Basler Electric BE1-81O-U User Manual

INSTRUCTION MANUA L

FOR

BE1-81O/U

Digital Frequency Relay

Publication: 9137300990 Revision: N Jun-14

9137300990 Rev N i

Caution

Note

Preface

This instruction manual provides information about the installation and operation of the BE1-81O/U Digital Frequency Relay. To accomplish this, the following information is provided:

• General information

• Controls and indicators

• Functional description

• Installation

• Testing

• 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.

BE1-81O/U Preface

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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

and options are subject to modification without notice. Over time, improvements and revisions may be made to this manual.

The English-language version of this manual serves as the only approved 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

First printing: June 1982

Warning!

READ THIS MANUAL. Read this manual before installing, operating, or maintaining the BE1-81O/U.

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 details and variations in equipment, nor does this manual provide data for every possible contingency regarding installation or operation. The availability and design of all features

publication. Before performing any of the following procedures, contact Basler Electric for the latest revision of this

Preface BE1-81O/U

9137300990 Rev N iii

Introduction ................................................................................................................................................. 1

Features .................................................................................................................................................... 1

Frequency Setpoints .............................................................................................................................. 1

Time Delays ........................................................................................................................................... 1

Undervoltage Inhibit ............................................................................................................................... 1

Targets ................................................................................................................................................... 1

Operation ................................................................................................................................................... 1

Style Number ............................................................................................................................................. 1

Controls and Indicators .............................................................................................................................. 3

Front Panel ................................................................................................................................................ 3

Circuit Board .............................................................................................................................................. 4

Multiplier Settings ................................................................................................................................... 4

Cycles/Seconds Settings ....................................................................................................................... 4

Functional Description ............................................................................................................................... 7

Input Signal ................................................................................................................................................ 7

Undervoltage Inhibit ................................................................................................................................... 7

Zero-Crossing Logic .................................................................................................................................. 7

Crystal Oscillator ....................................................................................................................................... 7

Period Clock Generator ............................................................................................................................. 7

Minimum Period Difference Logic ............................................................................................................. 7

Maximum Period Difference Logic ............................................................................................................ 9

Measured Frequency Converter ................................................................................................................ 9

Frequency Comparator Logic .................................................................................................................... 9

Definite Time Delay Logic.......................................................................................................................... 9

Time Delay Selection ........................................................................................................................... 10

Relay Outputs .......................................................................................................................................... 11

Auxiliary Relay Outputs ........................................................................................................................... 11

Power Supply .......................................................................................................................................... 11

Power Supply Status Output ................................................................................................................... 11

Target Indicators ...................................................................................................................................... 11

Internally Operated Targets ................................................................................................................. 11

Current Operated Targets .................................................................................................................... 11

Installation ................................................................................................................................................. 13

Operating Precautions ............................................................................................................................. 13

Mounting .................................................................................................................................................. 13

Connections ............................................................................................................................................. 33

Maintenance ............................................................................................................................................ 35

Storage .................................................................................................................................................... 35

Testing ........................................................................................................................................................ 37

Test Equipment ....................................................................................................................................... 37

Operational Test ...................................................................................................................................... 37

High and Low Frequency Pickup ......................................................................................................... 37

Frequency Selector Settings ................................................................................................................ 38

Definite Time Delay – Cycles ............................................................................................................... 39

Definite Time Delay – Seconds ........................................................................................................... 39

Undervoltage Inhibit ............................................................................................................................. 40

Setpoint 2, 3, and 4 Testing ................................................................................................................. 40

Specifications ............................................................................................................................................ 41

Sensing Input ....................................................................................................................................... 41

Operating Power Input ......................................................................................................................... 41

Relay Outputs ...................................................................................................................................... 41

Output Contacts ................................................................................................................................... 41

Target Indicators (Optional) ................................................................................................................. 41

BE1-81O/U Contents

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Frequency Setpoint .............................................................................................................................. 42

Time Delay ........................................................................................................................................... 42

Undervoltage Inhibit ............................................................................................................................. 42

Type Tests ........................................................................................................................................... 42

Temperature Ratings ........................................................................................................................... 43

UL Recognized .................................................................................................................................... 43

GOST-R ............................................................................................................................................... 43

Case Size ............................................................................................................................................. 43

Weight .................................................................................................................................................. 43

Revision History ........................................................................................................................................ 45

Contents BE1-81O/U

9137300990 Rev N 1

Introduction

The BE1-81O/U Digital Frequency Relay monitors the frequency of a single-phase, ac voltage and provides accurate frequency protection for a distribution system or generator operating at 50 or 60 hertz.

