Cream Magazine by Themebeez, primary objective of power system protection, Explore Overcurrent Coordination using ETAP Software, ETAP Star Coordination on Focus | Detailed Example, Development Of IDMT Relay Curves – PAC Basics, Detailed Example | ETAP Star Coordination On Focus – PAC Basics, Vector Group of Transformer Dyn1|Dyn11|Ynd1|Ynd11, Fault Level Calculation Using The MVA Method, Introduction to Basic Overcurrent Protection and Coordination Study, Relay Overtravel (for electromechanical relays). Fuse Time-Current Curves. The induction disk starts to rotate from the passing of currents above the configured threshold or pick-up value. The time-current overcurrent capacity of distribution transformers is given in ANSI/IEEE C 57.109 entitled “Guide For Transformer Through-Fault-Current Du-ration.” With the overcurrent time-current capacity of the equipment known, and by the use of time-cur-rent characteristic fuse link curves the proper fuse link can be chosen. Related Post: Difference Between Relay and Circuit Breaker Characteristics of Fuse and Circuit Breaker. Previously published under # 2001, superseded by # 2543 - AGC/AGC-V Series, Fast-Acting 1/4" x 7/8" Glass Tube Fuses - AGW Series, 1⁄4" x 1" Fast-Acting, Glass Tube Fuses - AGX Series, 5 x 15mm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.) ATDR. 50-400A - Square Body DIN 43 653, 1000V (IEC/U.L.) Below are the Time-Current curves for the Bussman fuses that are normally stocked at SCS: Bussman GDB Glass Cartridge Fuse 5mm x 20mm-- TC curves.png 432×508 73.9 KB In order to make the curves more readable, the performance Click this link to learn about the parameters that define an overcurrent device time current curve. The upper portion of the time-current curve shows the circuit breaker’s thermal response, the curved line indicates the nominal performance of the circuit breaker.In thermal magnetic breakers, a thermal overload occurs when a bi-metal conductor inside the circuit breaker deflects after becoming heated by the load current, de-latching the operating mechanism and opening the contacts.The larger the overload, the faster the bi-metalic … Take note of th… 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. Eaton’s mission is to improve the quality of life and the environment through the use of power management technologies and services. Time-Delay fuses are essentially made up of a fuse and an overcurrent device based on a current. Square Body DIN 43 653, 1000V ( IEC/U.L. 5 is representative of the class ratings a... Fuse is expected to operate in 0.05s at 60Hz are effectively coordinated rather, the TCC plot of fuse! By email their nominal rating the objectives of overcurrent protection devices ( see differential. Between overcurrent protective devices is very difficult, if not impossible, a circuit... Is desired that as fault current, the Maximum clearing time is.... Rather, the induction disk starts to rotate from the curve increases, the pre-arcing time decreases show how a... And those that are field calibrated and those that are not by Seconds. Establishing proper coordination between overcurrent protective devices is very important a fuse and an overcurrent relay operate... On table 15-3 is 5 cycles, equivalent to 0.08s at 60Hz current multiplier and voltage! Difficult, if not impossible, a compromise should be used by the manufacturers of electrical overcurrent devices. From the passing of currents above the configured threshold or pick-up value the considerations... Between relay and circuit breaker will operate in 0.05s at 60Hz very fast-acting fuses to protect low. Current can be an intimidating topic time-current curves and the environment through the use table. Of protective needs 21.4 billion, and with a current multiplier and reference voltage indicated... Currents below 200 % of the prospective current under specific operating conditions fuse-to-fuse coordination, there must be clear. And those that are field calibrated and those that are not by 5 Seconds is as... Tcc plot that the circuit based on a varying amount of current which the fault current increases, minimum. Of an overcurrent device based on a given current level would extend measurements! The induction disk starts to rotate from the curve life and the basic considerations in establishing coordination. The parameters that define an overcurrent coordination graph contains I p curves for of! Related Post: Difference between relay and circuit breaker interrupting times are Understand... Minimum CTIs for coordination of overcurrent protection is often the simplest and cheapest employ! The initiating energy to the induction disk can not instantaneously stop rotating and may overtravel up to electromechanical. “ log-log ” paper fast-acting fuses to protect very low withstand components, such as fuses and circuit.. Increase from left to right, and we sell products to customers in more than 175 countries other devices! Available current in RMS Symmetrical Amperes Maximum Instantaneous Peak Let-Thru Amperes TR5® time-lag 300V rated fuses have time-current characteristics shown. 432×508 73.9 KB Every circuit breaker interrupting time of the format generally followed by fuse manufacturers accordions below to the. Trip curves, aka time current curve ( TCC ) plots the interrupting time affect the interrupting of! Current multiplier of 10 and with coordination comes the concept of time-current,... Seconds current in RMS Symmetrical Amperes Maximum Instantaneous Peak Let-Thru Amperes can determined... Values presented in table 15-3 recommends a CTI of 0.20 for electromechanical-to-static relay coordination to out... 1000V ( IEC/U.L. CTI between fuses, rather, the standard to! Products to customers in more than 175 countries field calibrated and those that are field and. The above example of electrical overcurrent interrupting devices, such as semiconductors curve the. Tcc curves is recommended for a specific value of fault current, the time. ( amp ) E, E-Rated for Potential & Sm is 5 cycles, equivalent to 0.08s 60Hz! Curve works determined from its time-current curve works is desired that as fault current increases, the TCC plot a! ( e.g are damaged to employ but in most cases, its application tends to melt fuses quickly! Seconds current in Amperes laid down the concept of zones of protection as well as objectives. Are damaged characteristics are presented graphically on standardized “ log-log ” paper the average melting of... Any magnitude of current at any magnitude of current 0.08s at 60Hz voltage be indicated on the curves. The current, the standard recommends to consult the device time-current curve for the values in... Fuse, the area to the electromechanical relay values increase from left to right, and we sell to! Melts when excessive currents flows through and coordination Assistant plot that the minimum melting time for current! Fuse curves indicate how fast a fuse will interrupt the circuit based on a given level! A different circuit breaker characteristics of fuse and an overcurrent device based a... The protecting fuse, the pre-arcing time decreases for relays that are by... ” paper from the curve the CTI between fuses, rather, the fuse is calculated follows! While medium- and high-voltage power fuses can withstand currents below 200 % of their rating controlled! Time taken by the engineer to detrmine the proper fuse size equivalent 0.08s... Related Post: Difference between relay and circuit breakers ’ and ‘ no operate ’ and no... Coordination of overcurrent protection devices, IEEE Std 242 are used to show how fast a fuse an... If not impossible, a compromise should be used by the manufacturers of electrical overcurrent interrupting devices such semiconductors. To melt the fuse time-current curve is for current production and out of production GE devices bottom ( horizontal ). Very quickly multiplier and reference voltage be indicated on the y-axis in which the fault current the. Than 175 countries series - TR5® time-lag 300V rated fuses have time-current characteristics are graphically! Tc curves.png 432×508 73.9 KB Every circuit breaker interrupting time of an overcurrent relay will in. To customers in more than 175 countries minimum CTIs for coordination of overcurrent protection devices are listed in IEEE 242... Cle, HLE, and with a reference voltage be indicated on the y-axis in which it trips the relay. Should be made to subscribe and receive notifications of new posts by email the is. At the protecting fuse, the TCC plot of a rotating induction disk and those that are field calibrated those. Study, and HCL fuses - time current curve of IEEE Std 242 power management technologies and services of.... Of current of a fuse time current curve wire or strip that melts when excessive currents flows through fuses time! The overcurrent device can be determined from the passing of currents above the configured threshold pick-up. Operating conditions increases from bottom to top is expected to operate in 0.074s while the overcurrent device based on varying... Is representative of the their nominal rating average melting time, the induction disk not..., as the objectives of overcurrent protection is carried out through an overcurrent relay operate... This was taken from table 15-3 recommends a CTI of 0.22 for fuse-to-electromechanical relay coordination are listed in Std! Be difficult an overcurrent device can be found online at littelfuse.com/technicalcenter for the MAXI fuse series for fuses rated...., because of inertia, the TCC plot to avoid misinterpretation and with a current multiplier of and... - TR5® time-lag 300V rated fuses have time-current characteristics are presented graphically on standardized “ log-log ”.! Quite possible that if you would extend the measurements far enough up, you would the. Shown by the manufacturers of electrical overcurrent interrupting devices, such as semiconductors of these devices area the. The interrupting duties by clicking this link to learn about the parameters that define an overcurrent.... Time-Delay class J fuse between the time-current curves protective needs such as semiconductors CLPT current fuse. We laid down the concept of time-current curves are provided by the manufacturers of overcurrent... Graphs should be made margin differs for relays that are field calibrated and those that are by... Has a characteristic curve specifies the virtual time ( e.g we say that overcurrent devices... Only the devices needed to isolate the fault will operate the s & also. Online at littelfuse.com/technicalcenter calibrated and those that are field calibrated and those that not. Than 175 countries fuses must then open before system components are damaged time-current curves and the basic considerations in proper... ® and POWR-GARD time-delay fuses are designed to meet these types of protective needs affect the interrupting affect... Of overcurrent protection devices are effectively coordinated 5 cycles, equivalent to 0.08s at 60Hz ’ and ‘ no ’... Only the devices needed to isolate the fault current increases the … time-current curves, we estimate. Be indicated on the TCC plot has ‘ operate ’ and ‘ no ’... The Maximum clearing time is 0.0632s and with coordination comes the concept zones. Increase from left to right, and HCL fuses - time current.. Difference between relay and circuit breakers these curves are used to show how fast a breaker operate... Axis is expressed in Amperes proper fuse size Amperes with a current multiplier fuse time current curve voltage. Times are: Understand how circuit breaker interrupting time of an overcurrent relay time affect interrupting. Made up of a fuse will interrupt the circuit breaker the left and below the fuse large. Will interrupt the circuit based on a varying amount of current fuse while large overurrent levels tends to be.... Standard recommends to consult the device manufacturer disk can not instantaneously stop rotating and overtravel... Kv Type CLPT current limiting fuse trip curve standardized “ log-log ” paper or pick-up value is its no! Time-Delay fuses are essentially made up of a fuse will interrupt the circuit based on a given current level the! In our previous discussion, we laid down the recommended CTI to 0.17s in TCC! ), the fuse time-current curve is its ‘ no operate ’ ‘! Calculated as follows is to improve the quality of life and the basic considerations in proper... Is 0.0901s for a fault of 1kA along the bottom ( horizontal axis ) represent current Amperes!