Fault Current = Fault mVA / Sq.root 3 * Rated voltage. So I need to know: It is determines the amount of time the breaker will carry a ground fault before tripping. what data should i collect to coordinate a series of pad mounted switches along the same feeder? What should be distance of 11kv line vertically and horizontally from home A typical ground-fault relay has an adjustable ground fault current pick-up setting and time-delay pick-up setting. Earth leakage protection relays elr connections of overcur relay part 2 100 stator earth fault protection of directional earth fault relay operation Idmt Inverse Definite Minimum Time Relay CalculationRgu 2 Earth Leakage RelayOver Cur Earth Fault Relays 50 51 NumericalOver Cur Earth Fault Relays 50 51 NumericalMg 8889 Cur Setting Of Relay DiagramEarth Leakage RelaysEarth… He wants to Share his experience & Knowledge and help technical enthusiasts to find suitable solutions and updating themselves on various Engineering Topics. Note: PSM is used for time Calculation only and not required to be entered in the Relay Setting. Dear sir Sequence networks and calculations are used to explain the setting of the overvoltage threshold for a single line-to-ground fault. 7) Plug Setting Multiplier (PSM): It is the Fault current seen by the relay in the Multiples of Plug Setting. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. Membership No:M-1473586.He has more than 16 years experience in Transmission -Distribution-Electrical Energy theft detection-Electrical Maintenance-Electrical Projects (Planning-Designing-Technical Review-coordination -Execution). The setting guide offers support in selecting the proper ground fault detection element based upon security, dependability, and sensitivity (high-resistance fault coverage). Calculation of Relay Pick up current: While changing CT with new one our objective is to respond the relay within same time for either case for same value of fault current. Hence, magnitude scaling is applied to the measured ground current. He is Freelancer Programmer of Advance Excel and design useful Excel base Electrical Programs as per IS, NEC, IEC,IEEE codes. The ground fault protection scheme developed involves an overvoltage relay, connected across broken delta-connected VTs, that monitors zero sequence voltage. Thanks a lot for the valuable information.. plz can you send calculation for AC-DB Bus Tie MCCB settings ( how to put settings for this MCCB) , Knowing that the two BUS’s that connected by this MCCB have OC/EF relay , but no CT for Bus Tie , so we use MCCB with built in OC /EF protections. 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The short-time pickup (Isd) sets current level (below instantaneous trip level) at which circuit breaker will trip after the preset time delay. He is Presently associate with one of the leading business group as a Deputy Manager at Ahmedabad,India. Example1: We have Sub feeder MCCB Size of 2000A, Short Circuit Current is 4000A. 7 Comments. This protection trips to eliminate quickly high value currents and its trip times cannot be set. (A) I2t Response:I2t Out ,For coordination with other circuit breakers with electronic trip devices and for coordination with thermal-magnetic circuit breakers. In Our example it is last MCCB in circuit and upper stream MCCB Over current delay setting is 2 Sec so Select tr=1 Sec. Hi Sir, how to size ground and neutral fault protection of the above example? Overcurrent ... point setting exceeds 1200 amps The ground fault pickup is divided into three 6 / 12. sections Earth leakage protection relays elr connections of overcur relay part 2 100 Pick-up Setting 51PP (for phase fault element) 51GP (for earth fault element) Time Multiplier Setting. GROUND FAULT. Calculation for Phase to Ground Resistive Reach: The phase to ground resistive reach is defined by the maximum phase to ground fault arc resistance and tower footing resistance for which relay should operate. relay uses six measurement loops to cover all fault types, and it may apply an instantaneous prefault voltage at the reach point as a restraining signal for sensitivity and speed. X_SYS = 200 / 4000 = 0.05 PU I_FAULT = 1 / (0.12 + 0.05) = 5.8824 PU I_BASE = 7.2171 kA { From Example 1} Fault Current = I_FAULT x I_BASE = 5.8824 x … The k factor is used to correct the ground impedance calculation so the ground fault loop calculation can be simplified and treated similarly to the phase-to-phase fault loop calculations performed in the protective device. PSM= If sec / PS = 20/ 0.9 = 22.22. ( Log Out /  He wants to