
A1.6
300/5
97
=
A776 @ s 0.61 0.3 31.0 =+
0
.8
97
776
=
( )
2.6
6 800/5
5961
=
3.1
97
129
=
( )
24
3000/5 5.0
7256
=
3
300
1552
=
86.0
300
258
=
(2) Relay 51 time at 7.6 multiples (from B6 curves) @ 08 time dial: 0.31 s. (3) Set 51/27 pickup:
(4) Set the 51/27 time to provide 0.3 s coordinating interval:
(5) 51/27 voltage equals 0, so the time element is operative. (6) 51/27 multiples:
(7) 51/27 TIME DIAL (from B6 curve, @ 8.0 multiple): 22. (8) Multiples of pickup in the 51 relay at steady-state level:
(9) 51/27 relay time at 6.2 multiples: 0.37 s. (10) 51/27 multiples at 129 A:
(11) 51/27 time at 1.3 multiples: 13.0 s (approx.). (12) Relay 51/27 coordinates with relay 51 over the full range of fault currents with transformer T2 out of
service. With both T1 and T2 in service, relay 51 sees more current and operates faster than the above times. If the fault is not interrupted by the feeder breaker, the generators will be tripped at time falling between 0.61 s and 13.0 s.

Checking Coordination with Relay 67 for Fault 2

(1) 67 multiples at transient level with T2 in service:
(2) 67 time at 24 multiples (B3 curve, TIME DIAL 02): 0.15 s. (3) 67 multiples at transient level with T2 out of service:
(4) 67 time at 3 multiples: 0.23 s. (5) Note that a failure of the differential protection (87T) for fault 2 with T2 out of service is a double
contingency. Coordination of 51/27 relays with 67 relays does occur at the transient level (0.61 vs.
0.35 s). As the current decays, the times converge and cross because the 67 Relay pickup is 300 amperes vs. 97 amperes for 51/27 relays (see calculation below for steady-state multiple of 0.86 for the 67 relays). So coordination may not be achieved for this double contingency with the generator regulators out of service. Boosting by the regulators will partially arrest the decay of current. In addition, the decay will be less for a phase-phase fault.
(6) 67 multiples at steady-state level with T2 out:
9137200998 Rev E 59
4.2
300
713
=
4.7
97
713
=
(7) For a failure of Breaker L to open, the 51 relays on transformer T2 will operate as well as the
generator relays to clear fault 2. For a failure of the T1 differential relays (87T), the T2 51 relays should coordinate with the 67 relays so T2 and the generators will remain in service.

Checking Coordination with Relay 67 for Fault 3

(1) 67 multiples at transient level with T2 in service:
(2) 67 time at 2.4 multiples: 0.26 s. (3) 51/27 transient level voltage (reactor and transformer T1 drop): 8%. (4) 51/27 multiples at transient level:
(5) 51/27 transient level time at 7.4 multiples and TIME DIAL setting of 22: 0.72 s. (6) 51/27 relays coordinate with 67 relays for a high-side fault at the transient level. However, it
appears that the current may drop below the 67 relays pickup (300 amperes) before this relay can operate. Should the 67 relays fail to operate, the 51/27 relays will trip the generators. Figure 37 plots these two relay characteristics. If the generator is fully loaded at 194 amperes with a 0.85 PF, the superposition of this current and the fault current at −90° yields a total current of 831 amperes at the transient level and 282 amperes at the steady-state level with no regulator boosting. The relays are selective down to about 350 amperes.
Figure 37. Relay 51/27 Coordination with Relay 67 for Fault 3 Example
60 9137200998 Rev E
A9704852 =×
DIALTIME 08 and multiples 20
0.860
970
=
×
7.6
0.8
5
=
pickupRelay the times 2.3
300
970
=
(7) Assuming that the 67 relays will not operate for fault 3, the generators will be unnecessarily tripped
if the line relaying fails to operate or if breaker R fails to interrupt the fault. Redundant line relaying will minimize the need for generator tripping. Use of a breaker-failure timer set to about 0.25 seconds would avoid generator tripping for a failure of breaker R to interrupt.

