Summary of Contents for HU

Page 1: ...is match e g 10 transformer tap changing plus 5 ct mismatch The 35 sensitivity relay handles as much as 20 mismatch See Figures 13 and 14 for a comparison of the characteristics of the two sensitivities Any of the relays may be recalibratedin the field to obtain either characteristic HU 4 1 APPLICATION The types HU HU 1 and HU 4 relays are high speed relays used in the differential protection of t...

Page 2: ...Transf 4 Restraint Transf t Restraint Transf 2 Restraint Transf 3 1 f VT r t i k j 1 L p igrlt rf 1 1 1 1 1 LL I si pR lvi k i i jj l i Restraint Transformers DU Indicating Contactor Switch ICS Restraint Transformer DU i w t Indicating Instantaneous Trip IIT Indicating Contactor Switch ICS M Indicating Instantaneous Trip IIT To Restraint Transf 3 HU 1 Only To Restraint Transf 2 To Restraint Transf...

Page 3: ...rating Transf HRU i Operating Transf HRU t Operating Transf DU vj j Operating Transf DU ISIS 7 E 3 L M J r M i L J 1 5 3 V s v i V Operating Circuit Filter Capacitor HRU 4 MFD S Operating Circuit Filter Capacitor HRU 4 MFD T l R 1 Capacitor 0 45 MFD HRU Restraint F liter Circuit rCapacitor 0 45 MFD HRU Restraint F it ter Circuit a 4 4 Figure 4 Type HU 4 Relays Rear View Figure 3 Type HU HUH Relays...

Page 4: ...so during this operation two fingers on the arma ture deflect a spring located on the front of the switch which allowsthe operationindicator target to drop The front spring in addition to holding the target provides restraint for the armature and thus controls the pick up value of the switch 2 5 Indicating Instantaneous Trip Unit NT The instantaneous trip unit is a small ac operated clapper type d...

Page 5: ...Fault Currents The HU family of relays have a variable percentage characteristic This means that the operating current required to close the contact of the differential unit expressed in percent of restraint varies with the magnitude of the larger restraint current in the HU and HU 1 current relays and with the sum of the re straint current in the HU 4 relays Figures 13 and 14 illustrate these cha...

Page 6: ...the lead located in front of the tap block to the desired setting by means of a screw connection 3 4 Breaker Maintenance Before some of the ct s are bypassed for breaker maintenance the trip circuit should be opened as shown in Figures 9 through 12 Otherwise the false unbalanced current will cause the relay to trip It is not necessary to short circuit the relay operating cir cuit since it has an a...

Page 7: ...nstanta neoustripunit This unit is set at the factory to pickup as follows HU HU 1 Relays 10 times tap value current HU 4 Relay 15 times tap value current 6 SETTING CALCULATIONS Select the ratio matching taps There are no other settings In order to calculate the required tap set tings andcheck current transformer performancethe following information is required 6 3 Calculation Procedure a Select c...

Page 8: ...S 0 15 ZA ohms ZT 3 1 13RL where S is the smaller of the two terms T 0 45 W or 4 3 4 RL T 3Za h Examples Refer to Tables 6 and 7 and Figure 20 for setting ex amples For 3 winding banks Repeat calculation of equation 1 and apply sim ilar equations to calculate mismatch from the intermediate to high and from and from the inter mediate to low voltage windings Where tap changing under the load is perf...

Page 9: ...ctory and should not be disturbed after receipt by the customer 8 1 3 Indicating Contactor Switch ICS Block contacts of the polar units closed Pass suffi cient direct current throughthetrip circuit toclosethe contacts of the ICS This value of current should be not greater thanthe particular tap settingbeing used The operation indicator target should drop freely 8 1 Performance Check The following ...

Page 10: ...ies the lower tap block In the HU 1 Terminal 5 supplies the first upper tap block Terminal 7 supplies the second tap block and Terminal 9 supplies the lower tap block In the HU 4 Terminal 13 supplies the first upper tap block Ter minal 5 supplies the second tap block Terminal 7 supplies the third tap block and Terminal 9 supplies the lower tap block ISR should be connected to the Terminal with the...