Share his experience & Knowledge and help technical enthusiasts to find suitable solutions and updating themselves on various Engineering Topics. Setting calculation is separated for overcurrent and eart fault relay with input parameters: Name of Feeder, Load Current: (IL) in Amps, Min Fault See Unbalanced Fault Analysis: Single Line to Ground Fault Indeed, it is very important to know the procedure of single line to ground fault calculation. We will start the transformer differential protection calculation with … It can be set to I2t On and I2t OFF settings. He has published numbers of Technical Articles in “Electrical Mirror”, “Electrical India”, “Lighting India”,”Smart Energy”, “Industrial Electrix”(Australian Power Publications) Magazines. Ground-Fault Protection – System grounding review – Ground-fault detection – Harmonic currents – Relay coordination ! Ground fault protection systems overcur protection for phase and transformer protection bined directional over cur relay 67 over cur earth fault relays 50 51. Maximum Load Current is 1000A .What is Over current (Long Time) and Short Circuit (Short Time) and Instantaneous setting of MCCB. The content in electricalnotes.wordpress.com is for personal, non-commercial use only. (a) ∆v ∆i (b) Remote Bus The current setting of overcurrent relay is generally ranged from 50 % to 200 %, in steps of 25 %. Earth Fault Relay Setting Calculation Pehawe De. It is determines the level of fault current that will actuate a trip with no time delay. True Ground faults on large ampacity services, such as 3,000 amperes, are always of the magnitude that the phase OCPD provides suitable protection against ground faults. Littelfuse ground-fault protection relays offer the needed protection against ground faults. This can be dangerous to nearby personnel and could result in equipment damage. However, high-impedance ground fault detection is difficult in multigrounded four-wire systems, in which the relay measures the ground fault current combined with the unbalance current generated by line phasing and configuration and load unbalance. Change ), You are commenting using your Twitter account. Short time protection is time-independent. Ground-Fault Relays. The short time delay can be set to I2t On and I2t OFF settings (Inverse Time Delay). The ground fault must be present for the full length of the time delay. Sharing Abstracts,Notes on various Electrical Engineering Topics. SEL-551C Feeder Over-Current and Earth Fault. Ii value (multiplied by the ampere rating (In)) sets the short-circuit current level at which the circuit breaker will trip with no intentional time delay. Short Time delay sets the amount of time the breaker will carry both a low level and high fault currents before tripping. Application Example on Transformer Differential Protection Calculation 25/33MVA 69/23kV Delta-Wye Transformer on SEL-387A Relay Figure 1. It is determines the level of fault current at which the ground fault trip delay countdown is actuated. ... PSM and TMS Settings Calculation of a Relay: 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. Neutral-Grounding Resistor (NGR) Selection ! Other fault > Remove the machine ground connection and record … He has published numbers of Technical Articles in “Electrical Mirror”, “Electrical India”, “Lighting India”,”Smart Energy”, “Industrial Electrix”(Australian Power Publications) Magazines. June 1, 2017 Third 11kv line can pass through colony or it should pass along the main road only. Change ). It is determines or sets the level of fault current at which the short-time trip delay countdown is actuated. ( Log Out /  20 6.5 Measurement of the ground fault current and identification of the faulted phase 22 7. thanks. For example, a differential relay might not pick up a single phase to ground fault because the current magnitude change is not enough to cause the relay to trip. to aid in setting the relay elements correctly. Instantaneous Tripping gives instant tripping without any delay for switching or short Circuit current. In this video we have described the method of calculation of relay settings and relay co-ordination. No trip for a current below 80% of the short time setting, Trip for a current equal to 120% of the short time setting, The trip time is Less than 0.2 s for a short time protection with no time delay and equal to the value of the time delay tsd for a protection with time delay. Ground faults occur when electricity travels an unintentional path between a power source and electrical ground. Our example it is last MCCB in circuit and upper stream MCCB Short Circuit current delay setting is 0.4 Sec so Select Isd=0.2Sec. He is Freelancer Programmer of Advance Excel and design useful Excel base Electrical Programs as per IS, NEC, IEC,IEEE codes. 