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INTRODUCTION This manual provides information concerning the operation and installation of the BE1-87G Variable Percentage Differential Relay. To accomplish this, the following is provided. Specifications Functional description Mounting information Setting procedure/example. WARNING! To avoid personal injury or equipment damage, only qualified personnel should perform the procedures presented in this manual.
First Printing: December 1985 Printed in USA © 1995, 1996, 1999, Basler Electric Co., Highland, IL 62249 May 1999 CONFIDENTIAL INFORMATION OF BASLER ELECTRIC COMPANY, HIGHLAND, IL. IT IS LOANED FOR CONFIDENTIAL USE, SUBJECT TO RETURN ON REQUEST, AND WITH THE MUTUAL UNDERSTANDING THAT IT WILL NOT BE USED IN ANY MANNER DETRIMENTAL TO THE INTEREST OF BASLER ELECTRIC COMPANY.
CONTENTS SECTION 1 GENERAL INFORMATION Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Variable Restraint Characteristic . . . . . . . . . . . . . . . . . . . . . . . . . . Design Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Model and Style Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CONTENTS - Continued SECTION 5 TESTING AND SETTING - Continued Sensing Input Range 1, Operating Characteristics . . . . . . . . . . . . Sensing Input Range 2, Operating Characteristics . . . . . . . . . . . . Extended Restraint Operating Characteristic . . . . . . . . . . . . . . . . . . . Pickup Response Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Phases B And C, Trip And Dropout Test . . . . . . . . . . . . . . . . . . . Target Test . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 1 • GENERAL INFORMATION DESCRIPTION BE1-87G Variable Percentage Differential relays are single- or three-phase solid state devices designed to provide selective, high-speed, differential protection for generators, motors and shunt reactors. Differential relaying selectivity is based on the ability of a relay to distinguish between an internal fault (within the protected zone) and an external fault.
Figure 1-1. Typical Single-Phase Application Scheme Figure 1-2.
Variable Restraint Characteristic At high current levels, the inevitable difference in the saturation characteristics between current transformers indicates a need for a compensating decrease in relay sensitivity. The design of the BE1-87G provides a restraint factor that is proportional to input current when the restraining current (I R) is greater than nominal (five amperes for sensing input type one or one ampere for sensing input type two).
BE1-87G G 1 E A1 J A 0 C 0 F Model Number Three-phase sensing input Sensing range switch selectable for 0.1, 0.15, 0.2, 0.4, 0.5, 0.8, or 1.
SPECIFICATIONS BE1-87G relays are available in single-phase and three-phase configurations, and with the following features and capabilities. Current Sensing Inputs (5 Ampere) (1 Ampere) Current Sensing Burden (5 Ampere) (1 Ampere) Stabilizing Reactor I 2 t Rating (5 Ampere) (1 Ampere) Pickup Control (5 Ampere) Nominally rated at 5 amperes, with a range of 45 to 65 hertz. Maximum current per input: 10 amperes continuous, 250 amperes for 1 second.
Pickup Accuracy (1 Ampere) For I R 1 ampere, ±5% of the operate pickup characteristic or 25 milliamperes whichever is greater. Actual operating characteristics are shown in graph format in Section 5, Testing And Setting the relay. For I R 1 amperes, up to a maximum of 4 amperes, ±8% of the operate pickup characteristic or 150 milliamperes, whichever is greater.
Isolation In accordance with ANSI/IEEE C37.90, one minute dielectric (high potential) tests as follows: All circuits to ground: Input to output circuits: 2121 Vdc 1500 Vac or 2121 Vdc Surge Withstand Capability Qualified to ANSI/IEEE C37.90.1-1989 Standard Surge Withstand Capability (SWC) Tests for Protective Relays and Relay Systems. Fast Transient Qualified to ANSI/IEEE C37.90.1-1989. Impulse Test Qualified to IEC 255-5.
SECTION 2 • HUMAN MACHINE INTERFACE (Controls And Indicators) DESCRIPTION Table 2-1 lists and briefly describes the BE1-87G Variable Percentage Differential Relay operator controls and indicators. Reference the call-out letters to Figure 2-1. Table 2-1. BE1-87G Controls and Indicators (Refer to Figure 2-1) Locator Control or Indicator Function A Sensitivity Switch Establishes reference for the operating current. It is a seven position thumbwheel switch labeled A through G.
