Summary of Contents for Circuit Shield 87B

Page 1: ...edance Differential Relay CIRCUIT 0SHIELD Type 87B Catalog Series 419B H I G H I M P E D A N C E O I F P E R E N T I A I R E L A Y 0 2SQ a too t s 400 TR VOLTS AC RMS SET TES1 ABB Power TSD Company A f n o w n P U S A v Courtesy of NationalSwitchgear com ...

Page 2: ...eries 219B are covered in IB 7 6 1 7 5 PRECAUTIONS The following precautions should be taken when applying these relays 1 Incorrect wiring may result in damage Be sure wiring agrees with the connection diagram for the particular relay before the relay is energized Be sure control power is applied in the correct polarity before applying 2 Apply only the rated control voltage marked on the relay fro...

Page 3: ...he relay case The terminal is marked G In all applications this terminal should be wired to ground A lockout relay must be wired as shown in Figure 3 DC must be connected in the proper polarity as shown in the diagram To obtain best sensitivities and facilitate lower pickup settings the junction points of CT leads should he made equidistant from all CT s or leads of equal resistance provided 3 SET...

Page 4: ...transformers Check polarity at CT s and connections to the relays Exercise test push button to check proper operation of 87B and lockout relays 8 2SO 209 33 1 197 6 562 166 69 6 873 174 63 30 16 t 500 12 7 RAMIL C 2 4 673 123 63 3 1 J T 2 437 61 91 I a O SIOC VIEW FRONT VICW 4 ins0 HOLts f T n n n rrn n 0 0 0 0 0 0 0 1 jL tr 93 66 0 PANEL CUTOUT I T 0 0 0 0 0 0 0 0 iui hSS 32 36 L 0 4 H U H 3 2 I ...

Page 5: ...a 3 TO u it DC IDENTICAL RELAYING CONTROL POWER i _l i i i i 1 i OF 5 g c BUS B 00 cr 3i 3 CRO i i L irn O TIE 52 52 52 52 Cu o CD O 3 a o s c r 878 3 S7B 2 pj 1 1 i 9 A A A i 1 f i f 0 p 86 B6 88 C cn 8 L 6 L I 87B High Impedance Bus Differential Relay Figure 3s Typical External Connections Catalog Series 419B for Protection of Multiple Bus Sections with Bus Ties td ON p 00 CD L ...

Page 6: ... Pickup 5 of setting at 25 C Tolerance Operating Time Total trip time 23 40 milliseconds includes 20 30 msec time of the lockout relay and 3 10 msec operating time of 87B relay Input Withstand 150 Volts RMS continuous 400 Volts RMS for 5 minutes 1500 Wattsec max at voltage limiting conditions internal system faults 25 50 60 Hz Frequency Voltage Limiting 1200 1500 Volts instantaneous at input curre...

Page 7: ...FI and flux exchange between current transformers The relay is equipped with voltage limiting power resistors metal oxide varistors to limit the input voltage to safe values during internal system faults Input burden at heavy faults is in essence a relatively high dc voltage in series with a resistance of a few ohms which practically does not impede the build up of CT summation currents Hence the ...

Page 8: ...either lightning arresters directly connected to the bus or non relayed capacitors with grounded mid points or other equipment subject to high magnetizing inrush or non canceled infeed should be referred to the factory Application of the Type 87B relay and calculation of proper settings require consideration of the above described properties of the scheme In general and to provide optimum performa...

Page 9: ...Current Symm RMS Max system fault current Symm RMS Max relay Current Symm RMS Current Transformers Max system fault current Symm RMS relay Current Symm RMS Minimum Ratio Max Max Satur Voltage Minimum Ratio Minimum Ratio Max Satur Voltage Satur Voltage 170A 240V 1500 5 1200 5 800 5 50 KA 37 5 KA 25 KA 100A 2500 5 2000 5 1500 5 50 KA 37 5 KA 25 KA 350V 300A 170V 1000 5 800 5 500 5 50 KA 37 5 KA 25 K...

Page 10: ...also check the approximate number of circuits or breakers that can be connected to the relay at a desired current sensitivity and voltage setting To obtain the number subtract the relay current from the required fault current sensitivity and divide by the magnetizing current of one CT Current Transformers Wiring The relay is designed for use with dedicated CT s Toroidal or bushing type current tra...

Page 11: ...access to all external circuits wired to the case See Instruction Book IB 7 7 1 7 8 for details on the use of this device Also see note on page 13 2 HIGH POTENTIAL TESTS High voltage insulation tests are not recommended for the relay circuits The relay has been tested at the factory If a control wiring insulation test is required remove the drawout assembly from the case before applying test volta...

Page 12: ...d the test circuit should contain properly selected current transformers of allowable ratio and saturation voltage and a lockout relay interconnected as in the contemplated differential scheme 1 Connect relay drawout assembly as shown in Figure 4 Apply proper DC control voltage per relay rating 2 Increase test voltage gradually until the 87B relay operates NOTE The output relay will continuously o...

Page 13: ...P TRANSFORMER e O o o Figure 4 Test circuit bench tests of drawout unit Note on the use of the MT XC Test Plug Catalog No 400X0001 When using the test plug in the Type 87B relay case access to the external CT circuit is obtained at any of the three current circuit shorting switches In other words the CT shorting switches are in series in the CT secondary circuit Courtesy of NationalSwitchgear com ...

Page 14: ...was of non drawout construction Both series are In the event that a 219B series unit is to be replaced with a 419B series unit the following applies The entire case assembly must be replaced Be sure to de energize all equipment and short current transformer secondaries before disconnecting any wires The 419B case assembly will mount in the same panel cutout as the 219B series unit 1 The connection...

Page 15: ...lt protection for transformer or generator windings This arrangement is sometimes referred to as restricted earth fault Protection The scheme provides sensitive ground fault detection for its zone of protection and is stable for faults outside the zone All four ct s must have the same ratio and be dedicated to the 87B relay iZ iri 0 7 06 j OG O H TYPE 67B r 86 286 Courtesy of NationalSwitchgear co...

Reviews: