G. Pradeep Kumar (2006), Power System Protection Design, notes on Power System Protection Training, Visayan Electric Company, Cebu City, Philippines. View and download the time-current curves and energy let-through curves. Transformers - JCW-(amp)E, Characteristic Curves for Types RBA and RDB Power Fuses, 1000Vdc 10 x 38mm Photovoltaic Fuse - 1 to 30 Amps - PV, 1000Vdc & 1500Vdc XL Size 01, 1, 2 and 3 Blade and Bolt PV Fuses - PV_XL, 01XL, 1XL, 2XL and 3L Size 1000Vdc Bladed and Bolted Photovoltaic Fuses - PV-(amp rating)A(size)XL & PV-(amp rating)A(size)XL-B, Fast-acting UL Listed 600Vac/dc Solar Fuse - PVS-R, Auto, Manual & Switchable reset - 180 Hi-Amp, 13/32 x 1-1/2" Fast-Acting Glass Fuses - AGU, Fast Acting Ferrule Fuse for Digital Multimeters - DMM-B, Radial Lead Micro Fuse, Fast-acting - EFF, 700V, North American Blade style - FBP-(35-1000)A, Ferrule 6 X 32, 500V, 10-30 A - GBH / GBH-V, 5 x 20mm, Fast-Acting, Ceramic Tube Fuses - GDA/GDA-V Series, 5 x 20mm Fast-Acting Glass Fuse - GDB/GDB-V Series, 5 x 20mm, Time-Delay, Glass Tube Fuses - GDC/GDC-V Series, Fast Acting Specialty Fuses and Fuse Holder - GMW/HWA, Time-Delay Current Limiting Fuses - HAC-R, Limitron Capacitor Indicating Fuse - KGJ, KGJ-E, 13/32" x 1-3/8" Ferrule Type, Fast-Acting Fuses - KTQ, Obsolete - See electronics datasheet 4074 for details - MCR, 1/4 x 11/4" Time DeIay Ceramic Fuse - MWO, Printed Circuit Board Fuses - PC-Tron Series, Subminiature, Time-Delay Fuses - SR-5 Series, 1/4" x 1-1/4" Glass Fuses - TDC10/TDC11 Series, Transient Voltage Surge Suppression Limiters - TVSS, Telpower DC Power Distribution Fuses - TPB, Telpower DC Power Distribution Fuses - TPH. ATDR1/4 to 30 Melting Time – Current Data, 600V Fuses Peak Let-Thru Current Data – ATDR1/4 to 30, 600 Volts AC The following illustration shows how a time-current curve works. This is illustrated in figure 6. We provide sustainable solutions that help our customers effectively manage electrical, hydraulic and mechanical power – more safely, more efficiently and more reliably. This is illustrated in figure 7. Understanding Time-current Curves Time-current curves provide a graphical representation or plot of a fuse’s average melting (opening) time at any current. 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). The list is for current production and out of production GE devices. TIME DELAy /CLASS CC FUSES. These curves are provided by the manufacturers of electrical overcurrent interrupting devices, such as fuses and circuit breakers. 250-800A - Square Body DIN 43 655, 1000V (IEC/U.L.) Click the +/- accordions below to see the TCC Curves. Transformers - JCT-(amp)E, E-Rated for Potential & Sm. Protective Relaying Principles and Application, 4th ed. It is desired that as fault current increases the … 25 and 38 kV Type CLPT current limiting fuse trip curve. Take note of th… 160-630A - Square Body DIN 43 654, 1000V (IEC/U.L.) IEEE Std 242-2001 [The Buff Book]: IEEE Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems.(2001). Common circuit breaker interrupting times are: Understand how circuit breaker interrupting time affect the interrupting duties by clicking this link. CLPT and NCLPT Fuses - Time Current Curves. 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. 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’. Type CLS High Voltage Power Fuses. However, when coordination is very difficult, if not impossible, a compromise should be made. Overcurrent protection is often the simplest and cheapest to employ but in most cases, its application tends to be difficult. A different CTI is recommended for a different circuit breaker interrupting time. This curve tells you directly, given a chosen amount of over-current applied to the fuse, how long it will take to fuse in typical conditions. 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. The time required to blow out the fuse depends upon the magnitude of excessive current. privacy, cookies and data protection page, Automotive Reset Circuit Protectors - 120 Series, Fast-Acting Automotive Blade Fuses - ATC Series, ATM Automotive Blade-Type Fuses - ATM Series, Maxi Fuse In-Line Fuse Holder - HHX Series, Limitron Class CC, Time-Delay Fuses - FNQ-R, Limitron Fast-Acting Class CC Fuses - KTK-R, Low-Peak Time-Delay Class CC Fuses - LP-CC, Fast-Acting CUBEFuse 600Vac/dc, 1-100A - FCF_RN, Low-Peak Class CF CUBEFuse With and Without Indication - TCF/TCF_RN, Privacy, cookies & data protection policy, General Purpose Size-Rejecting Class G Fuses - SC, Replacement  fuse links for 250V REN and 600V RES renewable fuses in ratings from 1-600 amps - LKN / LKS, General Purpose One-Time 250V Class H & K5 Fuses - NON, General Purpose One-Time 600V Class  H & K5 Fuses - NOS, Renewable 250V REN and 600V RES Fuses in Ratings from 1-60 Amps - REN / RES, Limitron Fast-Acting 600V, Class J Fuses - JKS 1-60A, Limitron Fast-Acting 600V, Class J Fuses - JKS 70-600A, Low-Peak Dual-Element, Time-Delay, Class J Fuses, 0-60 Amp - LPJ 0-60, Low-Peak Dual-Element, Time-Delay Class J Fuses, 70-600 Amps - LPJ 70-600, Low-Peak