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GEI-50261K 

INSTRUCTIONS 

VOLTAGE  UNBALANCE 

RELAY 

CONTENTS 

INTRODUCTION 

APPLICATION 

CHARACTERISTICS 

RATINGS 

CALCULATIONS 

CONSTRUCTION 

RECEIVING,  HANDLING 

STORAGE 

ACCEPTANCE  TESTS 

INSTALLATION  PROCEDURE 

10 

PERIODIC  CHECKS 

AND 

ROUTINE  MAINTENANCE 

10 

RENEWAL  PARTS 

11 

TYPE  NBVllA 

GE Protection and Control 

205 

Great Valley Parkway 

Malvern, PA 

19355-1337 

www 

. ElectricalPartManuals 

. com 

Summary of Contents for 12NBV11A1A

Page 1: ...INGS 4 CALCULATIONS 6 CONSTRUCTION 7 RECEIVING HANDLING STORAGE 7 ACCEPTANCE TESTS 8 INSTALLATION PROCEDURE 10 PERIODIC CHECKS AND ROUTINE MAINTENANCE 10 RENEWAL PARTS 11 TYPE NBVllA GE Protection and Control 205 Great Valley Parkway Malvern PA 19355 1337 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 2: ...BV11A Relay Top View Showing Location of Parts Referred to in Text TELEPHONE RELAY RESISTOR Rl RESISTOR R2 DIODE RECTIFIER BRIDGE Figure 2 8031804 Type NBVl1A Relay Left Side View Figure 3 8031803 Type NBV11A Relay Oblique Rear View 2 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 3: ...e phase condition on light load as well as on heavy load The NBV is usually connected to a bus and it will effectively protect a group of many motors when the open circuit is between the source and the bus As shown in Figure 4 the NBVllA is a high speed relay and a timing relay should be used to prevent false tripping or alarm When undervoltage tripping is permissible the scheme using a 27 device ...

Page 4: ...ll define the relay pickup voltage VR as the single phase voltage that when connected to the relay as shown in Figure 10 will just cause the relay to pick up This will be between 10 and 20 volts for the 120 volt relay and between 17 and 34 volts for the 208 volt relay The corresponding negative phase sequence voltages are 5 8 11 5 for the 120 volt relay and 10 20 for the 208 volt relay The operati...

Page 5: ...potential transformers are connected in open delta as shown in Figure 6 B the burden is as shown in Table III For the best division of burden it is recormnended that terminal No 6 of the relay be connected to the MID point of the delta connected potential transformers TABLE III CURRENT MA VA BURDEN PER P T VOLTS FREQUENCY 15 I6 I7 P T 4fl P T 4f2 120 60 115 38 9 23 4 56 120 50 40 95 66 4 80 7 82 2...

Page 6: ...tages seen by the relay are the same as the relay would see if it were connected to a three phase system that had one phase shorted Thus if we assume v12 is shorted then in equation 1 V1 2 0 v2 3 v2 3 Then equation 1 will reduce to v2 3 3 At Pickup VR J3 VN since VR V2 3 in this case 2 After the amount of unbalance that can be tolerated in the line voltage VN has been determined then the pickup vo...

Page 7: ...he front of the relay case contains an interlock arm that prevents the cover from being put back in place until the connection plugs have been inserted The relay case is suitable for either semi flush or surface mounting on all panels up to 2 inches thick and appropriate hardware is available However panel thickness must be indicated on the relay order to ensure that proper hardware will be includ...

Page 8: ...s With the telephone type relay de energized each normally open contact should have a gap of 010 015 inch Observe the wipe on each normally closed contact by deflecting the stationary contact member towards the frame Wipe should be approximately 005 inch The wipe on each normally open contact should be approximately 005 inch This can be checked by inserting a 005 inch shim between the residual scr...

Page 9: ...wave should decrease Continue increasing resistor R1 until the minimum voltage occurs As the magnitude of the wave decreases it will be due to the fundamental wave decreasing The harmonic content of the wave will remain the same When the point is reached where the fundamental goes to its minimum value if there is much harmonic content in the wave the harmonic wave will predominate If practically n...

Page 10: ...by changing the Resistor R2 setting PERIODIC CHECKS AND ROUTINE MAIRTENANCE In view of the vital role of protective relays in the operation of a power system it is important that a periodic test program be followed It is recognized that the interval between periodic checks will vary depending upon environment type of relay and the user s experience with periodic testing Until the user has accumula...

Page 11: ...required RENEWAL PARTS Sufficient quantities of renewal parts should be kept n stock for the prompt replacement of any that are worn broken or damaged When ordering renewal parts address the nearest Sales Electric Company Specify the name of the part wanted complete nameplate data including the serial number of the the GE requisition number on which the relay was furnished 11 Office of the General...

Page 12: ...9A0254 Potential Transformer Connections for Type NBV11A Relay 0418A0807 2 Test Connections for Checking R C Circuit Adjustment 0418A0805 Internal Connections for Type NBV11A Relay Front View 0459A0252 1 System Voltages under Balanced and Unbalanced Conditions 0459A0223 2 Test Conditions for Setting Pickup of Type NBV11A Relay 8025039 Cross Section of Drawout Case Showing Position of Auxiliary Bru...

Page 13: ...H tt tt r 4 Jt r _ h tt R H H d i t 1 GEI 50261 1 1 ttt t ft i i 1 i t 0 0 0 0 0 t N i Figure 4 SONOJ3Silll Nl 3 11 0459A0251 Operating Times of Type NBVllA Relay Contacts When Unbalanced Voltage Is Suddenly Applied 13 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 14: ... t 1 H 1 0 r M h _4j 1 t tl t i t _ 0 1 0 M _ i t t t r c c I I f c t t tf t _ t t j I fhl l0fi W 1 0 N M SONOJ3Sill1Vi t _ _ t 7 t o t l 1 0 0 M Nl Vi 11 _J_ 1 1 1 t T rq I tt i 0 Figure 5 0459A0250 Operating Times of Type NBVllA Relay Contacts When Unbalanced Voltage Is Suddenly Removed 14 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 15: ...NNECTION FOR WYE CONNECTED P T S l 5 i L 1 0 6 B P T SECONDARIES 7 RELAY S1UDS RECOMMENDED CONNECTION FOR OPEN DELTA P T S Figure 6 0459A0254 Potential Transformer Connections for Type NBVllA Relay 15 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 16: ...GEI 50261 1 t l RATED VOLTAGE 3 FREQUENCY 2 2 3 1 3 9 10 Figure 7 0418A0807 2 Test Connections for Checking R C Circuit Adjustment 16 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 17: ...4 GEI 50261 TR I l i 5 7 6 I I I 111 112 fl j AUTo TRANSFORMER r 9 8 TR 10 x SHORT F I NGER Figure 8 0418A0805 Internal Connections for Type NBVllA Relay Front View 17 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 18: ...TIONS VT 2 b UNBALANCED BY SHIFT OF ONE CORNER c UNBALANCED BY SHIFTING TWO CORNERS b TOWARD EACH OTHER ALONG VECTOR BETWEEN THEM 2 Figure 9 0459A0252 1 System Voltages under Balanced and Unbalanced Conditions 18 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 19: ...AC VARIAC GEI 50261 1 2 4 6 9 COAITI VVITY LIGHT 10 W 7H VOLTA SOVI CI Figure 10 0459A0223 2 Test Connections for Setting Pickup of Type NBV11A Relay 19 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 20: ...E AF TER ENGAGING AUXILIARY B RUSH CONNECTING PLUG TRAVELS Y4 INCH BEFORE ENGAGING THE MAIN BRUSH ON THE TERMINAL B LOCK Figure 11 8025039 Cross Section of Drawout Case Showing Position of Auxiliary Brush 20 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 21: ...760X0 0003 T SI TARGET 1 SEAL IN T D C TIME DELAY CLOS lNG F RA IC FILTER OtS5AS788 I I I I I I I 1 I I PT S I I J I I I j _J_ I J _ II _____ _ WHEII USED r l J o F _ J I 7 5 FUSES IF U f D AUX PT I I RATIO T D C t USE 27 TO TRIP S2 OR 1LARM IF UNDER VOLTAGE TRIPPING I Is PER MISSIBLE USE __ 62 _ TO Tm _52_ OR IlARM IF UNDER VOLTAGE I TRIPPING i IS NOT PERMISSIBLE Figure 12 0459A0253 Sh l 4 Typica...

Page 22: ...0 8 6 4 2 L 29MM I 6 187 1 9MM 3 0 I 157MM 76MM 4 I II I I 4 406 l 112MM I _i_ CUTUUT 8 81 I 224M III 2 843 f 2 M 72MM 1 218 f t ____ 5MM 5 687 PANEL I I II 144MM 5 25 BACK VIEW DRILLED HOLES 1 156 29MM FOR PANEL DRILLING SEMI FLUSH MOUNTING 133MM 3 4 DRILL 10 HOLES 19MM PANEL DRILLING FRONT VIEW FOR SURFACE MOUNTING FRONT VIE 1 TYPICAL DIM INCHES MM Figure 13 6209271 8 Outline and Panel Drilling ...

Page 23: ...I il e I oc3ood 0 0 OG2 GEI 50261 BACK VIEW OF CASE Figure 14 0178A5824 1 Outline and Mounting Dimensions for the Harmonic Filter 23 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

Page 24: ...3 94 200 Protection and Control GE Technology Center 205 Great Valley Parkway Malvern Pennsylvania 19355 1337 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...

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