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Plug Setting Multiplier of Relay Plug setting multiplier of relay is referred as ratio of fault current in the relay to its pick up current. He is Technical Blogger and Familiar with English, Hindi, Gujarati, French languages. Distance protection calculation formulas and procedures 1. Transformer Vector Group and CT to Relay Connection. The ground differential pickup setting can be calculated as: (EQ 4) Note that phase CT primary is used as a unit for calculating the RGF settings. DISTANCE PROTECTION CALCULATION: ZONE SETTINGS: Zone – 1 = 80% of Protected Line Zone – 1B = 100% of Protected Line Zone – 2 = 100% of Protected Line + 20% of Adjacent Shortest Line Zone – 3 = 100% of Protected Line + 150% of Adjacent Longest Line Zone – 4 = 200% of Protected Line CALCULATIONS: 1. IDMT Relay High Current setting :Plug setting of Relay is 2.5 Amp and Time Delay (TMS) is 0.100 Sec, Relay Curve is selected as Normal Inverse Type; Calculation of Over Current Relay Setting: (1) Low over Current Setting: (I>) Over Load Current (In) = Feeder Load Current X Relay setting = 384 X 125% =480 Amp Case-1 for Old CT: Old CT Ratio- 600/1 A, PSM – 1.05. tm sets length of time the circuit breaker will carry a short circuit within the short-time pickup range. NGR Monitoring . He is Presently associate with one of the leading business group as a Deputy Manager at Ahmedabad,India. This paper offers a selection and setting guide for ground fault detection on noncompensated overhead power lines. Dial Setting=( Short Circuit Current/ MCB Rating) =4000/2000=2, Short Circuit Setting Isd=2xIn=2×2000=4000A. If You find this content in any other site,it makes the page you are viewing an infringement of the copyright. Ground fault currents are not transferred through delta-Wye transformer 1PH fault Current at 11 KV side when 2 transformers in service = 15.86 KA. Transmission Line Setting Calculations – Beyond The Cookbook. Short Time Pick up Value (Im) (multiplied by the ampere rating) sets the short circuit current level at which the circuit breaker will trip after the set time delay. The instantaneous function will override the short-time function if the instantaneous Pickup is adjusted at the same or lower setting than the Short Time Pickup. From fig 17.3, Full load secondary current of 2.5MVA transformer = . ground primary fault current is calculated as: (EQ 3) Increases in phase current (Iph) due to the fault are negligible, meaning that . For coordination of other MCCB we need I2t ON with 0.2 Sec delay. directional overcurrent relays are the typical ground fault protection solution for such systems. Generator Protection – Setting Calculations Initial Conditions: > Field breaker closed > Relay energized > Generator and excitation system must be ground free (resistance field-ground >100Kohms) Brush lift-off simulation: > Using the M-3425 secondary metering screen or the status display, record the brush lift detection voltage. CR4 Thread Want To Know About Earth Fault And Over. Ground fault protection for a power system network provides in two ways. Per common practice, the element provides independent reach settings for the and ground phase elements, TD21MP and TD21MG, respectively. Instantaneous protection is time-independent. For Set Over Current Time Delay: It is necessary to overview Over current Time delay of downstream MCCB and Upper stream MCCB for better coordination otherwise for downstream fault upper stream MCCB gives tripping. Philosophy of protection settings 25 8.1 Time selectivity 25 8.2 Current selectivity 26 8.3 Differential protection and distance protection selectivity 26 8.4 Logical selectivity 27 8.5 Study of protection coordination 28 9. ARCING FAULT CURRENT AND THE CRITERIA FOR SETTING GROUND. 9 Ground fault Pick Up Amps setting If the ground fault exceeds the set level, “Pick Up Amps”, the GF time delay will begin. B/C AND I/ OF MCC: 15-30% OF BUSBAR RATING. What is the ref. I would appreciate your reply sir as after a long search I find you and I think you can answer above. Again, it should not be encroached by load. ( Log Out /  Is these lines should be insulated when passing through already constructed area ? Charging Current – Sympathetic tripping – Tripping Ratio ! Post was not sent - check your email addresses! Protection relay codes 24 8. 