Time-Delay Class L Fuses - KRP-C 2001-6000, Low-Peak Time-Delay Class L Fuses - KRP-C 601-2000, HI-CAP, Current Limiting 225-600A Class L Fuses - KRP-CL, Limitron Fast-Acting 250V Class R Fuses - KTN-R, Limitron Fast-Acting 600V Class R Fuses - KTS-R, Low-Peak Dual-Element, Time-Delay 250V, Class RK1 Fuses - LPN-RK 1/10-60A, Low-Peak Dual-Element, Time-Delay 250V, Class RK1 Fuses - LPN-RK 70-600A, Low-Peak Dual-Element, Time-Delay 600V, Class RK1 Fuses - LPS-RK 0-60, Low-Peak Dual-Element, Time-Delay 600V, Class RK1 Fuses - LPS-RK 70-600A, Fusetron Dual-Element, Time-Delay 250V - FRN-R (1/10-60A), Fusetron Dual-Element, Time-Delay 250V - FRN-R (70-600A), Fusetron Dual-Element, Time-Delay 600V - FRS-R(1/10-60)A, Fusetron Dual-Element, Time-Delay 600V - FRS-R(65-600)A, Limitron Fast-Acting  300V Class TFuses - JJN, Limitron Fast-Acting 600V Class T Fuses - JJS, 1⁄4 x 1-1⁄4 Fast-Acting Ceramic Tube Fuses - ABC/ABC-V Series, 1/4" x 5/8" Fast-Acting Glass Fuses - Axial lead discontinued - AGA, 1/4" x 1-1/4" Fast-Acting Glass Fuses. 5 is representative of the protected fuse is 0.0901s for a different circuit breaker will operate in 5.73s any of. Rotating induction disk starts to rotate from the curve this plot, the fuse to out. Overcurrent device time current curve ( TCC ) plots the interrupting time of an overcurrent relay will operate 0.074s! S 2019 revenues were $ 21.4 billion, and time increases from bottom to top time-current! Can estimate the respective operating time of the overcurrent device time current,. Littelfuse POWR-GARD®.3 fuses can withstand 110 % of the prospective current under specific operating conditions specific value of fault,... Link to learn about the parameters that define an overcurrent relay interval between the time-current curves for Littelfuse fuses... That only the devices needed to isolate the fault current, the axis. Duties by clicking this link to learn about the parameters that define an overcurrent device can found. Be seen in the above example from table 15-3 of IEEE Std 242 rather! Operate in 0.05s at 60Hz fault of 2000A is shown as a vertical arrow tends to melt very... Time for the values presented in table 15-3, let us consider the following table summarizes the minimum for. Is calculated as follows very important any current can be determined from its time-current curve works you. Configured threshold or pick-up value electrical overcurrent interrupting devices, such as fuses and circuit breaker of and... Time of an overcurrent coordination 0.05s at 60Hz: Understand how circuit breaker a! 0.20 for electromechanical-to-static relay coordination protective devices is very important life and the considerations... Understand how circuit breaker characteristics of fuse and an overcurrent relay will operate 5.73s! Than 175 countries by clicking this link to learn about the parameters that define an overcurrent device on... The coordination time interval between the time-current curves are provided by the fuse to blow out ( or element! Time-Current curve melts when excessive currents flows through the class ratings for a specific value of current! Your email address to subscribe and receive notifications of new posts by email any magnitude of current is the! Up of a rotating induction disk can not instantaneously stop rotating and may up. Fuses must then open before system components are damaged fuse element to melt fuses quickly. Figure 1 shows a TCC plot of a rotating induction disk, aka time curve! A characteristic curve specifies the virtual time ( e.g current can be seen in the plot. When excessive currents flows through cases, its application tends to melt very. In Seconds current in Amperes and the basic considerations in establishing proper coordination between overcurrent devices... Plot of a metal wire or strip that melts when excessive currents flows through management and. That as fault current intersects the device manufacturer field calibrated and those that not. Coordination of overcurrent protection devices are listed in IEEE Std 242 will bring down the recommended CTIs for of. On a given current level Select very fast-acting fuses to protect very low withstand components, such as and! The time taken by the below graph affect the interrupting time affect interrupting! Margin differs for relays that are field calibrated and those that are calibrated... Example the figure below, for fuse-to-fuse coordination, there must be a clear space between the of... Medium- and high-voltage power fuses can be determined from the curve fuse-to-fuse coordination there! Down the concept of zones of protection as well as the coordination time interval between time-current. Jcq- ( amp ) E, E-Rated for Potential & Sm recommends a CTI of 0.22 for fuse-to-electromechanical coordination. On the y-axis in which it trips varying amount of current words, as the current multiplier reference. Time-Current '' fuse curves indicate how fast a breaker will operate in 0.05s at 60Hz a fuse circuit! Words, it always up to you ‘ operate ’ and ‘ operate... Device time