The x-axis or horizontal axis of the Time/PSM graph represents PSM and Y-axis, or vertical axis represents the time of operation of the relay. If the relay is rated with 1 A, the normal pick up current of the relay is 1 A and it should be equal to secondary rated current of current transformer connected to the relay. It is essential to provide suitable protection schemes for distribution networks to ensure that faults are quickly remedied. Such terms are. Mohammed Tawfeeq 011 Overcurrent Relay Setting 50 Elements: Pickup Setting 51 Elements Pickup setting Time delay setting definite time: time setting Overcurrent Relay & Earth Fautt Relay Concept, Setting Calculation, Characteristics and Application in Power System explained in detail What is an Overcurrent Relay? Hence, fault current in the CT secondary, i.e., in the relay coil is, 1000 × 1/200 = 5A Problem 1: – Determine the time of operation of a 5-ampere, 3-second over current relay having a current setting of 125% and a time setting, multiplier of 0.6 connected to supply circuit through a 400/5 current transformer when the Similarly, if active turns of the relay coil are increased, then proportionately reduced current is required to produce same desired deflecting force. 9. GlobalSpec may share your personal information and website activity with our clients for which you express explicit interest, or with vendors looking to reach people like you. The current setting of overcurrent relay is generally ranged from 50 % to 200 %, in steps of 25 %. The force applied to the relay’s moving parts for changing the normal position of the contacts is called deflecting force. In addition to setting criteria guide lines prepared by Subcommittee on relay/protection under Task Force for Power System Analysis under Contingencies for 220kV, 400kV and 765kV transmission lines, the Subcommittee has prepared model setting calculation documents for Say a relay has a time setting 0.1 and you have to calculate actual time of operation for PSM 10. Companies affiliated with GlobalSpec can contact me when I express interest in their product or service. In all electrical relays, the moving contacts are not free to move. When calculating the fault currents, the power system is assumed to be in its normal operating state. This reference guide uses detailed examples and exercises to explain the co-ordination and inception of protection schemes. This should be 0.50 - 15.00 for U.S. curves and 0.05 - 1.00 for IEC curves. This feature is necessary to ensure discrimination on very heavy fault current flowing through sound feeders. Overcurrent Relay Setting Calculation Xls Author vps1.nordictrack.vn-2020-12-23-21-40-42 Subject Overcurrent Relay Setting Calculation Xls Keywords overcurrent,relay,setting,calculation,xls Created Date 12/23/2020 9:40:42 PM Relay operate immediately when overcurrent is present. The adjustment of traveling distance of an electromechanical relay is commonly known as time setting. When electromechanical relays were more popular, the overcurrent protection was made up from separate single-phase units. Dominik Pieniazek, P.E. Protection Schemes and Substation Design Diagrams, Chapter 14: ACCESS You may withdraw your consent at any time. BEST IDEAS. Again the deflecting force of the coil is proportional to its number of turns and the current flowing through the coil. Generator Protection – Setting Calculations The relay secondary current : = 16004/RC = 16004/1600 = 10 A Set the overcurrent pickup at 50% of this value = 5 A For situations when lines out of the plant are removed from service Use of Digital Logic in Numerical Relaying, 5.11: The number of active turns in the coil can be changed by inserting a plug in different points in the bridge. The same procedure can be applied to multiple circuit arrangements. Setting overcurrent relays involves selecting the parameters that define the required time/current characteristic of both the time-delay and instantaneous units. From current setting we calculate the trick current of the relay. An error occurred while processing the form. 3.5.3 Relay 'resting Method 27 CALCULATION A N D RESULT 4.1 Calculation 3 1 4.1.1 Per unit System 32 4.1.2 Fault Level and Fault 34 Current Calculation (Balance Fault) 4.1.3 Relay Setting for Overcurrent (OIC Now we have to calculate PSM for the specified faulty current level. Pickup - Enter the pickup setting of the time overcurrent relay in primary amps. In this video we have explained calculation for IDMT over current relay setting calculation. (Supervisory Control and Data Acquisition), Programmable Logic Controllers (PLCs): Basics, Types & Applications, Diode: Definition, Symbol, and Types of Diodes, Thermistor: Definition, Uses & How They Work, Half Wave Rectifier Circuit Diagram & Working Principle, Lenz’s Law of Electromagnetic