SECTION 3 • FUNCTIONAL DESCRIPTION GENERAL BE1-87G Variable Percentage Differential Relays are static devices that protect motors and generators by providing an output signal when incoming current does not match outgoing current by a predetermined but variable limit. The functional block diagram in Figure 3-1 illustrates the overall operation of the BE1-87G Variable Percentage Differential Relay. Note that it may be configured to monitor either single-phase or threephase.
and one ampere nominal), one transformer on each side of the protected machine, supply sensing current for each monitored phase. The sensing currents are applied to the respective input transformers of the relay which provide system isolation and determine the differential and sum currents. These CTs are gapped to withstand DC offset. Stabilizing Reactor To minimize dissimilar performance of the system CTs, the stabilizing reactor acts as a stabilizing impedance during external faults.
Figure 3-3. Sensing Input Range 2 (1 Ampere),Stabilizing Reactor Impedance Characteristics Bandpass Filters Outputs from the relay transformers are filtered to eliminate the third harmonic and to minimize the effect of DC offset caused by CT saturation (as may occur during synchronization or asymmetrical faults). The output of the difference bandpass filter is applied to a full wave rectifier.
supply status output relay continually energized and its output contacts open. If the power supply output voltage falls below the requirements for proper operation, the power supply status output relay de-energizes, closing the NC output contacts. Power Supply Basler Electric enhanced the power supply design for unit case relays. This new design created three, wide range power supplies that replace the five previous power supplies.
SECTION 4 • INSTALLATION GENERAL When not shipped as part of a control or switchgear panel, the relays are shipped in sturdy cartons to prevent damage during transit. Immediately upon receipt of a relay, check the model and style number against the requisition and packing list to see that they agree. Visually inspect the relay for damage that may have occurred during shipment.
Figure 4-2. S1 Case, Double-Ended, Outline Dimensions, Semi-Flush Mounting, Side View Figure 4-3.
Figure 4-4. S1 Case, Double-Ended, Panel Drilling Diagram, Semi-Flush Mounting Figure 4-5.
Stabilizing Reactor The stabilizing reactor for a three-phase relay is mounted on the rear of the relay. For projection mounting or convenience, the stabilizing reactor can be removed and relocated. Rewire in accordance with the procedures and illustrations in this section. To remove the stabilizing reactor, remove four screws holding the reactor to the mounting plate. To remove the mounting plate, remove two five-sixteenths by eighteen, hex head bolts.
Figure 4-7. S1 Case And Reactor, Outline Dimensions (Semi-Flush Mounting) CONNECTIONS Incorrect wiring may result in damage to the relay. Be sure to check model and style number against the options listed in the Style Number Identification Chart before connecting and energizing a particular relay. WARNING Relays manufactured prior to July 22, 1991 (EIA date code symbol 9129 and previous) do NOT have case jumpers between terminals 7 and 8 (single phase units).
Figure 4-8. Typical DC Control Connections Figure 4-9.
Figure 4-10.
Figure 4-11.
Figure 4-12.
SECTION 5 • TESTING AND SETTING GENERAL Proper operation of the relay may be confirmed by performing the operational test procedures in this Section. In the event the relay is not to be installed immediately, store the relay in its original shipping carton in a moisture and dust free environment. RELAY OPERATING PRECAUTIONS Before installation or operation of the relay, note the following precautions: 1. A minimum of 0.
OPERATIONAL TEST PROCEDURE The following procedure verifies operation of the relay. Terminal numbers are referenced to the operational test setup in Figure 5-1. Three-phase units may be tested one phase at a time because all phases are OR'd together at the output. WARNING During testing, do NOT apply or generate continuous operate current greater than three amperes. If the operate current is greater than three amperes, a temperature increase in the reactor may result and cause insulation breakdown.
Figure 5-2. Location of Assemblies (Single Phase Only) NON-COMPONENT SIDE OF LOWER MAGNETICS/SHIELD BOARD Figure 5-3.
