GEI-50261K INSTRUCTIONS RELAY VOLTAGE UNBALANCE TYPE NBVllA CONTENTS INTRODUCTION APPLICATION CHARACTERISTICS RATINGS CALCULATIONS CONSTRUCTION RECEIVING, HANDLING & STORAGE ACCEPTANCE TESTS INSTALLATION PROCEDURE PERIODIC CHECKS ROUTINE MAINTENANCE RENEWAL PARTS GE Protection and Control Great Valley Parkway 19355-1337 Malvern, PA...
GEI-50261 URBALANCE RELAY VOLTAGE NBVllA TYPE INTRODUCTION The NBV1 1A relay is a high-speed sensitive three-phase voltage unbalance relay that is capable of detecting a small voltage unbalance in a three-phase system. NBV 1 1A, when applied as a protective device, is normally used in con unction with a time-delay relay such as the IAV5 1D relay shown in Figure 12.
GEI-50261 The negative-sequence voltage will be proportional to the unbalance in the line voltages. When balanced three-phase voltage correct phase sequence connected to the relay studs 5, 6 and 7, as shown in Figure 8, then the voltage across the relay coil, TR, which is proportional to the negative-sequence voltage, will be zero.
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GEI-50261 TABLE I I N TERRUPTI N G RATI N GS I N DUCTIVE * N O N -I N DUCTIVE 0. 75 2. 0 0. 5 1. 5 DC VOLTS 1. 0 3. 0 0. 5 1. 5 0. 25 1.
GEI-50261 TABLE IV CURRE N T (AMPS) FREQUE N CY VOLTS VOLT - AMPS 0.1 14 13.68 0.995 1 1.40 0.056 11.60 CALCULATIONS In order to demonstrate how the V R pickup voltage, as defined 1-n the section on is related to the negative phase-sequence voltage, we will first CHARACTERISTICS, show how the negative phase sequence is computed.
GEI-50261 triangle as shown in Figure 9 (b). In this illustration Vg represents the voltage unbalance of the line voltages. The Vg voltage in this case will be equal to and therefore at pickup: For example, if we wish the relay to pick up when the unbalance represented by Vg is volts, then we set the relay to pick up when a single-phase voltage of volts is applied, shown in Figure...
GEI-50261 Reasonable care should be exercised in unpacking the relay in order that none of the parts are in jured nor the ad justments disturbed. If the relays are not to be installed immediately, they should be stored in their original cartons in a place that is free from moisture, dust and metallic chips.
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GEI-50261 N ote: If a suitable three-phase source of rated voltage is not available, For example, a volt relay may a good wave shape and rated frequency. If this is done, the voltage observed across volts . be tested at should be proportionally lower.
GEI-50261 The harmonic filter models available are: 60 hertz 016SA6788Gl 016SA6788G2 SO hertz Only one filter is required for each N BV relay. The filter is mo�nted as shown in Figure 14 and connected across terminals 3-4 of the N BV relay, as shown in Figure 12.
Sales Office of General Electric Company. Specify the name of the part wanted, quantity required, complete nameplate data (including the serial number) of the relay, and if possible the GE requisition number on which the relay was furnished.
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GEI-50261 COVER (8024451) TYPE NBV11A Relay, Front View Figure (8031805) Type NBV11A Relay - Top View Showing Location of Parts Referred to in Text Figure (8031804) Type NBVllA Relay Left Side View Figure (8031803) Type NBV11A Relay Oblique Rear View Figure (0459A0251) Operating Times of Type NBV11A Relay Contacts When...
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GEI-50261 �t4 :��: :tt; " ('(\ '<:t SONOJ3Silll� Nl 3�11 Operating Times of Type N BVllA Relay Contacts Figure 4 (0459A0251) When Unbalanced Voltage Is Suddenly Applied...
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GEI-50261 ¢1 RATED VOLTAGE � t> l & FREQUENCY ¢2 ¢2 ¢3 -----·-- ¢3 Figure 7 (0418A0807-2) Test Connections for Checking R-C Circuit Adj ustment...
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GEI-50261 AUTo TRANSFORMER t� ¥. SHORT I NGER fl{j Internal Connections for Type N BVllA Relay (Front View) Figure 8 (0418A0805 )
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GEI-50261 115V COAITI!VVITY LIGHT (W/7H VOLTA(#� SOVI"CI) VARIAC Figure 10 (0459A0223-2) Test Connections for Setting Pickup of Type NBV11A Relay...
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GEI-50261 CONNECTING PLUG AUXI LIARY S HORTING NOTE: AF TER ENGA GING AUXILIARY B R USH, CONNECTING PLUG TRAVE LS INCH BEFORE ENGAGING THE MAIN BRUSH ON THE TERMINAL B LOCK (8025039) Figure Cross Section of Drawout Case Showing Position of Auxiliary Brush...
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GEI-50261 PIASE SEQUEIC£ 1- 2 -1 FUSES POWER TRANSFORMER IF U.f£D IF USED AUX. PT' S P T . I : I USE fiTHER --+3 RATIO PT'S AS SfiOWII r - -, Y.--1 -, 62 /'· " � ..__ _ J r--, -...