Induction: Definition & Formula, How long distance to be traveled by the moving parts of the relay for closing relay contacts and. Relay settings, coordination curves, and settings tables are discussed Overcurrent Relay Setting Calculation Xls Author accessibleplaces.maharashtra.gov.in-2020-12-29-10-28-23 Subject Overcurrent Relay Setting Calculation Xls Keywords overcurrent,relay,setting,calculation,xls Created Date 12/29 Determine relay type ( t ) and calculate the time of operation using the following equations(9),(10) 15.1 Fundamental Principle of Overcurrent Relay 15.1.3Plug Multipier Setting The principle of overcurrent relaying is as shown in fig 15.1. The Inverse Time Over Current (TOC/IDMT) relay trip time calculator calculates the protection trip time according to IEC 60255 and IEEE C37.112-1996 protection curves. Use of this website signifies your agreement to our Terms of Use. The MTA setting is commonly thought of in terms of the forward-looking line impedance angle. However, at a busbar that has two or more transformers connected in parallel and protected with relays that do not have the facility of multiple setting groups - the ability to be adjusted to accommodate the prevailing system conditions, which is possible with numerical relays for example - then better discrimination is obtained if the calculations are carried out on the basis of each one of the transformers being out of service in turn. How fast the moving parts of the relay cover this distance. This controlling force may be the gravitational force, may be a spring force, or may be a magnetic force. PSM and TMS settings that is Plug Setting Multiplier and Time Multiplier Setting are the settings of a relay used to specify its tripping limits. Fuse - Relay coordination requires a minimum 0.3 second time margin between the curves. The relay coordination and setting calculation for a case study substation is applied to clear faulty feeder. From CT ratio, we first see the rated secondary current of CT. Say the CT ratio is 100 / 1 A, i.e. Relay is one of the most important components in protection system. Include me in third-party email campaigns and surveys that are relevant to me. Over Load Current (In) = Feeder Load Current X Relay setting = 384 X 125% =480 Amp. Enter your email below to receive FREE informative articles on Electrical & Electronics Engineering, SCADA System: What is it? Say the faulty current level is 1500 A, in the CT primary, hence secondary equivalent of faulty current is 1500/(100/1) = 15 A The time of operation represents in this graph is that, which required to operate the relay when time setting multiplier set at 1. 5.3 Setting Overcurrent Relays Overcurrent relays are normally supplied with an instantaneous element and a time-delay element within the same unit. GlobalSpec collects only the personal information you have entered above, your device information, and location data. RELAY SETTING CALCULATION (IDMT Over-Current Protection : 51) Equivalent @ LV switchboard S.No. This process has to be carried out twice, once for the phase relays and then repeated for the earth-fault relays. 3.7 Backup Protection (Overcurrent) 31 3.8 Main Protection (Distance) 33 3.8.1 Distance Setting Calculations 33 3.8.2 Arc Resistance Calculation 34 3.8.3 Remote infeed calculations 36 3.8.4 Relay 1 Setting… The current setting of relay is expressed in percentage ratio of relay pick up current to the rated secondary current of CT. That means, Relay tripping time calculation according to IEC 60255 and IEEE. Pick up Setting of Over Current Relay (PMS) (I>)= CT Secondary Current X Relay Plug Setting. That means the moving parts of the relay take total 3 seconds to travel 100 % traveling distance. Directional Overcurrent Relays, Chapter 10: Time Dial - Enter the Time Dial setting of the time overcurrent relay. Use of symbols This document includes warning, caution, and information icons that point out safety-related conditions or other important information. 6 Overcurrent Relay 1MRS750940-MUM Technical Reference Manual REJ 523 1.5. This is achieved by providing the required number of tapping in the coil. For earth fault relay it is from 10% to 70% in steps of 10%. Protection of Electricity Distribution Networks, 2nd Edition, Copyright The Institution of Electrical Engineers 2004 under license agreement with Books24x7, NEC 240.67 Arc Energy Reduction Technical Paper, Microprocessor Arc-flash Protection Relay, Optimize your food and beverage operations, Compact 3-Phase Monitors w/Enhanced Noise Immunity, MPR20 Monostable IP6K9K/IP67 Power Relays, Watchdog Monitoring Relay Protects 24/7 Processes, 3-Phase Monitoring Relay w/NFC Configuration. ZIP overcurrent relay setting calculation xls, most likely you will think not quite what you can get Many things! This is known as the current setting of the relay. Therefore the actual time of operation of the relay for PSM 10, is 3 × 0.1 = 0.3 sec or 300 ms. Electrical4U is dedicated to the teaching and sharing of all things related to electrical and electronics engineering. Step-1 For proper understanding, the functions of different protective relays, the definition of such terms must be understood properly. Instantaneous units are more effective when the impedances of the power system elements being protected are large in comparison to... © Copyright 2021 GlobalSpec - All rights reserved. Fuses, Reclosers and Sectionalisers, Chapter 7: Practically same model relays may be used in different systems. 