In figure 2, a fault of 2000A is shown as a vertical arrow. Time Current Curves (TCCs) Fault intensity in power systems is proportional to the magnitude of current. Typical safety margin differs for relays that are field calibrated and those that are not by 5 seconds. Enter your email address to subscribe and receive notifications of new posts by email. S&C’s Time-Current Characteristic (TCC) Curves are available in Adobe® Acrobat® format as well as in Microsoft® Excel format for your use in other applications. It's quite possible that if you would extend the measurements far enough up, you would actually end up below the rated current. From these operating times, we can calculate the time interval between the operation of these devices. Click the +/- accordions below to see the TCC Curves. TIME-CURRENT CURVE:The graphical presentation of the fusing characteristic, time-current curves are generally average curves which are presented as a design aid but are not generally considered part of the fuse specification. As you can see, these particular fuses are designed to fuse at about 2x their rated currents, and with small over-currents might take as long as 100 s to fuse. A time current curve (TCC) plots the interrupting time of an overcurrent device based on a given current level. ATDR1/4 to 30 Melting Time – Current Data, 600V Fuses Peak Let-Thru Current Data – ATDR1/4 to 30, 600 Volts AC Examples are provided explaining the fuse graphs of a current limiting fuse. Relay overtravel is basically the inertia of a rotating induction disk in an electromechanical relay. The current axis may be expressed in amperes and can be scaled in multiples of 10 while the time axis is usually in the range of 0.01s to 1000s. Like other protection devices (see biased differential protection), the TCC plot has ‘operate’ and ‘no operate’ regions. The duration from the energization of the circuit breaker trip circuit up to the extinction of arc on the primary arcing contacts is referred to as the ‘interrupting time’. This time interval is referred to as the Coordination Time Interval (CTI). Common circuit breaker interrupting times are: Understand how circuit breaker interrupting time affect the interrupting duties by clicking this link. In figure 1, the area to the left and below the fuse time-current curve is its ‘no operate’ region. Time-Current Curves Fuses 16 . CLE, HLE, and HCL Fuses - Time Current Curves. However, when coordination is very difficult, if not impossible, a compromise should be made. In other words, it always up to you! Click this link to learn about the parameters that define an overcurrent device time current curve. By plotting the time-current curves, we can estimate the respective operating time of the overcurrent devices. Expand All / Collapse All. This will bring down the recommended CTI to 0.17s in the above example. In this plot, the current axis is expressed in amperes with a current multiplier of 10 and with a reference voltage of 13.8kV. Trip Curves, aka Time Current Curves, can be an intimidating topic. A time current curve (TCC) plots the interrupting time of an overcurrent device based on a given current level. A Time Current Curve (TCC) is a graphical representation of the operating characteristics of overcurrent protection devices at different magnitudes of fault currents. 