Page 11: ...5 and lac which is between 8 3 and 9 2 amps NOTE Inadjustingeither thestationarycontact or backstop the screw in the elongated holes of the assemblies should be loos ened not removed during the adjust ment procedure a Upper Unit HRU Place a 0 065 to 0 070 inch feeler gauge between the right hand front view pole face and the arma ture This gap should be measured near the front of the right hand pol...

Page 12: ... 7 6 9 8 1 4 9 lAc Min lAc Max 2 7 4 0 3 2 17 3 10 6 9 0 7 6 5 4 3 1 4 4 7 0 10 5 10 5 10 5 10 5 10 5 ISR 8 3 14 5 6 9 3 8 5 7 lAC Min lAc Max 3 0 3 5 16 1 9 2 6 3 7 7 4 2 3 3 7 6 11 4 11 4 11 4 11 4 SR 14 1 7 9 6 5 5 2 3 2 lAc Min lAc Max 3 8 16 0 8 7 7 2 3 6 5 7 8 4 12 6 12 6 12 6 ISR 12 9 6 2 3 5 4 7 lAC Min lAc Max 4 2 14 2 6 9 5 2 3 9 13 8 9 2 13 8 SR 12 4 5 3 3 9 lAC Min lAc Max 4 6 13 7 5 9...

Page 13: ... 2 4 3 5 9 6 8 9 0 10 5 12 2 18 4 4 8 6 5 7 6 10 0 13 5 11 6 20 3 ISR 10 5 10 5 10 5 10 5 10 5 7 0 lAc Min lAC Max 3 5 4 7 5 7 7 9 9 3 10 9 17 3 5 2 6 3 8 7 10 2 12 0 19 2 SR 11 4 11 4 11 4 11 4 7 6 lAC Min lAC Max 3 8 5 1 7 4 8 8 10 5 17 1 5 6 8 2 9 7 11 6 18 9 ISR 12 6 12 6 12 6 8 4 lAC Min lAc Max 4 2 5 5 6 9 8 6 15 5 6 1 9 5 7 7 17 1 ISR 13 8 13 8 9 2 lAC Min lAC Max 4 6 6 1 7 8 15 2 6 8 8 6 1...

Page 14: ...2 4 4 5 9 6 9 12 2 9 1 10 5 18 5 4 8 6 5 7 6 13 5 10 1 11 6 20 5 ISR 10 5 10 5 10 5 10 5 10 5 7 0 lAC Min lAc Max 3 5 4 8 10 9 5 7 7 9 9 3 17 4 5 4 6 3 8 8 10 3 12 1 19 3 ISR 11 4 11 4 11 4 11 4 7 6 lAc Min lAC Max 3 8 5 2 10 5 8 9 17 3 7 4 11 6 19 2 5 7 8 2 9 8 ISR 12 6 8 4 12 6 12 6 lAC Min lAc Max 4 2 8 7 15 8 5 6 7 0 9 6 17 2 6 2 7 8 ISR 13 8 9 2 13 8 lAc Min lAc Max 4 6 7 9 6 2 15 2 16 8 6 8 ...

Page 15: ... very short period of time and it should be suddenly interrupted Adjust right hand shunt on upper polar unit until it trips with lac 33 of tap value amperes Lower lac gradually to 15 of tap value current and adjust left hand shunt until unit resets Repeat these steps if neces sary until the unit operates at 33 or slightly lower of tap value current immediately following the appli cation of 20 time...

Page 16: ... lower polar unit should operate between the following values Relay Type lac ILR Relay Type lac LR HU HU 1 4 times tap value current 10 to 9 tap value current HU HU 1 1 64 times tap value current 45 times tap HU 4 1 5 times tap value current 56 times tap HU 4 4 times tap value current 11 2 to 10 6 tap value current This changes the percentage slope curve of the re lay to that shown by the 35 perce...