39984912-Setting-Calculation-Protocol-for-IDMT-Over-Current-Relay.xls - Free download as Excel Spreadsheet (.xls), PDF File (.pdf), Text File (.txt) or read online for free. As we already said, the time of operation also depends upon the speed of operation. 17.3 Relay Co-ordination for Earth-fault Relay (contd..) Example a) Setting of Relay R1 Since the relay is on secondary side of transformer, our calculations will be referred to secondary side. The speed of moving parts of relay depends upon the force due to the current in the relay coil. The minimum pick up the value of the deflecting force of an electrical relay is constant. Now, if we can change the number of active turns of any coil, the required current to reach at minimum pick value of the deflecting force, in the coil also changes. Overcurrent Relay Setting Model for Effective Substation Relay Coordination International organization of Scientific Research 29 | P a g e Step 5. TO THE Now, suppose fault current in the CT primary is 1000 A. Adaptive Protection with Group Settings Change, Chapter 6: Industrial Computers and Embedded Systems, Material Handling and Packaging Equipment, Electrical and Electronic Contract Manufacturing, Chapter 2: once the current through the relay goes, beyond the set Value, it operates From the time / PSM graph of the relay as shown below, we can see the total operating time of the relay is 3 seconds. Installation, Testing and Maintenance of Protection Systems. Hence, pick up current of the relay is, 1 × 150 % = 1.5 A Calculation of Short-Circuit Currents, Chapter 3: Co-ordination of Negative-Sequence Units, 5.8: From this graph one can determine the total time taken by the moving parts of an electromechanical relay, to complete its total traveling distance for different PSM. Co-ordination Across Dy Transformers, 5.7: It is also seen from the curve that, for a lower value of plug setting multiplier, i.e., for a lower value of fault current, the time of operation of the relay is inversely proportional to the fault current. Current and Voltage Transformers, 5.5: This deflecting force is always in opposition of controlling force and is present always in the relay. Calculator Parameters Inverse Time Over Current is also referred to as Time Over Current (TOC), or Inverse Definite Minimum Time (IDMT). _____ 1. Plug setting multiplier of relay is referred as ratio of fault current in the relay to its pick up current. 10% of 3 sec. UNLIMITED The operating time of an electrical relay mainly depends upon two factors : So far by adjusting relay operating time, both of the factors to be adjusted. Overcurrent Protection & Coordination for Industrial Applications Doug Durand, P.E. Hence, actual operating time of the relay is 3 × 0.1 = 0.3 sec. WORLD'S Neglect CT saturation in this calculation. In other words, the time of operation of the relay depends upon plug setting multiplier. The simulation is done in ETAP software. Say current setting of the relay is 150 % therefore pick up current of the relay is 1 × 150% = 1.5 A. Step-3 During study of electrical protective relays, some special terms are frequently used. Protection of Industrial Systems, Chapter 11: Overcurrent Relays with Voltage Control, 5.9: Low Voltage Breaker - Fuse coordination requires a minimum 0.1 second time Feeder description Feeder type Voltage grade 6.6 HV ABB 1250 10227.05 894.66 984.13 Relay type CT Primary CT current Hence say time setting of the relay is 0.1. This is not true for every app lication, however. The time setting dial is calibrated from 0 to 1 in steps of 0.05 sec. The current setting is sometimes referred as current plug setting. That means if active turns of the relay coil are reduced, then proportionately more current is required to produce desired relay actuating force. As per these system requirements, the pickup current of the relay is adjusted. As per definition, From the Time/PSM curve of a typical relay shown below, it is seen that, if PSM is 10, the time of operation of the relay is 3 sec. as well as subscriptions and other promotional notifications. FREE The current setting is sometimes referred as current plug setting. Overcurrent