Transcript FUSEOLOGY
Sistemas Eléctricos Industriales Coordinación Selectiva de los elementos de protección Referencia: http://www.bussmann.com •Definiciones •Coordinación con fusibles •Coordinación con interruptores •Ejemplo de coordinación en una planta industrial Presentado por: Jesús A. Baez M. ITESM, Departamento de Ingeniería Eléctrica Monterrey, NL Octubre 2007 © 2001 Cooper Bussmann, Inc. Selective Coordination Definition: The act of isolating a faulted circuit from the remainder of the electrical system, thereby eliminating unnecessary power outages. The faulted circuit is isolated by the selective operation of only the overcurrent protective device closest to the overcurrent condition. © 2001 Cooper Bussmann, Inc. Selective Coordination: Avoids Blackouts Without Selective Coordination With Selective Coordination OPENS NOT AFFECTED OPENS UNNECESSARY POWER LOSS NOT AFFECTED Fault Fault Selective Coordination: NEC® 240.2 Definitions Coordination. The proper localization of a fault condition to restrict outages to the equipment affected, accomplished by the choice of selective fault-protective devices. © 2001 Cooper Bussmann, Inc. Selective Coordination: Normal Supply Normal Source Emergency Source N E ATS © 2001 Cooper Bussmann, Inc. Selective Coordination: Normal Supply Normal Source Emergency Source Unnecessary Feeder Outage N Fault X1 E ATS Opens Not Affected Unnecessary Power Loss © 2001 Cooper Bussmann, Inc. Selective Coordination: Normal Supply Without Normal Source Emergency Source Unnecessary Main Outage N Fault X1 E ATS Opens Not Affected Unnecessary Power Loss © 2001 Cooper Bussmann, Inc. Selective Coordination: Normal Supply Without With Normal Source Emergency Source N Fault X1 E Normal Source Emergency Source N ATS E ATS Opens Not Affected Unnecessary Power Loss © 2001 Cooper Bussmann, Inc. Selective Coordination: Normal Supply Without With Normal Source Emergency Source N Fault X1 E Normal Source Emergency Source N ATS Opens Not Affected Unnecessary Power Loss E ATS Isolated to Branch Only Fault X1 © 2001 Cooper Bussmann, Inc. Selective Coordination Circuit Breaker Coordination © 2001 Cooper Bussmann, Inc. Coordination - Thermal-Mag Circuit Breakers Thermal Magnetic Molded Case Circuit Breaker TimeCurrent Curve Overload Region Instantaneous Region Interrupting Time Unlatching Time Interrupting Rating © 2001 Cooper Bussmann, Inc. Coordination - Thermal-Mag Circuit Breakers (See SPD) 400A 90A No se tiene selectividad para corrientes de corto circuito en este rango © 2001 Cooper Bussmann, Inc. Selective Coordination D Time C B A 4000A Fault Current © 2001 Cooper Bussmann, Inc. Lacking Coordination OPENS NOT AFFECTED UNNECESSARY POWER LOSS Fault © 2001 Cooper Bussmann, Inc. Selective Coordination - Insulated Case Circuit Breakers (See SPD) 2000A Insulated Case Circuit Breaker STD Is an Option - Allows breaker to delay opening Instantaneous Override built-in: may be as low as 12X the breaker rating Will often result in lack of coordination © 2001 Cooper Bussmann, Inc. Selective Coordination - Insulated Case Circuit Breakers (See SPD) 2000A Insulated Case with STD and Instantaneous Override and 100A Molded Case Thermal Magnetic Circuit breaker - NO Coordination in Short-Circuit Region (above 21,000A) 2000A 100A © 2001 Cooper Bussmann, Inc. Selective Coordination - LV Air Power Circuit Breakers (See SPD) Short Time Delay - Allows the fault current to flow for up to 30 cycles. Used to coordinate with downstream Subjects equipment to high mechanical and thermal stresses, often violating 110.10 Arc Flash/ Blast Risks Much Higher High Cost, Larger Equipment © 2001 Cooper Bussmann, Inc. Selective Coordination: Fuses © 2001 Cooper Bussmann, Inc. Selective Coordination:Fuses (See SPD) Time Current Curves © 2001 Cooper Bussmann, Inc. Selective Coordination:Fuses (See SPD) Selectivity Ratio Guide Based on Thermal Principle Based on I2t Not Melt Clear I2t melting > I2t Clearing 1200 A 600 A © 2001 Cooper Bussmann, Inc. Selective Coordination (See SPD ) Line Side Fuse Load Side Fuse LOW-PEAK® : LOW-PEAK® 2:1 Line:Load Ratio Selectivity Ratio Table Assures Coordination! No Plotting required! © 2001 Cooper Bussmann, Inc. Selective Coordination - Fuses 480V, 3 phase Example: Main: KRP-C 1200 SP Feeder: LPS-RK 200 SP Branch: LPS-RK-30 SP 1200 A MS B GFP 200 A MCC 30 A © 2001 Cooper Bussmann, Inc. Selective Coordination - Fuses Use Selectivity Table Main KRP-C 1200 SP Feeder LPS-RK 200 SP Branch LPS-RK 30 SP What happens: Branch Circuit Isca = 5000 A or 50,000A or 300,000A ? © 2001 Cooper Bussmann, Inc. Selective Coordination- Fuses Lineside KRP-C 1200SP to Loadside LPS-RK 200SP 1200/200 = 6:1 Table only need 2:1 Selective Coordination Lineside LPS-RK 200SP to Loadside LPS-RK 30SP 200/30= 6.67:1 Table only need 2:1 Selective Coordination © 2001 Cooper Bussmann, Inc. Selective Coordination NOT AFFECTED OPENS Fault © 2001 Cooper Bussmann, Inc. Are These Selectively Coordinated? Low Peak KRP-C 1000 SP Low Peak LPJ 200 SP Low Peak LPJ 20 SP Fault 10000 Amps © 2001 Cooper Bussmann, Inc. Are These Selectively Coordinated? Selectively Coordinated Low Peak KRP-C 1000 SP Low Peak KRP-C 1000 SP Low Peak LPJ 200 SP Low Peak LPJ 20 SP Fault 10000 Amps Low Peak LPJ 200 SP NOT AFFECTED Low Peak LPJ 20 SP OPENS Fault 10000 Amps © 2001 Cooper Bussmann, Inc. Are These Selectively Coordinated? 1000 A. CB IT @ 10 X 200 A. CB IT @ 10 X 20 A. CB IT @ 10X Fault 10000 Amps © 2001 Cooper Bussmann, Inc. Are These Selectively Coordinated? Not Coordinated 1000 A. CB IT @ 10 X 1000 A. CB IT @ 10 X 200 A. CB IT @ 10 X 200 A. CB IT @ 10 X 20 A. CB IT @ 10X NOT AFFECTED 20 A. CB IT @ 10X OPENS Fault 10000 Amps Fault 10000 Amps © 2001 Cooper Bussmann, Inc. The Issue: Lack of coordination takes out other loads 1000 A. CB IT @ 10 X 200 A. CB IT @ 10 X Unnecessary Blackout OPENS 20 A. CB IT @ 10X Fault 10000 Amps © 2001 Cooper Bussmann, Inc. Ejemplo de coordinación mostrando protección de los cables © 2001 Cooper Bussmann, Inc.