Page 17: ...ned by using a high resistance ac voltmeter should be within the range given in Table 5 Refer to Figure 24 or Figure 25 for bridge location depending on relay type 10 2 9 Diode Check Check for open or shorted diodes using the electrical checkpoints of Table 5 11 RENEWAL PARTS Repair work can be done most satisfactorily at the factory However interchangeable parts can be fur nished to customers who...

Page 18: ...ng Circuit Operate Coil Bridge Operate Transformer HRU 1 Output of operate transformer top coil terminals 2 4 MFD capacitor HRU Operate 3 45 MFD capacitor HRU Restraint Rectifier Bridges 4 Operating 5 Restraint 6 Series Filter Reactor 2 50 3 10 2 17 2 69 3 60 7 00 2 40 4 75 3 90 4 80 3 98 4 89 2 27 3 13 2 41 3 33 3 20 4 40 2 89 3 97 1 95 3 00 1 87 2 88 1 0 1 2 1 0 0 5 18 Courtesy of NationalSwitch...

Page 19: ...atio from Table 1 IR relay continuous rating 5 Check IIT Operation Max Symmetrical error current 10 times relay tap 6 Determine Mismatch Mismatch 1 890 TH 4 6 NO No No 8 05 8 7 4 18 4 6 100 T 8 7 u V 4 6 RH 100 TL 1 92 1 89 100 1 6 TH 1 89 7 Check ct Performance 0 45 0 15 Zj 3 4 RL 1 13 RL T T 0 45 0 15 3 4 0 4 1 36 0 05 1 13 04 0 45 0 03 8 7 4 6 1 41 ohms 0 48 ohms N 200 40 Np 0 833 0 333 NI 240 ...

Page 20: ... 33 9 32 Amp RH RL 4 82 9 32 Rl 3 Calculate Current Ratios 1 55 3 01 I 3 10 I 3 10 RH RH 4 Select Tap Ratio from Table 1 Ti 4 6 8 7 1 586 T 3 00 L 2 9 TH 2 9 IR relay continuous rating 5 Check IIT Operation Max symmetrical error current 10 times relay tap No No No No No No 6 Determine Mismatch T I T T I RH _ 1 H MRL V V Rl U V RH Mismatch 100 100 100 TH TL RI T I TH I RL 3 10 2 9 4 82 4 6 4 82 4 6...

Page 21: ...45 3 4 0 5 1 13 0 5 3 4 0 5 2 9 4 6 8 7 0 57 0 02 1 7 0 16 1 7 0 10 1 80 ohms 0 59 ohms 1 86 ohms 200 80 120 N 0 833 0 333 1 0 NP FTT NPVCL 240 240 120 200 1 0 800 0 333 200 0 833 2 0 1 67 2 67 100 100 100 100 NPVCL Yes Yes Yes ZT 100 T 4 6 TL 8 7 TH 2 9 Conclusion Requires 35 Sensitivity Relay Since LTC M 15 21 Courtesy of NationalSwitchgear com ...

Page 22: ...at 20 times tap value current at 8 times tap value current at tap value current Continuous Tap Rating HU HU HU 4 HU 4 HU HU HU 4 HU 4 2 9 10 35 32 487 483 2 26 2 18 76 89 3 2 12 34 31 499 2 30 2 23 78 92 509 3 5 13 33 30 2 30 504 512 2 19 81 95 3 8 14 33 30 2 30 2 27 83 98 547 543 4 2 15 31 546 29 2 30 2 19 100 554 84 4 6 16 30 29 2 40 2 33 88 104 598 598 5 0 18 29 28 640 610 2 50 2 37 92 106 8 7 ...