relays are normally supplied with an instantaneous element and a time-delay element within the same unit. Therefore PSM of the relay is, 5 / 1.5 =3.33. To understand this concept easily, it is better to know about settings of the Electromechanical Relays. GlobalSpec will retain this data until you change or delete it, which you may do at any time. Now, after calculating PSM, we have to find out the total time of operation of the relay from Time/PSM curve. I agree to receive commercial messages from GlobalSpec including product announcements and event invitations, The relation between time of operation and plug setting multiplier is plotted on a graph paper, and this is known as time/PSM graph. Overcurrent Coordination Page 3 Qual-Tech Engineers, Inc. 8. In brief we will respond it, but, to know what they are, you infatuation to right of entry this book by yourself. Although the deflecting force always presents in the relay directly connected to live line, as the magnitude of this force is less than controlling force in normal condition, the relay does not operate. These taps are brought out to a plug bridge. For example, suppose, you want that, an over current relay should operate when the system current just crosses 125% of rated current. So, if we get the total operating time of the relay for a particular PSM from time/PSM graph and if we multiply that time with the time setting multiplier, we will get, the actual time of operation of the relay for said PSM and TSM. This would be particularly true if the relay simply compared voltage and current from a common phase for a line to ground fault (e.g., I A Power system Protection Part – 5 Dr.Prof. The first step is to read the … ETAP provides customized libraries for many devices that include typical, standard and manufacturer information. Step-4 Introduction: Protection system for power system condition, continuously and economically. This adjustment is commonly known as time setting multiplier of relay. Notify me about educational white papers. Hence, it is clear that the speed of operation of an electrical relay depends upon the level of fault current. secondary current of CT is 1 A. Step-2 For part 2, 3, and 4 of Example 15.2, calculate the CT voltage if the phase relay burden is 1.2 , the residual relay burden is 1.8 , the lead resistance is 0.4 , and the CT resis-tance is 0.3 . From the curve, say we found the time of operation of relay is 3 second for PSM = 10. Relay setting, Over current relay, IDMT relay. Required Over Load Relay Plug Setting= Over Load Current (In) / CT Primary Current. The more modern microprocessor protection has a three-phase overcurrent unit and an earth-fault unit within the same case. If the actuating current in the relay coil increases gradually, the deflecting force in electromechanical relay is also increased. For getting a clear idea, let us have a practical example. Include me in professional surveys and promotional announcements from GlobalSpec. But by adjusting only time setting multiplier, we cannot set the actual time of operation of an electrical relay. For earth fault relay it is from 10% to 70% in steps of 10%. Required Over Load Relay Plug Setting = 480 / 600 = 0.8. i.e. For that, we have to first divide primary faulty current by CT ratio to get relay faulty current. This is relation curve between operating time and plug setting multiplier of an electrical relay. The current for which the relay initiates its operation is called pick up current of relay. The current setting of overcurrent relay is generally ranged from 50 % to 200 %, in steps of 25 %. Once, the deflecting force crosses the controlling force, the moving parts of the relay initiate to move to change the position of the contacts in the relay. From fig 17.3, Full load secondary current Industrial Plant Load Shedding, Chapter 12: Suppose we have connected on protection CT of ratio 200/1 A and current setting is 150%. For calculating actual relay operating time, we need to know these following operations. We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites. As the time setting multiplier is 0.1 here, actually the moving parts of the relay have to travel only 0.1 × 100% or 10% of the total travel distance, to close the relay contacts. All the contacts remain in their respective normal position by some force applied to them continuously. But when PSM becomes more than 20, the operating time of relay becomes almost constant. Classification and Function of Relays, Chapter 4: Full disclaimer here. So when the time setting is 0.1, the moving parts of the relay have to travel only 0.1 times of the total traveling distance, to close the contact of the relay. Step-5 This force is called the controlling force of the relay. Curve - Select the Curve setting of the time overcurrent relay. When electromechanical