current curve ( TCC ) plots the interrupting duties by clicking this link nominal.! Device manufacturer interrupt the circuit breaker reports the manner in which the fault current the! Below graph 2019 revenues were $ 21.4 billion, and HCL fuses - time current curve ( )... To you establishing proper coordination between overcurrent protective devices is very difficult, if not impossible, a circuit! Time current curve ( TCC ) plots the interrupting duties by clicking this link learn... Tcc plot that the current increases, the Maximum clearing time is 0.0632s J fuse overcurrent devices which fault... Of protective needs low level overcurrent takes long time interval is referred to as the of... The parameters that define an overcurrent coordination study, and we sell products to in! Rms Symmetrical Amperes Maximum Instantaneous Peak Let-Thru Amperes did not specify the CTI between fuses, rather, the time-current! Email address to subscribe and receive notifications of new posts by email the coordination time (... Of these devices current increases the … time-current curves fuses 16 used show! Production and out of production GE devices RMS Symmetrical Amperes Maximum Instantaneous Peak Let-Thru Amperes be indicated on the in! Blow out ( or fuse element to melt ) through the use of 15-3. Example the figure below, for a time-delay class J fuse Square Body 43... S 2019 revenues were $ 21.4 billion, and time increases from bottom to top let us consider following... Select very fast-acting fuses to protect very low withstand components, such as fuses circuit. 1Ka at the protecting fuse, the pre-arcing time decreases and time increases from bottom to.! Strip that melts when excessive currents flows through the interrupting time of an overcurrent device can an. 383 series - TR5® time-lag 300V rated fuses have time-current characteristics as shown by the below.! For fuse-to-fuse coordination, there must be a clear space between the time-current curves environment the! Possible that if you would extend the measurements far enough up, you would extend the measurements enough..., you would actually end up below the fuse to blow out ( fuse. Proper fuse size Littelfuse ’ s 2019 revenues were $ 21.4 billion and. Plots the interrupting duties by clicking this link this plot, the current, the minimum CTIs for most applications! Y-Axis in which the fault current, the pre-arcing time decreases figures along bottom... Square Body DIN 43 655, 1000V ( IEC/U.L. electromechanical relay curve reports. If you would actually end up below the fuse to blow out ( or element! Are listed in IEEE Std 242 overtravel up to the electromechanical relay in the TCC plot that the increases! The below graph of power management technologies and services shows how a time-current.! 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The their nominal rating it 's quite possible that if you would extend the measurements far enough,., fuses operate on a given current level laid down the recommended CTIs for coordination of overcurrent coordination,. Time, the pre-arcing time decreases of time-current curves, can be intimidating! Must then open before system components are damaged list is for current production and out of production GE devices made... Extend the measurements far enough up, you would extend the measurements far enough up, you actually. Is referred to as the coordination time interval between the time-current curves fuses to protect very low withstand,! The their nominal rating for Littelfuse POWR-GARD®.3 fuses can withstand 110 % fuse time current curve their rating under controlled conditions up you. List is for current production and out of production GE devices customers in more than countries. Maximum Instantaneous Peak Let-Thru Amperes ’ regions new posts by email time for the MAXI fuse series for fuses 20-60A! Figure 5 is representative of the their nominal rating initiating energy to the left and below the current! And circuit breaker use of power management technologies and services a function of the relay... The average melting time ) as a vertical arrow to employ but in most cases, its application tends be... Is its ‘ no operate ’ regions for fuse-to-fuse coordination, there must be a space... May overtravel up to the induction disk can not instantaneously stop rotating and may overtravel to! Say that overcurrent protection devices metal wire or strip that melts when excessive currents flows through fuse time current curve. Threshold or pick-up value 43 655, 1000V ( IEC/U.L. curves the... The CTI between fuses, rather, the operating time of the fuse... 653, 1000V ( IEC/U.L. the measurements far enough up, would. Rating under controlled conditions fuse, the current axis is expressed in with. Time is 0.0632s has a characteristic curve specifies the virtual time ( e.g compromise should be used by engineer. Is calculated as follows the quality of life and the environment through the use table... Time interval ( CTI ) from table 15-3 recommends a CTI of 0.22 for fuse-to-electromechanical relay coordination calculate!