Single-Phase Trip And Dropout Test Step 1. Connect the test setup for phase A in accordance with Figure 5-1. Step 2. Set the sensitivity switch to A. Step 3. Apply appropriate power input voltage to terminals 3 and 4. Step 4. Using a regulated current source that is independently adjustable, apply the restraint current (0.1 ampere, sensing input range 1 or 0.02 ampere, sensing input range 2) to phase A terminals 6 and 9. Step 5.
Figure 5-4.
Figure 5-5.
20 RESTRAINT CURRENT (AMPERES) 18 16 14 12 10 8 6 4 2 0 Range 1 0 5 10 15 20 25 30 35 40 Range 2 0 1 2 3 4 5 6 7 8 D2354-14 04-30-96 RESTRAINT CURRENT (AMPERES) Figure 5-6. Extended Restraint Operating Characteristic 45 RESPONSE TIME (MSEC) 40 35 30 25 20 15 0 10 20 30 40 50 60 70 80 90 MULTIPLES OF PICKUP Figure 5-7.
Phases B And C, Trip And Dropout Test Step 1. If the relay is a 3-phase relay, repeat steps 1 through 7 for phases B and C. Target Test If relay is equipped with targets, check for correct operation of each phase when relay is tripped, and for manual reset. NOTE If option B (current operated) targets are specified, the target is only operable when a minimum of 0.2 ampere is present in the output circuit (terminals 1 and 10).
Terms for Calculations I"d Subtransient current N Total number of CT turns Na Number of CT turns in use (for multi-ratio type) Rl One-way lead resistance, in ohms Rr Relay restraint circuit resistance, in ohms Rw CT winding resistance, in ohms. NOTE Sensing Input Range 1: If R w is unknown, assume R w = 0.003 * N a Sensing Input Range 2: If R w is unknown, assume R w = 0.
Table 5-1. Recommended Pickup Settings Vce (Lower Value) SFR 1 1.5 2 3 4 20 0.2 0.4 0.5 0.8 1.6 50 0.2 0.4 0.4 0.5 0.8 100 0.2 0.2 0.4 0.4 0.5 200 0.1 0.1 0.2 0.4 0.5 >200 0.1 0.1 0.2 0.4 0.5 Note: Use next higher setting if CTs are a mix of C classification and T classification. The saturation factor ratio, SFR, represents an index of the relative performance of the two sets of CTs.
Inequality (1) is met with CT #2, but not with CT #1. However, since the locked rotor current is only 4.8 times CT rating [vs. the assumption of 20 times rated for inequality (1)], the application is suitable. SFR = (100/50)*(0.36/0.19) = 3.8 Using the SFR 4 column of Table 5-1, a 0.8 ampere setting is indicated. However, based on the note accompanying this table, choose the next higher setting of 1.6, because CT #1 has a T classification, and CT #2 has a C classification.
Inequality (1) is met with CT #2, but not with CT #1. However, since the maximum external fault current is only 4.6 times CT rating [vs. the assumption of 20 times rated for inequality (1)], the application is suitable. SFR = (100/50)*(0.36/0.19) = 3.8 Using the SFR 4 column of Table 5-1, a 0.8 ampere setting is indicated. However, based on the note accompanying this table, choose the next higher setting of 1.6, because CT #1 has a T classification, and CT #2 has a C classification.
SECTION 6 • MAINTENANCE GENERAL BE1-87G Variable Percentage Differential Relays require no preventive maintenance other than a periodic operational test (refer to Section 5 for the operational test procedures). If factory repair is desired, contact the Customer Service Department of the Power Systems Group, Basler Electric, for a return authorization number prior to shipping.
SECTION 7 • MANUAL CHANGE INFORMATION SUMMARY AND CROSS REFERENCE GUIDE This section contains information concerning the previous editions of the manual. The substantive changes to date are summarized in Table 7-1. Table 7-1. BE1-87G Changes Revision Summary Of Changes ECA/ECO/Date A Added qualifications to specifications listing, revised isolation test and dielectric test.