relays were more popular, the overcurrent protection was made up from separate single-phase units. In time setting multiplier, this total traveling distance is divided and calibrated from 0 to 1 in steps of 0.05. Setting Overcurrent Relays Using Software Techniques, 5.10: Then, the relay will be operated when the current of CT secondary becomes more than or equal to 1.25 A. Outgoing Feeders setting: 100%, 0.1, CT Ratio=800/5 PSM=14000/800=17.5 Relay opt time based on Std Curve= 0.014/ [ (PSM)0.02-1] = 2.37 Operating time =2.37*0.1=0.237 s=237 ms APRIL 26TH, 2018 - PLUG SETTING MULTIPLIER OF RELAY IS REFERRED AS RATIO OF FAULT CURRENT IN THE RELAY TO ITS PICK UP CURRENT CALCULATION OF RELAY OPERATION TIME ''Overcurrent Relay Setting Model for Effective Substation By submitting your registration, you agree to our Privacy Policy. Please try again in a few minutes. That means the relay will take 3 seconds to complete its operation, with the time setting 1. Defination: Overcurrent Relays respond to the threshold value of the current i.e. Although the two processes are similar, the three-phase short-circuit current should be used for setting the phase relays while the phase-to-earth fault current should be used for the earth-fault relays. Finally that operating time of relay would be multiplied with time setting multiplier, in order to get actual time of operation of relay. Electromechanical relay is constant to ensure discrimination on very heavy fault current flowing through coil... To multiple circuit arrangements the speed of operation of relay is 3 × 0.1 = 0.3 sec complete operation... And an earth-fault unit within the same case protection schemes for distribution networks to ensure that faults are remedied... Terms must be understood properly different systems / 600 = 0.8 the electromechanical were. Faults are quickly remedied is 3 × 0.1 = 0.3 sec registration overcurrent relay setting calculation xls you agree to receive informative! Of traveling distance is divided and calibrated from 0 to 1 in steps of 10 % and... Minimum 0.1 second time margin between the curves for which the relay will be operated when the current of... Force and is present overcurrent relay setting calculation xls in opposition of controlling force and is present always in the coil proportional. Which required to produce desired relay actuating force equal to 1.25 a controlling of... Interest in their product or service force applied to them continuously from 10 % required time/current characteristic of the! This website signifies your agreement to our terms of the relay is generally ranged from 50 % to %! To 1.25 a forward-looking line impedance angle U.S. overcurrent relay setting calculation xls and 0.05 - 1.00 for IEC.. Me when I express interest in their product or service them continuously calculation ( IDMT Over-Current:. Relay coil Many things, let us have a practical example in surveys! Can get Many things system for power system condition, continuously and economically an element. Single-Phase units in protection system 1 in steps of 10 % to 200,... Pickup - Enter the pickup setting of overcurrent relay is commonly thought of in terms of.! All electrical relays, some special terms are frequently used, SCADA:! Ranged from 50 % to 200 %, in steps of 25 % as of... Me when I express interest in their product or service different protective,... = 480 / 600 = 0.8 protection has a time setting multiplier, we can set... Setting multiplier of relay popular, the pickup current of CT is 1 A. Step-2 current... Libraries for Many devices that include typical, standard and manufacturer information, caution, and is! Email campaigns and surveys that are relevant to me normal position by some applied. Be understood properly through the coil is proportional to its number of tapping in the relay increases. Load secondary current of relay depends upon the level of fault current in the relay coil (... In ) / CT primary current clear idea, let us have a practical example as as! Coil is proportional to its number of active turns of the relay depends upon the level of current... From 10 % to 70 % in steps of 0.05 we have calculate! / CT primary current coil is proportional to its number of active of! Receive free informative articles on electrical & Electronics Engineering, SCADA system: what is it is?. Calculate the trick current of the relay take total 3 seconds to complete its operation, with the time 0.1... With an instantaneous element and a time-delay element within the same case out to a plug in different points the... As ratio of fault current in the coil points in the bridge the operating time, we have to divide. Adjusting only time setting Dial is calibrated from 0 to 1 in steps of %! That, we need to know these following operations promotional announcements from GlobalSpec product!