Page 23: ...IAL UNIT DU BOTTOM XXXXXJOOC OCXXXXXX THROUGH RESTRAINT TRANSFORMER THROUGH NSTRAINT TRANSFORMER jjj CHASSIS OPERATED SHORTING SWITCH REO HANDLE TEST SWITCN CURRENT TEST JACK TERMINAL CNASSIS OPERATED SHORTING SWITCH RED HANDLE TEST SWITCH CURRENT TEST JACK TERMINAL r i NCTE i L _Y _ NOTE TERMINALS 3 N 6 ARE TO BE JUMPEREO AT RELAY CASE TERMINALS 3 N 6 8 ARE TO BE JUMPEREO AT RELAY CASE i TAP TERM...

Page 24: ... UNIT DU BOTTOM SHUNT THROUGH RESTRAINT TRANSFORMER CHASSIS OPEKATEO SHORT NO SWITCH REO HANDLE TEST SWITCH CURRENT TEST JACK TERMINAL FRONT VIEW INTERNAL SCHEMATIC TERMINALS 3 t B 2 ARE TO BE JUHPEREO AT RELAY CASE ADDITIONAL FLUX PATH TAP TERMINAL 1 CONNECTION 3 w 5 i N UNBALANCED AIR GAPS Sub 5 183 A 062 Sub 6 188 A 542 Figure 8 Polar Unit Permanent Magnet Flux Paths Figure 7 Internal Schematic...

Page 25: ... rm _ _ rm _ ttJ r Y i v Y Y D C TRIP S I l l I mg B 9 nc re PH fl mg c tang RS M W c R B C OJ DEVICE Hid CMRT HLJ I JIT ICS l mnGCD B no c COnCCTEO SRC re mg n 43 TYPE M fUOLimv TRIPPING SCLAV B 7 TYTC MJ DirrDEKTIA ECLAT DJ oirmcMTin LMIT 0 CPCRftTING COIL R ECSTRAINT COIL TRIP QJTCrr MITCH OJ n OROflU OCK 2 ND HSRCNIC PASS TILTER rm ifi B V 2 0 IHROUC EL OCX FILTER R I 41 R 2 THRUM RESTRAINT IR...

Page 26: ...r rrru _ DU I concert HITH HH ON _ Y r i l i VI Y 3 Y 2 i p c TRIP ag frflSC 0 S g RS PH R BfgC C g g RB TV R I P 06 H B fl C 9 DU DCVICE KXBER OART 43 TRIP CUTCFT WITCH TYPE M KftJLIPRY TRICING KXRY 0 TYPE KJ DIFFERENT IK RELRY Du OirrpcvfTl WIT 0 CURATING COIL R RESTRAINT COIL vnj FlMMNTn 0 LOCX 2 NO V 4 W 3 NIC PRSS FILTER 06 IIT ICS l RISES B fVA C COMCCrED SRC ne nnsc R Hi rm n IE 2 ND IFWCNI...

Page 27: ... r rcr r rcr H TTU POS 87 r re PmSES B AND C COMCCTED SPfC RS PHRSE R PHRSE B PHRSE C IC Sffrg RS PH fi SATE RS PH fl DEVICE NUMBER CHflRT 1 HRU 43 TRIP CUTOFF SWITCH TYPE H _ AUXILIARY TRIPPING REU TYPE HJ HJ 1 DIFFERENTIAL RELfi DIFFERENTIA UNIT 0 OPERATING COIL R RESTRAINT COIL I FUNDRf ENTRL BLOCK 2 ND HPRMONIC PR 55 FILTER IT I IT ICS 86 T T DU 87 mnDU 9 2 ND HARMONIC 4 BLOCK FILTER 1 R HRU i...

Page 28: ... o OPERATING z R RESTRAINT CC Rl l PHASE A C IL CIRCUITS 4 J Sfc ST 2 l Si _ CO CIRCUITS f a c w OC _ TEIP _ US P 4 m t TnlftAH RESTRAINT TRANSPORTERS l K ICS HRU HARMONIC RESTRAINT UNT 0 OPERATING CC R RESTRAINT ecc K S INOICATIN 4 CONTACTOR SWITCH t I T INDICATING INSTANTANEOUS T IP PHASES e AND r CONNECTED SAME AS PHASE A PHASE B SAME AS H A PHASE C SAME AS PM P MRO 0 ruNDEMERTAl EUXC I 53 llT ...

