Air & Moulded Case Circuit Breaker Service & Maintenance

Charnchanok T., Low Voltage Products Division Air & Moulded Case Circuit Breaker Service & Maintenance November 12, 2013 Slide 1

Air Circuit Breaker : New Emax Series Reliability and sturdiness - Materials - Assembly - Testing stage Standardized range of accessories Certifications IEC / UL November 12, 2013 Slide 2

Protection & Reliability Guarantee Make Sure!!! Preventive Maintenance Condition Internal components Correct Installation In, Icu Parameter settings Accessories Network Configuration Etc.. November 12, 2013 Slide 3

Main parts of the circuit breaker Main Circuit: Terminals, fixed contacts, moving contacts. Arc Chambers: Operating Mechanism: ON Overcurrent release: Actuating ti Release: TRIP Thermomagnetic & Electronic OFF Shunt Opening / Shunt Closing Auxiliary Contact: NO / NC Contact Position November 12, 2013 Slide 4

Maintenance Lifetime? Mechanical & Electrical Life? November 12, 2013 Slide 5

Circuit Breaker : Communication Accessories BT030 Bluetooth th Portable Maintenance Device Real-time Monitoring (A) Parameters Reading 20 Last Trip history Fault Current Values 20 Last Events Alarm Messages Password Required for some operations Bluetooth Configuration PR121/P, PR122/P, PR123/P,Tmax PR222/P November 12, 2013 Slide 6

Circuit Breaker : Communication Accessories SD Testbus Software November 12, 2013 Slide 7

Circuit Breaker : Communication Accessories November 12, 2013 Slide 8

Circuit Breaker : Test & Maintianace Equipment Protection Unit Release Command Re-check and Setting Parameters Motor Load for each particular load Capacitor Transformer Check Type of Last Trip L, S, I,G and Fault Current Values November 12, 2013 Slide 9

Circuit Breaker : Test & Maintenance Equipment Protection Unit Release Command Yearly Preventive Maintenance with Testing Protection ti Unit by PR010/T November 12, 2013 Slide 10

Circuit Breaker : Test & Maintenance Equipment Protection Unit Release Command Yearly Preventive Maintenance with Testing Protection ti Unit by Ekip November 12, 2013 Slide 11

November 12, 2013 Slide 12 Circuit Breaker : Test & Maintenance Equipment

November 12, 2013 Slide 13 Circuit Breaker : Test & Maintenance Equipment

November 12, 2013 Slide 14 Circuit Breaker : Test & Maintenance Equipment

November 12, 2013 Slide 15 Circuit Breaker : Test & Maintenance Equipment

Circuit Breaker : Test & Maintenance Equipment Protection Unit Release Testing by TS3 Inject real secondary current/voltage to verify correction and reliability of protection unit release. (Both of microprocessor and measuring A/D converter) ( L,S,I,G, Current, Tripping time and Tripping Mechanism) November 12, 2013 Slide 16

Maintenance : Period recommended November 12, 2013 Slide 17

November 12, 2013 Slide 18

November 12, 2013 Slide 19

Automation Technologies Sector - Maintenance Circuit breaker type Serial number, Accessories Duty (normal, heavy) Ambiente (normal, dusty, polluted) General inspection Check of jaw type contacts (cleaning and greasing) Check of the arcing chamber (tracking,colour) colour) Check and cleaning / replacement of the fixed contacts Check and cleaning / replacement of the moving contacts Check of the sequence of the contacts November 12, 2013 Slide 20

Automation Technologies Sector - Maintenance Check of the operating mechanism (cleaning, greasing, replacement of the closing springs) Check and test of the accesories (shunt opening release, closing coil, motor operator, undervoltage release ) Check and test of the electronic release with TS3, PR010T,Ekip Mechanical test of the electromagnetic release Service temperature t check Thecnical report with operations and suggestion. November 12, 2013 Slide 21

Temperature derating November 12, 2013 Slide 22

Temperature derating November 12, 2013 Slide 23

Parameters Setting Transformer Delta-Star 1000KVA, Ucc 5%, Un400V Transformer In = (1000 x 1000) / (1.732 x 400) = 1,443 A Icc = (1443 x 100) / 5 = 28.9 KA Select New Emax E2B16 PR121/P-LSIG In 1600 Icu 42KA @ 400Vac Note Icu (CB) 42KA > Icc 28.9KA Iu (CB) > Ib (TM ) November 12, 2013 Slide 24