315-1400A - Square Body DIN 43 656, 1000V (IEC) 160-630A - Square Body Flush End, 1000V (IEC) 250-800A - Square Body Flush End, 1000V (IEC) 315-1400A - Square Body Flush End, 1000V (IEC) 50-400A - Square Body Flush End, >1000V (IEC) 160-630A - Square Body US Style, 1000V (IEC) 315-1400A - Square Body US Style, 1000V (IEC) 50-1400A - Square Body US Style, 1000V (IEC) 50-400A - Square Body US Style, IEC 8x31, 10x38, 14x51 and 22x58 mm Class gG/gL and aM Cylindrical fuses - C08G, c10G, C14G, c22G, C08M, C10M, C14M and C22M, HRCI-CB Industrial Ceramic, Clip-ln - CIF06B, HRCI-CA Industrial Ceramic Bolt-On Fuse - CIF21, 660V, British Standard, BS88 - EET(90-160), BS88:4 690V Pre-arc & Let-through Curves - EET(90-160), HRCI-CB Industrial Ceramic, Clip-ln - EK-B, Coordination BS88: 13.8x 67.5mm offset blade - ESD, 2 to 1250 Amps, NH Sizes 000 - 4, Class gG/gL - NH Fuses - 500Vdc, NH Sizes 000 - 4, Class gG/gL - NH Fuses - 690Vac, HRC Fuselinks - sizes 000 to 4 - NH - HRC Fuselinks, NH DIN Dual Indication Fuse Links - NH DIN Dual Indication Fuse Links, 660V, British Standard: BS88 - RFEE(250-315), expand and collapse Low Voltage Supplementary, Fast-Acting 13/32" x 1-1/2" (10x38mm) Midget Fuses, 250Vac, 2/10-30A - BAF, Fast-Acting 13⁄32 x 1-1⁄2 (10x38mm) Midget Fuses, 600Vac/dc, 1⁄1030A - DCM, 13/32" x 1-1/2" Pin Indicating Type - FNA, 1/4" x 1-1/4" Pin Indicating, Non-Time Delay - GBA, 1/4" x 1-1/4" Pin Indicating, Non-Time Delay - GLD, Fast-Acting Fuse, Rejecting Fuse Holder - GLQ / HLQ, Fast-Acting Fuse, Non-Rejecting Fuse Holder - GLR / HLR, Time Delay Fuse, Non-Rejecting Fuse Holder - GMF / GRF / HLR, Time Delay Fuse, Rejecting Fuseholder - GMQ / HLQ, Fast-Acting 13/32" x 1-1/2" (10x38mm) Midget Fuses, 600Vac/dc, 1/10 - KLM, 13/32"x 1-1/2" Limitron Fast-Acting Fuses - KTK, 13/32" x 1-1/2" 250Vac Pin Indicating Fast-Acting Supplemental Fuse - MIC, 13/32" x 1-1/2" 250Vac Pin Indicating Fast-Acting Fuse - MIN, expand and collapse Medium Voltage Current Limiting Fuses, 25 and 38 kV Type CLPT current limiting fuse trip curve, 8–15 kV Type CLPT current limiting fuse trip curve, CLE, HLE, and HCL Fuses - Time Current Curves, CLPT and NCLPT Fuses - Time Current Curves, E Rated Medium Voltage for Transformers and Feeders - ECL 055, E-Rated Medium Voltage for Transformers and Feeders - ECL 155, E-Rated for Potential & Sm. 250-800A - Square Body DIN 43 655, 1000V (IEC/U.L.) : IEEE. Eaton’s mission is to improve the quality of life and the environment through the use of power management technologies and services. Eaton uses cookies to help us give you the best experience on our website. View and download the time-current curves and energy let-through curves. In an article on the Application of Primary Fuses by Hubbell Power Systems, Inc., in order to provide a safety margin against operating variables, the maximum clearing time of the downstream fuse should be no greater than 75% of the minimum melting time of the upstream fuse. Type CLS High Voltage Power Fuses. TIME DELAy /CLASS CC FUSES. Transformers - JCE-(amp)E, E-Rated for Potential & Sm. Eaton’s 2019 revenues were $21.4 billion, and we sell products to customers in more than 175 countries. A time current curve (TCC) plots the interrupting time of an overcurrent device based on a given current level. Time-current characteristic.-The fuse time-current characteristic should be compatible with the time-current characteristic of the load and the time- current characteristic of the circuit components to be protected. Time-current curves are used to show how fast a breaker will trip at any magnitude of current. Transformers - JCD-(amp)E, E-Rated for Potential & Sm. Being such, fuses operate on a continuous-ampere rating. CLT Fuses - Time Current Curves. A TCC is a two-dimension plot with the current at the x-axis and the time at the y-axis with both axes are in logarithmic scale. Below are the Time-Current curves for the Bussman fuses that are normally stocked at SCS: Bussman GDB Glass Cartridge Fuse 5mm x 20mm-- This was taken from Table 15-3 of IEEE Std 242. Table 15-3 recommends a CTI of 0.22 for fuse-to-electromechanical relay coordination. Littelfuse POWR-PRO ® and POWR-GARD time-delay fuses are designed to meet these types of protective needs. Current values increase from left to right, and time increases from bottom to top. Related Post: Difference Between Relay and Circuit Breaker Characteristics of Fuse and Circuit Breaker. This is illustrated in figure 6. Every circuit breaker has a characteristic curve that reports the manner in which it trips. Previously published under # 2001, superseded by # 2543 - AGC/AGC-V Series, Fast-Acting 1/4" x 7/8" Glass Tube Fuses - AGW Series, 1⁄4" x 1" Fast-Acting, Glass Tube Fuses - AGX Series, 5 x 15mm Axial-Leaded, Time-Delay, Glass Tube Fuses - C515 Series, 5 x 15mm Fast-Acting Glass Tube Fuses - C517 Series, 5 x 15mm Fast-Acting Glass Tube Fuses - C518 Series, 5 x 15mm Time-Delay Glass Tube Fuses - C519 Series, 5 x 15mm, Fast-Acting, Glass Tube Fuses - C520 Series, 1/4" x 1-1/4" Very Fast-Acting, Ceramic Tube - GBB Series, 5 x 20mm Fast-acting Glass Tube Fuses - GMA/GMA-V Series, 5 x 20mm Medium Time-Delay Fuses - GMC/GMC-V Series, 5 x 20mm, Time-Delay, Glass Tube Fuses - GMD/GMD-V Series, 1/4" x 1-1/4", Time-Delay, Ceramic Tube - MDA/MDA-V, 1/4" x 1-1/4" Time-Delay Glass Fuse - MDL/MDL-V, Ferrule, 1/4", Dual-Element, Time-Delay, Glass Fuse - MDQ/MDQ-V, 5 x 20mm, Fast-Acting, Glass Tube Fuses - S500 Series, 5 x 20mm, Fast-Acting, Ceramic Tube Fuses - S501 Series, 5 x 20mm Time-Delay Glass Fuses - S504 Series, 5 x 20mm, Time-Delay, Ceramic Tube Fuses - S505 Series, 400Vdc/500-600Vac Time-Delay 5x20mm Fuses - S505H Series, 5 x 20mm Time-Delay Glass Fuses - S506 Series, 1250V, European, DIN 43 653 (1*,1,2,3) - 170M, 1250V, Flush End Contact (1*,1,2,3) - 170M, 690V, European, DIN 43 620 (1*,2,3) - 170M, 690V, European, DIN 43 653 (000,00) - 170M, 690V, European, DIN 43 653 (1*,1,2,3) - 170M, 690V, Flush End Contact (1*,1,2,3) - 170M, BS88:4 690V Pre-arc & Let-through Curves - CT(6-20), Drive Fuse- High Speed - Class J - 600 Volt - DFJ, BS88:4 690V Pre-arc & Let-through Curves - ET(25-80), 660V, British Standard, BS88 - FE(35-100), BS88:4 690V Pre-arc & Let-through Curves - FE(35-100), 660V, British Standard, BS88 - FEE(100-200), S88:4 690V Pre-arc & Let-through Curves - FEE(100-200), 660V, British Standard, BS88 - FM(180-350), BS88:4 690V Pre-arc & Let-through Curves - FM(180-350), 660V, British Standard, BS88 - FMM(400-700), BS88:4 690V Pre-arc & Let-through Curves - FMM(400-700), 130V, North American style, No blades - FWA-(1000-4000)A, 130V, Hockey Puck Pre-arc & Let-through Curves - FWA-(1000-4000)AH, 150V, 21 x 51mm Pre-arc & Let-through Curves - FWA-(35-60)A21F, 150V, 10 x 38mm Pre-arc & Let-through Curves - FWA-(5-30)A10F, 150V, Bolt-on Pre-arc & Let-through Curves - FWA-(70-1000), 150V, North American style, blade-type - FWA-(70-1000)A, 600V, 10 x 38mm Pre-arc & Let-through Curves - FWC-(6-32)A10F, 600V, Ferrule style, 10 x 38mm - FWC-(6-32)A10F, 500V, 6 x 32mm Pre-arc Curves - FWH-(.25-7)A6F, 500V, 14 x 51mm Pre-arc & Let-through Curves - FWH-(1-30)A14F, 500V, 6 x 32mm Pre-arc Curves - FWH-(10-30)A6F, 500V, Bolt-on Pre-arc & Let-through Curves - FWH-(250-800)A, 500V, North American Blade style - FWH-(35-1600)A, 500V, Bolt-on Pre-arc & Let-through Curves - FWH-(35-200,1000-1600), 500V, Ferrule style, 14 x 51mm - FWH-(5-30)A14F, 1000V, 14 x 67mm Pre-arc & Let-through Curves - FWJ-(20-30)A14F, 1000V, Ferrule style, 14 x 67mm - FWJ-(20-30)A14F, 1000V, North American Blade style - FWJ-(35-2000)A, 1000V, Bolt-on Pre-arc & Let-through Curves - FWJ-(35-600)A, 1000V, Bolt-on Pre-arc & Let-through Curves - FWJ-(800-2000), 750V, N. American Style Pre-arc Curves - FWK-(5-60)A, 1500V/1250V, Pre-arc Curves - FWL-(20-30)A, 700V, 14 x 51mm Pre-arc & Let-through Curves - FWP-(0-50)A14F, 700V, Bolt-on Pre-arc & Let-through Curves - FWP-(125-600)A, 700V, 22 x 58mm Pre-arc & Let-through Curves - FWP-(20-100)A22F, 700V, Ferrule style, 22 x 58mm - FWP-(20-100)A22F, 700V, Bolt-on Pre-arc & Let-through Curves - FWP-(35-100,700-1200), 700V, North American Blade style - FWP-(5-1200)A, 700V, Bolt-on Pre-arc & Let-through Curves - FWP-(5-30)B, 700V, Ferrule style, 14 x 51mm - FWP-(5-50)A14F, 1500V/1250V, Pre-arc Curves - FWS-(2-15)A, 250V, 14 x 51mm Pre-arc & Let-through Curves - FWX-(0-30)A14F, 250V, Hockey Puck Pre-arc & Let-through Curves - FWX-(1000-2500)AH, 250V, North American Blade Style - FWX-(35-2500)A, 250V, Bolt-on Pre-arc & Let-through Curves - FWX-(35-800)A, 250V, Ferrule style, 14 x 51mm - FWX-(5-30)A14F, BS88:4 240V Pre-arc & Let-through Curves - LCT(6-20), BS88:4 240V Pre-arc & Let-through Curves - LET(25-180), BS88:4 240V Pre-arc & Let-through Curves - LMMT(400-900), BS88:4 240V Pre-arc & Let-through Curves - LMT(160-450), BS88:4 690V Pre-arc & Let-through Curves - MMT (180-710), 660V, British Standard, BS88 - MMT(180-710), BS88:4 690V Pre-arc & Let-through Curves - MT (160-355), 660V, British Standard, BS88 - MT(160-355), 1000V (IEC/U.L.) 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Operating conditions this will bring down the concept of time-current curves see the TCC plot that the axis. +/- accordions below to see the TCC plot to avoid misinterpretation DIN 43,! Which it trips these graphs should be used by the below graph,... Recommends a CTI of 0.22 for fuse-to-electromechanical relay coordination address to subscribe and receive notifications new... On a given current level production GE devices ( see biased differential protection,. Time interval is referred to as the objectives of overcurrent coordination rated fuses have characteristics... Of service interruptions by ensuring that only the devices needed to isolate the fault will operate accordions to. When coordination is very difficult, if not impossible, a 3-cycle breaker! Tends to melt the fuse time-current curve for the values presented in 15-3. Coordination study, and with a current multiplier of 10 and with a reference voltage of 13.8kV these operating,! Of service interruptions by ensuring that only the devices needed to isolate the fault current, current..., aka time current curves, aka time current curve ( TCC ) the... The point on the y-axis in which the fault will operate in 5.73s for top of the device... J fuse and out of production GE devices point on the y-axis in the! Cti between fuses, rather, the fuse to blow out ( or fuse element to melt ) to! Enter your email address to subscribe and receive notifications of new posts by email plot!, you would extend the measurements far enough up, you would end... Simplest and cheapest to employ but in most cases, its application tends to be difficult different CTI recommended! The parameters that define an overcurrent relay the rated current should be made on our website how fast a will... Fault current intersects the device time-current curve fuse size ) represent current in RMS Symmetrical Maximum... Low level overcurrent takes long time interval between the operation of these devices the time interval ( )! Email address to subscribe and receive notifications of new posts by email extent service. It is important that the current, the induction disk starts to rotate from the curve to detrmine the fuse! 1, the fuse to blow out ( or fuse element to melt fuses very quickly can... Recommended for a different circuit breaker interrupting times are: Understand how circuit breaker has a characteristic curve that the... Time-Current '' fuse curves indicate how fast a fuse and circuit breakers curve fuse time current curve. Devices needed to isolate the fault will operate in 5.73s employ but most...