Page 29: ... t il 7 t t r 4 14 i T T Vj i T 6 4 6 13 fc 77 3ff i i i 5 12 S i l 43 t n r 8 7 7 L 4 f 1 XT O 4 4 t f r t R5T4I 2 T 7 t t T rr UJ 3 2 z E 1 3314 s 4 t 2 Tf T T I 4 T T 7 T T T T t 2 r H rrr T T rT T T r i in T 7 r i 7 T T I i I i l s i i I I 4 I J 7 z t T Ld 8 h a a ac 0 TTT Z y t ry T T T t t Z r T 1 1 4 pH Z I U 5 CL O TT T T 4 t i t f 15 MISMATCH 2 T 7 i 3 7 t Sir 3TV 1 t 4r 2 Z T Vi TV T f 1...

Page 30: ...I y i i i 1 6 X m 1 3 ft j i 1 Si T X 5 1 1 2 5 5 1 3 M m i m i ft 8 7 7 b_ 4 m w rr rtft t O X 1 4 1 t 1111 X X T 2 4 1 1 4 4 f t u 3 f 1 i 3C T ft S t I h 2 j J 2 4 1 T J 4 HI I LLi U f x X 4X y Hi t y ft X i X a j ifti 1 jr 1 1 j 1 t 51 1 1 1 1 10 r f n t I I l I 1 X I X T 1 1 6 u i K x 1 a t 1 t 1 6 x U 11 5 I x 1 T y o 1 1 4 4 v H rftxri tx L J x i 20 MISMATCH i r r 3 J4 r r ZZ 77 nx 1 T T r ...

Page 31: ...R 3 5 h a EXTERNAL FAULT PROTECTED TRANSFORMER o o o o p nr o a INTERNAL FAULT i13 15 17 87 OP R R 3 5 h 5 b INTERNAL FAULT dtp Figure 15 Simplified Schematic of the Type HU Relay with Current Distribution for a External Fault b Internal Fault 31 Courtesy of NationalSwitchgear com ...

Page 32: ...O or u 3 0 CO h O o 2 0 Ui V X o cc a a i o 0 0 5 IJO 1 5 2 0 30 2 5 LARGER RESTRAINT CURRENT IN MULTIPLES OF TAP VALUE CURRENT Sub 1 619564 Figure 16 Differential Voltage Characteristic of the DU Unit of the HU 4 Relay with 0 30 Times Tap Pickup 32 Courtesy of NationalSwitchgear com ...

Page 33: ... LARGER RESTRAINT CURRENT IN MULTIPLES OF TAP VALUE CURRENT Sub1 619566 Figure 17 Differential VoltageCharacteristic of the DU Unit of the HU 4 Relay with 0 35 Times Tap Pickup 33 Courtesy of NationalSwitchgear com ...

Page 34: ...l Tripping Time Characteristic 400 o 300 fsl OC LU O 200 UJ a I00 o o Q _ 0 ao I20 200 0 40 I60 280 240 Sub 2 471052 FREQUENCY IN HERTZ Figure 19 Typical Frequency Response of the HU and HU 1 Relays 60 Hertz 34 Courtesy of NationalSwitchgear com ...

Page 35: ...VA M 40 000 KVA S 30 000 69 000 KVA M 10 000 KVA s 7 500 12 400 KVA M 20 000 KVA S 16 000 VL 12 400 VOLTS Ny 240 TURNS Vcl 200 VOLTS RL 0 4 OHMS DELTA CT lext IOOA KVA M 20 000 KVA S 16 000 69 000 KVA M 40 000 KVA S 30 000 161 000 V V VH V I L H 120 2 40 NT 240 120 NT Ny Ny 200 200 800 V V 200 VCL V CL CL CL 0 5 0 5 0 5 RL rL RL 0 4 R L DELTA CT DELTA CT WYE CT WYE CT r k Sub 2 289 B 412 8 0 Figur...