The BE1-81O/U initiates removal of a load from a distribution system when the system frequency decreases below the relay’s adjustable setpoint. When the system frequency returns to normal (as defined by another setpoint), the BE1-81O/U permits restoration of the load. The BE1-81O/U may be tailored to the operating frequency/time characteristic of a generator to permit removal of the generator from service if the generator frequency (or system frequency) exceeds a setpoint. This scheme also permits restoration to service when the generator (or system) frequency returns to normal.

Features

The BE1-81O/U can be specified with up to four independently adjustable frequency setpoints and time delays with associated output relays and target indicators.

Frequency Setpoints

Each frequency setpoint has a setting range of 40 to 70 hertz and can be switch-selected to detect overfrequency or underfrequency. BE1-81O/U relays with one or two setpoints are supplied in an S1 case. Relays with three or four setpoints are supplied in an M1 case.

Time Delays

Each definite time delay setting can be adjusted for a delay of three cycles to 990 seconds.

Undervoltage Inhibit

An undervoltage inhibit feature prevents relay operation if the sensed voltage decreases below the adjustable front-panel setting.

Targets

Either internally-operated or current-operated target indicators are available for each setpoint.

Operation

When the sensed frequency passes through a setpoint in the selected direction, a three-cycle timer begins timing. If the condition persists for the duration of the three-cycle timer, the Pickup LED indicator lights and the definite time delay is triggered. If the pickup condition persists for the duration of the Time Delay setting, the corresponding output relay energizes, operates the appropriate output contacts, and trips the setpoint’s target indicator.

Style Number

BE1-81O/U electrical characteristics and operating features are defined by a combination of letters and numbers that make up the relay style number. The style number describes the features and options of a particular relay and appears on the front panel, draw-out cradle assembly, and the relay case. The style number identification chart shown in Figure 1

illustrates the features and options for the BE1-81O/U relay.

BE1-81O/U Introduction

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Figure 1. Style Chart

Introduction BE1-81O/U

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Locator

Function

Undervoltage Inhibit Indicator. This light emitting diode (LED) lights when the sensed inhibited when this LED is on.

Undervoltage Inhibit Control. Relay operation is inhibited when the sensed voltage

set at 80 Vac.

Controls and Indicators

BE1-81O/U controls and indicators are located on the front panel and circuit boards.

Front Panel

The front-panel control and indicators are shown in Figure 2 and described in Table 1.

Figure 2. Front-Panel Controls and Indicators

Table 1. Front-Panel Controls and Indicators

voltage decreases below the setting of the Undervoltage Inhibit Control. Relay operation is

decreases below the setting of this multi-turn potentiometer. The Undervoltage Inhibit Control has a setting range of 40 to 120 Vac. The BE1-81O/U is delivered with the control

BE1-81O/U Controls and Indicators

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Locator

Function

Time Delay Selector Switches . A set of two thumbwheel switches sets the time delay

provided for each frequency setpoint of the relay.

Pickup Indicator. When an underfrequency or overfrequency condition is detected, the level.

Power Indicator. This LED lights when operating power is applied to the relay.

Target Reset Switch. Operating this switch resets all of the target indicators.

Target Indicators. Electronically-latching red target indicators illuminate when the associated

operated targets, the trip circuit current must be greater than 200 milliamperes.

Frequency Selector Switches. A set of four thumbwheel switches adjusts the setpoint

protection.

Over/Under Selector Switch. A two-position toggle switch configures the corresponding selector switch is provided for each frequency setpoint of the relay.

between the corresponding frequency setpoint (locator H) pickup and output re lay r eact ion. The time delay obtained by these switches is affected by the setting of Selector Switch S7. See Circuit Board for details about configuring S7. One set of two thumbwheel switches is

corresponding pickup indicator lights and stays lit until the frequency returns to a non-trip

setpoint output relay energizes. When the optional targets are specified, a target indicator is provided for each frequency setpoint of the relay. To ensure proper operation of current-

frequency in 0.01 hertz increments over an allowable range of 40 to 70 hertz. One set of four thumbwheel switches is provided for each frequency setpoint of the relay. Note that selecting a setting outside the 40 to 70 hertz range will result in a loss of frequency

frequency setting (locator H) as an overfrequency (O) or underfrequency (U) setpoint. One

Circuit Board

A single control, Selector Switch S7, is located on the Definite Time circuit boards. (The number of Definite Time circuit boards corresponds to the number of setpoints specified by the relay style number.) S7 configures the Time Delay Selector Switches (Table 1, locator C) to adjust the definite time delay in seconds or cycles and have a multiplier of times 1, 10, or 100.

With the cradle assembly withdrawn from the case, the three-section Selector Switches are accessed at the right side of the cradle assembly. Figure 3 illustrates the location of S7 on a BE1-81O/U relay with two setpoints.

Multiplier Settings

A times 10 multiplier is also obtained when S7-1 is placed in the down position and S7-2 is placed in the up position.

For a times 100 (X100) multiplier, S7-1 and S7-2 are placed in the up position.

