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. 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. Overcurrent Coordination Page 3 Qual-Tech Engineers, Inc. 8. Pickup - Enter the pickup setting of the time overcurrent relay in primary amps. But when PSM becomes more than 20, the operating time of relay becomes almost constant. 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. An error occurred while processing the form. Fuse - Relay coordination requires a minimum 0.3 second time margin between the curves. In time setting multiplier, this total traveling distance is divided and calibrated from 0 to 1 in steps of 0.05. From the time / PSM graph of the relay as shown below, we can see the total operating time of the relay is 3 seconds. 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. ZIP overcurrent relay setting calculation xls, most likely you will think not quite what you can get Many things! 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 Plug setting multiplier of relay is referred as ratio of fault current in the relay to its pick up current. Again the deflecting force of the coil is proportional to its number of turns and the current flowing through the coil. 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 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 This is relation curve between operating time and plug setting multiplier of an electrical relay. Co-ordination of Negative-Sequence Units, 5.8: Suppose we have connected on protection CT of ratio 200/1 A and current setting is 150%. 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. 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. That means the relay will take 3 seconds to complete its operation, with the time setting 1. 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. FREE The time setting dial is calibrated from 0 to 1 in steps of 0.05 sec. 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. This reference guide uses detailed examples and exercises to explain the co-ordination and inception of protection schemes. By submitting your registration, you agree to our Privacy Policy. 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. When electromechanical relays were more popular, the overcurrent protection was made up from separate single-phase units. From the curve, say we found the time of operation of relay is 3 second for PSM = 10. 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. The minimum pick up the value of the deflecting force of an electrical relay is constant. For calculating actual relay operating time, we need to know these following operations. 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. RELAY SETTING CALCULATION (IDMT Over-Current Protection : 51) Equivalent @ LV switchboard S.No. In brief we will respond it, but, to know what they are, you infatuation to right of entry this book by yourself. Required Over Load Relay Plug Setting= Over Load Current (In) / CT Primary Current. 5.3 Setting Overcurrent Relays Overcurrent relays are normally supplied with an instantaneous element and a time-delay element within the same unit. once the current through the relay goes, beyond the set Value, it operates Low Voltage Breaker - Fuse coordination requires a minimum 0.1 second time But by adjusting only time setting multiplier, we cannot set the actual time of operation of an electrical relay. From fig 17.3, Full load secondary current 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 10% of 3 sec. Therefore PSM of the relay is, 5 / 1.5 =3.33. Relay is one of the most important components in protection system. Defination: Overcurrent Relays respond to the threshold value of the current i.e. WORLD'S Full disclaimer here. Relay setting, Over current relay, IDMT relay. For proper understanding, the functions of different protective relays, the definition of such terms must be understood properly. Adaptive Protection with Group Settings Change, Chapter 6: The current for which the relay initiates its operation is called pick up current of relay. The simulation is done in ETAP software. All the contacts remain in their respective normal position by some force applied to them continuously. The time of operation represents in this graph is that, which required to operate the relay when time setting multiplier set at 1. 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. Finally that operating time of relay would be multiplied with time setting multiplier, in order to get actual time of operation of relay. 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 This is known as the current setting of the relay. i.e. Hence say time setting of the relay is 0.1. 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, During study of electrical protective relays, some special terms are frequently used. The current setting is sometimes referred as current plug setting. 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. 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… 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. Notify me about educational white papers. 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 . Industrial Computers and Embedded Systems, Material Handling and Packaging Equipment, Electrical and Electronic Contract Manufacturing, Chapter 2: Calculator Parameters Inverse Time Over Current is also referred to as Time Over Current (TOC), or Inverse Definite Minimum Time (IDMT). This adjustment is commonly known as time setting multiplier of relay. That means if active turns of the relay coil are reduced, then proportionately more current is required to produce desired relay actuating force. Mohammed Tawfeeq 011 Overcurrent Relay Setting 50 Elements: Pickup Setting 51 Elements Pickup setting Time delay setting definite time: time setting Calculation of Short-Circuit Currents, Chapter 3: Hence, pick up current of the relay is, 1 × 150 % = 1.5 A Classification and Function of Relays, Chapter 4: The same procedure can be applied to multiple circuit arrangements. The more modern microprocessor protection has a three-phase overcurrent unit and an earth-fault unit within the same case. These taps are brought out to a plug bridge. Say the faulty current level is 1500 A, in the CT primary, hence secondary equivalent of faulty current is 1500/(100/1) = 15 A Relay tripping time calculation according to IEC 60255 and IEEE. The speed of moving parts of relay depends upon the force due to the current in the relay coil. 6 Overcurrent Relay 1MRS750940-MUM Technical Reference Manual REJ 523 1.5. 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