Neutral Element Backup Settings

(1) The 51N element has no relays to coordinate with because the generators are ungrounded. An
instantaneous element, if used, must be set above the maximum false residual current that can be developed due to dissimilar current transformer saturation during an external three-phase fault. Similarly, the time setting of the time overcurrent element must ride through this transient resulting from current transformer saturation.
(2) Ground current contribution from each transformer is 485 amperes. Normal total current level is:
(3) Set the time element for 0.8-ampere pickup. (4) Set the time element (51N) at 0.2 s for 970 amperes primary (see B3 curve):
(5) Set the instantaneous (50N) pickup at 5 amperes:
The maximum ground fault current is:
9137200998 Rev E 61

Specifications

BE1-51/27C Time Overcurrent Relays electrical and physical specifications are described below.

Operational Specifi c a ti ons

Time Overcurrent Pickup Selection Range

Continuously adjustable over the current sensing input ranges specified in the style chart.

Time Overcurrent Measuring Accuracy

±2% of pickup setting. When the TAP CAL control is fully CW, the actual pickup will be within ±5% of the front panel TAP
selector setting.

Time Overcurrent Dropout Ratio

Better than 92% of pickup level.

Instantaneous Overcurrent Pickup Range

Continuously adjustable over the range of 1 to 40 times the time overcurrent pickup setting.

Instantaneous Overcurrent Measuring Accuracy

±2% of pickup setting.

Instantaneous Overcurrent Dropout Ratio

Better than 98% of pickup level.

Instantaneous Response

Figure 38 shows the typical response for the instantaneous pickup element.
Figure 38. Typical Instantaneous Response Time
62 9137200998 Rev E

Time Delay Accuracy

±5% of the characteristic curve for any combination of the front panel TIME DIAL setting and the front panel TAP/TAP CAL overcurrent pickup setting. Refer to the Time Overcurrent Characteristic Curves chapter for more information.
Repeatability is within ±2% of setting at 25°C.

General Specifications

Voltage Sensing Inputs

Rated for 160 Vac continuous at 40 to 70 Hz (nominal frequency 50 or 60 Hz) with a maximum burden of 1 VA.

Voltage Sensing Selection Range

Continuously adjustable over the range of 40 to 120 Vac.

Voltage Sensing Accuracy

±2% of pickup setting.

Sensing Input Burden

Less than 0.1 ohms per phase or neutral.

Sensing Input Rating

The maximum continuous rating is 20 A, 1 second current rating is 50X (times) the maximum tap current selected, or 500 A, whichever is less. For ratings other than those specified by the time curves, the rating is calculated as follows:
50 × 𝑡𝑎𝑝 𝑜𝑟 500 𝐴 (𝑤ℎ𝑖𝑐ℎ𝑒𝑣𝑒𝑟 𝑖𝑠 𝑙𝑒𝑠𝑠
𝐼 =
I = Maximum current T = Time that current flows (in seconds)
𝑇
√
)

Output Circuits

Resistive Ratings
120 Vac ............ Make, break, and carry 7 Aac continuously
250 Vdc ............ Make and carry 30 Adc for 0.2 s, carry 7 Adc continuously, and break 0.3 Adc
500 Vdc ............ Make and carry 15 Adc for 0.2 s, carry 7 Adc continuously, and break 0.3 Adc
Inductive Ratings
120 Vac, 125 Vdc, 250 Vdc........ Break 0.3 A (L/R = 0.04)

Target Indicators

Function targets may be specified as either internally operated or current operated by a minimum of 0.2 amperes through the output trip circuit. When current operated, the output circuit must be limited to 30 amperes for 0.2 seconds, 7 amperes for 2 minutes, and 3 amperes continuously.

Power Supply

Power for the internal circuitry may be derived from a variety of ac or dc external power sources as indicated in Table 5.
9137200998 Rev E 63
Input Voltage
Nominal
Range
O (mid-range)
48 Vdc
24 to 150 Vdc
1.6 W
125 Vdc 120 Vac
24 to 150 Vdc 90 to 132 Vac
1.9 W
8.9 VA
R (low-range)
24 Vdc
12 to 32 Vdc *
1.7 W
48 Vdc
125 Vdc
24 to 150 Vdc 24 to 150 Vdc
1.6 W
1.9 W
250 Vdc 240 Vac
68 to 280 Vdc 90 to 270 Vac
2.1 W
14.2 VA
Table 5. Power Supply Specifications
Type
P (mid-range)
S (mid-range)
T (high-range)
* Type R power supply may require 14 Vdc to begin operation. Once operating, the voltage may be reduced to 12 Vdc.
Burden at Nominal

Radio Frequency Interference (RFI)

Field-tested using a five-watt, hand-held transceiver operating at random frequencies centered around 144 MHz and 440 MHz, with the antenna located six inches from the relay in both horizontal and vertical planes.