Cycles/Seconds Settings

S7-3 either selects cycles or seconds as the unit of measure for the definite time delay. S7-3 is placed in the up position to select cycles. The down position of S7-3 selects seconds.

Controls and Indicators BE1-81O/U

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Figure 3. Location of Selector Switch S7

BE1-81O/U Controls and Indicators

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Controls and Indicators BE1-81O/U

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Functional Description

The BE1-81O/U has one to four frequency setpoints for protecting an ac source from underfrequency and overfrequency conditions within the limits of 40 to 70 hertz. When the BE1-81O/U senses an underfrequency or overfrequency condition, an output relay energizes after a selectable time delay. Relay operation is disabled if the sensed voltage decreases below an adjustable undervoltage inhibit setting.

BE1-81O/U functions are illustrated in the block diagram of Figure 4 and described in the following paragraphs.

Input Signal

Because input signal crossings are used to measure the input frequency, it is necessary to filter unwanted harmonics and transients. Some attenuation of the input signal results. Figure 5 shows the attenuation, in decibels, for input frequencies of 12 to 200 Hz.

A single-phase voltage is applied to an input signal conditioning circuit that consists of a transformer and band-pass filter. The sensed input signal is applied to the zero-crossing logic and undervoltage detection circuits.

Undervoltage Inhibit

This circuit prevents the output relays from energizing during an undervoltage condition associated with equipment startup. The circuit prevents operation of the zero-cross logic and time delay logic, and lights the Undervoltage Inhibit Indicator when the level of the sensed voltage decreases below the setting. A potentiometer, accessed through the front panel, is used to adjust the undervoltage inhibit level from 40 to 120 Vac. BE1-81O/U relays are delivered with an undervoltage inhibit setting of 80 Vac.

Zero-Crossing Logic

The zero-crossing logic circuit converts the sensed frequency to pulses synchronized to each positivegoing zero crossing of the waveform. The pulse frequency represents the period of the waveform and is applied to the period clock generator, minimum period difference logic, and maximum period difference logic circuits.

Crystal Oscillator

The crystal-controlled oscillator provides accurate 1 MHz and 2 MHz timing signals for the clock logic.

Period Clock Generator

A frequency comparison is made for each cycle of sensed frequency. The period clock generator supplies a reference signal that is synchronized with the beginning of each cycle of the sensed frequency. At each zero-crossing pulse, the clock gates the 2 MHz period clock pulses to the minimum period difference logic circuit.

Minimum Period Difference Logic

Each zero-cross pulse causes this logic to count 24,580 2 MHz clock pulses, which is the period of the 80 hertz maximum detectable frequency limit. When the sensed frequency is less than the limit, an end-ofperiod reference (EOPR) pulse is generated to initiate the maximum period difference and measurement logic.

BE1-81O/U Functional Description

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However, if the sensed frequency equals or exceeds the 80 hertz maximum frequency limit (zero-cross pulses interrupt the counts) for three consecutive cycles, the maximum period difference logic is bypassed. The measured-frequency converter then computes the frequency at this maximum frequency limit. The definite time delay is not affected by the frequency limit being exceeded.

Figure 4. BE1-81O/U Functional Block Diagram

Functional Description BE1-81O/U

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Frequency (HZ)

12 40 60 80 100 120 140 160 180 200

D2856-24

Figure 5. Band-Pass Filter Characteristics

Maximum Period Difference Logic

This logic includes an address resister and programmable, read-only memory (PROM). Following the EOPR pulse from the minimum period difference logic, the address register counts 1 MHz clock pulses to address 4,096 data words stored in the PROM. Completion of the count represents the period of the 30 Hz minimum detectable frequency limit. If zero-cross pulses have properly occurred before the count ends, the measured frequency converter computes the actual frequency, within the frequency limits, utilizing the corresponding data words stored in the PROM.

If sensed frequency decreases to less than the 30 Hz minimum frequency limit (zero-cross pulses occur after the counts are completed) for three consecutive cycles, the measured frequency converter computes the frequency at the minimum frequency limit. The definite time delay is not affected by the frequency limit being exceeded.

Measured Frequency Converter

The measured frequency converter changes the data word from the maximum period difference logic to a four-digit, binary-coded decimal (BCD) number that represents the actual sensed frequency (with an accuracy of 0.01 Hz) within the 30 to 80 Hz limits. The BCD frequency data bus passes this data to the frequency comparator logic of each setpoint.

Frequency Comparator Logic

This logic compares the BCD number representing the actual sensed frequency with the Frequency Selector Switch setting on the front panel. An output is triggered when the sensed frequency decreases below the setpoint (Over/Under Selector Switch set to U), or when the sensed frequency increases above the setpoint (Over/Under Selector Switch set to O). The resultant output consists of an enabling level that starts a count-up timer and lights the front panel Pickup Indicator.