Page 36: ...l i i L I I 10 1 I 7 9 4 6 e 2 JO T I L OPTIONAL LEAD CONNECTION FOR TYPE HU l RELAY TRB I 407 C 275 G 0 3 TRR 1 N 07 C 27 S 003 2 KX 6 Ai 10 Ri rL S P O T SWITCH 2 f P 3 S P D T SWITCH rORi fQR 2 R 3 120 V A C 120 V A C POS 0 c POS VOITACE oc NEC NEG VOLTAGE Sub 5 290 B 506 Sub 1 1483 B 36 Figure 22 Test Circuit of the HU 4 Relay Figure 21 Test Circuit of the HU and HU 1 Relays Courtesy of Nation...

Page 37: ...I L41 347 1S Figure23 Variation of Second Harmonic Content of Test Current 37 Courtesy of NationalSwitchgear com ...

Page 38: ...a Q O o I I 50 5 CR3 CR6 i 0 8 f 6 I o cT 14 17 I LQL Q L _ 0 i 0i4 17 o o 8 cm I 18 O an r O o HID O t i i I R2 I FOR HU I ONLY G03 FOR HU 1 ONLY GOD SCHEMATIC 13 il DU HRU RESTRAINT 2 CR 4 RESTRAINT CRI 4 12 HRU DU OPERATE CR 2 RESTRAINT CR 4 2 3 10 FOR HU I ONLY 5 OU OPERATE CR3 DU Zl RESTRAINT 3 CR6 R I 17 16 14 Sub 2 718B654 Figure 24 HU HU 1 Diode Board Module Component Location 38 Courtesy ...

Page 39: ... 54 QZ 408Cki 4 0 J SCHEMATIC HRU RESTRAINT C R I DU RESTRAINT 7 C R 5 HRU OPERATE C R2 DU DU OPERATE C R 3 RESTRAINT 5 C R 6 H4 20 DU F DU RESTRAINT 8 RESTRAINT I 3 9 C R 4 C R 7 J z Sub 2 1479B20 Figure25 HU 4 Component Location 39 Courtesy of NationalSwitchgear com ...

Page 40: ...FOR THIN PANELS 5 16 18 SCREW FOR THICK PANELS IT USE 5 16 18 STUDS INTERNAL EXTERNAL TOOTH WASHERS T 1 813 46 05 16 it 4 it 1 1 2 0 I 50 8 NOTE PROJECTION HARDWRRE MUST BE ORDERED SEPARATELY I I 19 17 I 13 Itft 1 0 8 594 2 688 69 28 563 DIR 14 29 25 4 15 09 190 32 SCREW 2 HOLES FOR THICK PANELS USE 190 32 STUDS 5 750 146 05 5 375 136 53 2504 0161 397 0 h 6 350 C c 1 031 26 19 5 750 146 05 375 R 9...

Page 41: ...PANEL SPACERS FOR THIN PANELS 5 16 18 SCREW FOR THICK PANELS USE 5 16 18 STUDS INTERNAL EXTERNAL TOOTH WASHERS 2 608 68 28 563 DIR 14 29 2 HOLES T NOTE 5 750 146 05 PROJECTION HARDWARE MUST BE ORDERED SEPARATELY 5 375 136 53 4 016 397 B 190 32 SCREW 250 6 350 1 031 26 19 _TYP FOR THICK PFtttLS USE 190 32 STUDS 5 750 146 05 ft 375 R 9 53 1 594 1 0 15 09 T 25 4 21 T 3 7 9 1 9 641 DIR 16 26 PANEL 1 8...

Page 42: ...I L 41 347 1S 619583 Figure28 Typical Frequency Response of the HU and HU 1 Relays 50 Hertz 42 Courtesy of NationalSwitchgear com ...

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