Isolation

In accordance with IEC 255-5 and ANSI/IEEE C37.90, 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

Surge Withstand Capability

Qualified to ANSI/IEEE C37.90.1-1989, Standard Surge Withstand Capability (SWC) Tests for Protective Relays and Relay Systems.

UL Recognized

UL recognized per Standard 508, UL File No. E97033. Note: Output contacts are not UL recognized for voltages greater than 250 volts and input power supply voltages greater than 150 volts.

GOST-R

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

Operating Temperature

The operating temperatur e r ange is from −40°C (−40°F) to +70°C (+158°F).

Storage Temperature

The storage temperature range is from −65°C (−85°F) to +100°C (+212°F).

Shock

In standard tests, the relay has withstood 15 g in each of three mutually perpendicular planes without structural damage or degradation of performance.
64 9137200998 Rev E

Vibration

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

Weight

Single-Phase ................................... 13.0 lbs. (5.90 kg)
Two-Phase and Neutral .................. 14.0 lbs. (6.35 kg)
Three-Phase ................................... 14.0 lbs. (6.35 kg)
Three-Phase and Neutral ................ 14.4 lbs. (6.53 kg)

Case Size

S1 (Refer to the Installation chapter for case dimensions.)
9137200998 Rev E 65
Timing Choices
Z1
Z2
Z3 (Integrating)
Short Inverse
Short Inverse
Short Inverse
Long Inverse
Long Inverse
Long Inverse
Definite Time
Definite Time
Definite Time
Moderately Inverse
Moderately Inverse
Moderately Inverse
Inverse Time
Inverse Time
Inverse Time
Very Inverse
Very Inverse
Very Inverse
Extremely Inverse
Extremely Inverse
Extremely Inverse
I2t
BS 142 Long Inverse
I2t
I2t with Limit 1
BS142 Inverse
I2t with Limit 1
I2t with Limit 2
BS142 Inverse
I2t with Limit 2
I2t with Limit 3
BS142 Very Inverse
I2t with Limit 3
I2t with Limit 4
BS142 Extremely Inverse
I2t with Limit 4
I2t with Limit 5
N/A
I2t with Limit 5
I2t with Limit 6
N/A
I2t with Limit 6
I2t with Limit 7
N/A
I2t with Limit 7
I2t with Limit 8
N/A
I2t with Limit 8