Definite Time Delay Logic

The enable signal (representing a detected over or underfrequency condition) from the frequency comparator logic initiates the count of zero-cross pulses. After three consecutive cycles exceed the pickup setting, the definite time delay logic lights the Pickup Indicator. When the front-panel Time Delay

BE1-81O/U Functional Description

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Note

Time Delay

Selector Switch

Selector Switch S7

S7-1, 2

S7-3

Cycles

25 cycles

X10

Cycles

250 cycles

X100

Cycles

2,500 cycles

Seconds

2.5 seconds

X10

Seconds

25 seconds

X100

Seconds

250 seconds

Selector Switch setting is reached, the logic energizes the setpoint output relay. The total time delay, with seconds-type timing selected, is the Time Delay Selector Switch setting plus one cycle of the sensed input plus 0.008 seconds (output relay delay). The Pickup LED remains lit until the frequency condition is corrected. When the sensed frequency returns to normal for three cycles, the Pickup LED and output relay reset.

When delay is set in cycles, the relay calculates delay using a zero-cross counter. Hence, the measured delay will vary with incoming frequency. The time delay may be calculated as follows.

𝑑𝑒𝑙𝑎𝑦 (𝑠𝑒𝑐𝑜𝑛𝑑𝑠 =

If 00, 01, or 02 is set as the time delay, the relay response will vary according to the revision level of the relay. The revision-dependent response of the relay may include a block of relay tripping, a trip as fast as two cycles, or a trip in three or more cycles.

A delay setting of 00, 01, or 02 cycles should not be used unless the relay response to the setting is tested and found acceptable.

When delay is set in seconds, the relay calculates delay using an internal clock. This gives a time delay that will not change as the sensed frequency changes.

𝑑𝑒𝑙𝑎𝑦 𝑠𝑒𝑡𝑡𝑖𝑛𝑔 𝑖𝑛 𝑐𝑦𝑐𝑙𝑒𝑠

𝑎𝑝𝑝𝑙𝑖𝑒𝑑 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 𝑖𝑛 ℎ𝑒𝑟𝑡𝑧

×(± 𝑠𝑝𝑒𝑐𝑖𝑓𝑖𝑐𝑎𝑡𝑖𝑜𝑛 𝑎𝑐𝑐𝑢𝑟𝑎𝑐𝑦

)

Time Delay Selection

Time delay selection is controlled by Selector Switch S7 on the definite time circuit board. S7 is a usersettable, three-section switch for selecting definite timing in seconds or cycles and a multiplier of times 1, 10, or 100.

Earlier BE1-81O/U relays with timing option E1 had a timing range of 3 to 99 cycles and did not include Selector Switch S7. Earlier relays with timing option E2 had a timing range of 3 to 99 cycles.

To provide rearward compatibility for users of earlier BE1-81O/U relays with timing option E1, relays are delivered with S7 set to emulate the E1 timing range.

Sections S7-1 and S7-2 configure the multiplier used with the Time Delay Selector Switches. For a times one (X1) multiplier, S7-1 and S7-2 are placed in the down position. For a times 10 (X10) multiplier, S7-1 is placed in the up position and S7-2 is placed in the down position. A times 10 multiplier is also obtained when S7-1 is placed in the down position and S7-2 is placed in the up position. For a times 100 (X100) multiplier, S7-1 and S7-2 are placed in the up position.

Section S7-3 either selects cycles or seconds as the unit of measure for the definite time delay. S7-3 is placed in the up position to select cycles. The down position of S7-3 selects seconds.

Table 2 lists some time delay setting examples.

Table 2. Time Delay Setting Examples

Functional Description BE1-81O/U

Time Delay

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Relay Outputs

The time delay logic output for each setpoint energizes an associated output relay that is normally open (output type E) or normally closed (output type G). The relay output type specified is the same for each setpoint included in the relay.

Auxiliary Relay Outputs

An auxiliary relay may be specified that is energized simultaneously with the output relay. The relay contacts are either normally open (option 3-1) or normally closed (option 3-2). When specified, this option is included for each setpoint and is the same contact type for all setpoints within a relay.

Power Supply

BE1-81O/U internal circuitry is powered by one of three wide-range power supplies. Power supply voltage ratings are listed in the Specifications chapter.

Relay operating power is developed by the wide-range, isolated, low-burden, flyback-switching power supply. Input power (source voltage) for the power supply is not polarity sensitive. The front-panel Power Indicator lights to indicate that the power supply is functioning properly.

Power Supply Status Output

The optional power supply status output relay (option 2-S) has a set of normally closed contacts that are energized open during normal operation. If the power supply output fails (or operating power is removed from the relay), the power supply status output relay de-energizes and the contacts close.

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.

BE1-81O/U Functional Description

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