Parameters Setting L Overload Protection I1 = Ib(TM)< Iz of Busduct L = I1 / In(CB) = Ib (TM ) / In(CB) = 1443 / 1600 = 0.9 t1 = 36 Sec November 12, 2013 Slide 25

Parameters Setting Time-Current discrimination Trip selectivity among protections is obtained by delaying the tripping time of supply side protections with respect to load side protections November 12, 2013 Slide 26

Parameters Setting I3 < Max Iscs at Busbar I < Iscc (at Busbar) / In(CB) < 31,000 x 0.5 / 1600 < 9.5 Note Short circuit Protection Function < Max Iscc November 12, 2013 Slide 27

Parameters Setting I3 < Max Iscs at Busbar Isc of Gen < 3( 3-5) ) x Irated (Generator) I < 3.5 Note Short circuit value of Generator is not so high November 12, 2013 Slide 28

Parameters Setting I2 < Iscs at end of cable S < Iscc (end of cable) / In(CB) < 22,000 x 0.5 / 1600 < 7 Note Short circuit Protection Function < Max Iscc November 12, 2013 Slide 29

November 12, 2013 Slide 30

Parameters Setting Short-circuit protection when: Time selectivity is required There are capacitor-banks on the load side There are LV/LV transformers on the load side There are motor on the load side There are high current peaks due to load with high inrush 6 < S < 7 t2 = 0.5 Sec (I2t) Note Shortcircuit time gap should greater than 100ms November 12, 2013 Slide 31

Parameters Setting I4 : Consider Normal Operation Ground Fault Protection : Ideality Ground Bar has voltage @ 0 volt Ground Bar has Current @ 0 Amp Some load characteristis create ground current on normal operation G = 0.3 t4 = 0.2sec I 2 t Note Ground Fault Protection < Isc L-PE (KA) I4 < I1 (G< L) November 12, 2013 Slide 32

Nuisance Trip of Circuit Breaker Main Causes 1. Shunt Opening Release Command 2. Undervoltage Release Command Mechanical Indicator NOT active Mechanical Indicator NOT active 3. Protection Unit Release Command Mechanical Indicator Active November 12, 2013 Slide 33

Nuisance Trip of Circuit Breaker Shunt Opening Release Command Check Source Command to Shunt Opening Release at Terminal C11 / C12 November 12, 2013 Slide 34

Nuisance Trip of Circuit Breaker Under Voltage Release Command Check proper command to Under Voltage Release at Terminal D1 / D2 Consider Sag Voltage Problem ( See following pages ) November 12, 2013 Slide 35

Nuisance Trip Sag Voltage L1 L2 L3 N Good protection - 3 -Phases monitored - Adjustable Over&Undervoltage -Adjustable delay-time - Prolong undervoltage release s coil - When Sag Voltage occur, UVR will trip immediately ( delay-time by 3-phase monitor can Not hold) L1/L2/L3 UVR 3-Phases Monitoring November 12, 2013 Slide 36

Nuisance Trip Sag Voltage Undervoltage Release For Air-Circuit Breaker The circuit breaker is opened with release power supply voltage of 35-70% Un The circuit breaker is closed with release power supply voltage of 85-110% Un November 12, 2013 Slide 37

Nuisance Trip Sag Voltage Time-dely device ( YU Delay ) To sustain undervoltage release s coil on closing position, even no power supply Adjustable dalay time for maxmimum 3 sec. November 12, 2013 Slide 38

Electrical Accessories L Time-delay device for undervoltage release N When Power Supply is AC Short terminal 3 and 4 D1 D2 Delay time setting terminal 6-10 November 12, 2013 Slide 39

Nuisance Trip Sag Voltage L1 L2 L3 N Perfect protection - Total Delay-time is summary of YU Delay plus phase monitor - Suggested maximum delay time is 3 sec. - Each undervoltage release has its particular type of time-delay device - The solution can prevent network from sag voltage problem L1/L2/L3 3-phase monitor UVR Deley-Time November 12, 2013 Slide 40