Time Overcurrent Characteristic Curves

Graphs on the following pages illustrate sample characteristic curves for all of the time overcurrent functions individually as options, or selectable by switch (if the Z1, Z2, or Z3 timing option is specified). Z1 option can select any of the timing types designated as B1 through B8, and C1 through C8. Z2 option can select any of the timing types designated as B1 through B8, and the British Standard timing types: E2, E4, E5, E6, and E7. Z3 option can select the integrating algorithm for any of the timing types designated as B1 through B8, and C1 through C8.
Note that there are two versions of each timing type: standard and extended timing. Both types are located on the same page. The exception to this is the British Standard curves, which do not have an extended timing version. For any given relay, either the standard or the extended range version will apply, never both.
Table 6 lists timing choices with available curves. Table 7 lists the positions of the timing curve selector switch. (See the Controls and Indicators chapter for switch location).
Table 6. Timing Choices with Available Curves
Available Curves
BE1-51/27C Time Overcurrent Characteristic Curves
66 9137200998 Rev E
Standard
Fig. No.
Extended
Fig. No.
Standard
Fig. No.
Extended
Fig. No.
B1 - Short Inverse
3 3 A-1
A-2
A-38
A-39
B2 - Long Inverse
1 1 A-3
A-4
A-40
A-41
B3 - Definite Time
5 5 A-5
A-6
A-42
A-43
B4 - Moderately Inverse
2 2 A-7
A-8
A-44
A-45
B5 - Inverse
4 4 A-9
A-10
A-46
A-47
B6 - Very Inverse
6 6 A-11
A-12
A-48
A-49
B7 - Extremely Inverse
7 7 A-13
A-14
A-50
A-51
B8 - I2t 0 0
A-15
A-16
A-52
A-53
C1 - I2t with Limit #1
8 — A-17
A-18
A-54
A-55
C2 - I2t with Limit #2
9 — A-19
A-20
A-56
A-57
C3 - I2t with Limit #3
A — A-21
A-22
A-58
A-59
C4 - I2t with Limit #4
B — A-23
A-24
A-60
A-61
C5 - I2t with Limit #5
C — A-25
A-26
A-62
A-63
C6 - I2t with Limit #6
D — A-27
A-28
A-64
A-65
C7 - I2t with Limit #7
E — A-29
A-30
A-66
A-67
C8 - I2t with Limit #8
F — A-31
A-32
A-68
A-69
E2 - Long Inverse
— 8 A-33 — —
—
E4 - Inverse
— 9 A-34 — —
—
E5 - Inverse
— A A-35 — —
—
E6 - Very Inverse
— B A-36 — —
—
E7 - Extremely Inverse
—
C,D,E,F
A-37 — —
—
Table 7. Timing Curve Selection Table
Timing Type
Selector Position
Z1, Z3
Selector Position
Z2
Curves
Z1, Z2
Curves
Z1, Z2
Curves
Z3
Curves
Z3
9137200998 Rev E 67
P0049-02
1.5
P0049-03
1.5
Figure 39. Timing Type B1, Short Inverse
Figure 40. Timing Type B1, Short Inverse with
Extended Timing Range
BE1-51/27C Time Overcurrent Characteristic Curves
68 9137200998 Rev E
P
004
9-04
P0049-05
Figure 41. Timing Type B2, Long Inverse
Figure 42. Timing Type B2, Long Inverse
with Extended Timing Range
9137200998 Rev E 69
P0049-06
P0049-07
Figure 43. Timing Type B3, Definite Time
Figure 44. Timing Type B3, Definite Time with
Extended Timing Range
BE1-51/27C Time Overcurrent Characteristic Curves
70 9137200998 Rev E
P0049-08
P
00
49-09
Figure 45. Timing Type B4, Moderately Inverse
Figure 46. Timing Type B4, Moderately Inverse
with Extended Timing Range
9137200998 Rev E 71
P0049-10
P0049-10
Figure 47. Timing Type B5, Inverse
Figure 48. Timing Type B5, Inverse
with Extended Timing Range
BE1-51/27C Time Overcurrent Characteristic Curves
72 9137200998 Rev E
P0049-12
P0049-13
Figure 49. Timing Type B6, Very Inverse
Figure 50. Timing Type B6, Very Inverse with
Extended Timing Range
9137200998 Rev E 73
P0049-14
P0049-15
Figure 51. Timing Type B7, Extremely Inverse
Figure 52. Timing Type B7, Extremely Inverse with
Extended Timing Range
BE1-51/27C Time Overcurrent Characteristic Curves
74 9137200998 Rev E
P0049-16
P0049-17
Figure 53. Timing Type B8, I2t
Figure 54. Timing Type B8, I2t
with Extended Timing Range
9137200998 Rev E 75
P0049-18
P0
04
9
-1
9
Figure 55. Timing Type C1, I2t with Limit #1
Figure 56. Timing Type C1, I2t with Limit #1 and
Extended Timing Range
BE1-51/27C Time Overcurrent Characteristic Curves
76 9137200998 Rev E
P0049-20
P0049-21
Figure 57. Timing Type C2, I2t with Limit #2
Figure 58. Timing Type C2, I2t with Limit #2 and
Extended Timing Range
9137200998 Rev E 77
P0049-22
P0049-23
Figure 59. Timing Type C3, I2t with Limit #3
Figure 60. Timing Type C3, I2t with Limit #3 and
Extended Timing Range
BE1-51/27C Time Overcurrent Characteristic Curves
78 9137200998 Rev E
P00
49
-
24
P0049-25
Figure 61. Timing Type C4, I2t with Limit #4
Figure 62. Timing Type C4, I2t with Limit #4 and
Extended Timing Range
9137200998 Rev E 79
P0049-26
P
0
04
9-
2
7
Figure 63. Timing Type C5, I2t with Limit #5
Figure 64. Timing Type C5, I2t with Limit #5 and
Extended Timing Range
BE1-51/27C Time Overcurrent Characteristic Curves
80 9137200998 Rev E
P0049-28
P0049-29
Figure 65. Timing Type C6, I2t with Limit #6
Figure 66. Timing Type C6, I2t with Limit #6 and
Extended Timing Range
9137200998 Rev E 81
P
004
9-3
0
P0049-31
Figure 67. Timing Type C7, I2t with Limit #7
Figure 68. Timing Type C7, I2t with Limit #7 and
Extended Timing Range
BE1-51/27C Time Overcurrent Characteristic Curves
82 9137200998 Rev E
P00
49-3
2
P
0
04
9-
3
3
Figure 69. Timing Type C8, I2t with Limit #8
Figure 70. Timing Type C8, I2t with Limit #8 and
Extended Timing Range
9137200998 Rev E 83
P0049-34
P0049-35
Figure 71. Timing Type E2,
BS 142 Long Inverse
Figure 72. Timing Type E4,
BS 142 Inverse
BE1-51/27C Time Overcurrent Characteristic Curves
84 9137200998 Rev E
P0049-36
P0049-37
Figure 73. Timing Type E5,
BS 142 Inverse
Figure 74. Timing Type E6,
BS 142 Very Inverse
9137200998 Rev E 85
P0049-38
P0049-39
Figure 76. Timing Type B1, Short Inverse
with Integrated Algorithm
Figure 75. Timing Type E7,
BS 142 Extremely Inverse
BE1-51/27C Time Overcurrent Characteristic Curves
86 9137200998 Rev E
P0
049-
40
P0049-41
Figure 77. Timing Type B1, Short Inverse with
Integrated Algorithm and Extended Timing
Figure 78. Timing Type B2, Long Inverse
with Integrated Algorithm
9137200998 Rev E 87
P
004
9-42
P0049-43
Figure 79. Timing Type B2, Long Inverse with
Integrated Algorithm and Extended Timing
BE1-51/27C Time Overcurrent Characteristic Curves
Figure 80. Timing Type B3, Definite Time
with Integrated Algorithm
88 9137200998 Rev E
P
0
04
9-
4
4
P0049-45
Figure 81. Timing Type B3, Definite Time with
Integrated Algorithm and Extended Timing
Figure 82. Timing Type B4, Moderately Inverse
with Integrated Algorithm
9137200998 Rev E 89
P0049-46
P0049-47
Figure 83. Timing Type B4, Moderately Inverse
with Integrated Algorithm
and Extended Timing
Figure 84. Timing Type B5, Inverse with Integrated
Algorithm
BE1-51/27C Time Overcurrent Characteristic Curves
90 9137200998 Rev E
P00
49-
48
P0049-49
Figure 85. Timing Type B5, Inverse with Integrated
Algorithm and Extended Timing
Figure 86. Timing Type B6, Very Inverse
with Integrated Algorithm
9137200998 Rev E 91
P
0049
-50
P0049-51
Figure 87. Timing Type B6, Very Inverse with
Integrated Algorithm and Extended Timing
Figure 88. Timing Type B7, Extremely Inverse with
Integrated Algorithm
BE1-51/27C Time Overcurrent Characteristic Curves
92 9137200998 Rev E
P0049-52
P0049-53
Figure 89. Timing Type B7, Extremely Inverse with
Integrated Algorithm
and Extended Timing
Figure 90. Timing Type B8, I2t
with Integrated Algorithm
9137200998 Rev E 93
P0049-54
P0049-55
Figure 91. Timing Type B8, I
Algorithm and Extended Timing
t with Integrated
Figure 92. Timing Type C1, I2t Limit #1
with Integrated Algorithm
2
BE1-51/27C Time Overcurrent Characteristic Curves
94 9137200998 Rev E
P0049-56
P
0
04
9-
5
7
Figure 93. Timing Type C1, I2t Limit #1
with Integrated Algorithm
Figure 94. Timing Type C2, I2t Limit #2
with Integrated Algorithm
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