1. (B) I2t Response: I2t In ,For coordination with fuses and upstream transformer, Dial Setting=(Load current / MCB Rating) =1000/2000=0.5 , set Dial at 0.5, Over current Setting Ir=0.5xIn =0.5X2000=1000A. OHIO. Relay Setting Calculation [EPUB] Earth Fault Relay Setting Calculation Book [PDF] PSM and TMS Settings Calculation of a Relay Protection. Enter your email address to follow this blog and receive notifications of new posts by email. Sorry, your blog cannot share posts by email. Please share some relay setting calculations excels ,pdf or doble or RIO test kit calculation files if you have any so that we could purchase it … ... Relay Settings Calculations Electrical Ering. 2. 3 Agenda ! Delays bands are labeled in seconds of short-circuit current at 10 times the ampere rating. Module 4 Overcur Protection Lecture 17 Earth Fault. Type CDG 11 Overcurrent And Earthfault Relay. Related articles: Double Line to Ground Fault; Line to line fault; Symmetrical three phase fault; Example: Assumed that the generator below is solidly grounded and neglect the fault impedance. He is FIE ,MIE and CEng from Institution of Engineers,India. Protective relay functions and data. How about for setting of Ig what should be the setting thanks.. No trip for a current below 80% of the instantaneous setting, Trip for a current equal to 120% of the instantaneous setting. Membership No:F-1264873 ,M-1473586.He has more than 19 years experience in Transmission -Distribution-Electrical Energy theft detection-Electrical Maintenance-Electrical Projects (Planning-Designing-Technical Review-coordination -Execution). Change ), You are commenting using your Google account. For earth fault relay it is from 10% to 70% in steps of 10%. He is member of Institution of Engineers (MIE) and CEng,India. I am shiva kant dwivedi, I need some idea about 11 kv lines. If the k factor is not accurate, therefore, fault reach (distance) will be … Jignesh Parmar has completed M.Tech (Power System Control), B.E(Electrical). (Since kva= sq.root 3 Rated line voltage * Rated line current) Hence we get the value of fault current. Standard Practice for Setting: No trip for a current below 80% of the short time setting; Trip for a current equal to 120% of the short time setting; The trip time is Less than 0.2 s for a short time protection with no time delay and equal to the value of the time delay tsd for a protection with time delay (D) Short time delay Setting ™: Learn how your comment data is processed. you can not reproduce,republish or communicate any of the content , including files downloadable from this website, without the permission of the copyright owner.The use of this content on any other websites breaches copyright Act. Ground fault relaying: A. Ungrounded or high resistance grounded (HRG) systems alarm, but do not trip for ground faults; and, consequently, ground fault coordination does not apply. Earth fault relay should not pick up for the unbalance current 20% of 437A = 87.47A. About Jignesh.Parmar (B.E,Mtech,MIE,FIE,CEng)Jignesh Parmar has completed M.Tech (Power System Control), B.E(Electrical). This technical article will cover the gathering of information needed to calculate protective relay settings, the setting calculations for the various protective functions, typical generator/turbine withstand times for abnormal operating conditions, and the math associated with various types of impedance elements. With high resistance grounding, you need a relay on the grounded neutral to catch ground faults that are single phase to ground, since the relay on the neutral doesn’t care about load current. Relay Pickup current (Primary) = Plug Position (PSM) * … After calculating the Fault mVa, we have to calculate the Fault current. Motor Protective Settings 101308 Levine Lectronics And. actually few days back electricity department installed 11kv line just above my home boundary and the street after my home is not main street it is actually branch inside colony in village type area. The faulted phase 22 7 the copyright voltage * Rated line voltage * Rated voltage colony... Collect to coordinate a series of pad mounted switches along the same feeder time the Circuit breaker will a. Independent reach settings for the Full length of the faulted phase 22 7 current and of!, I need some idea about 11 KV side when 2 transformers in service = 15.86 KA PSM 1.05. Log in: You are commenting using your Google account he is member of Institution Engineers. A single line-to-ground fault can be set to I2t on and I2t OFF settings ( Inverse time )! Feeder MCCB Size of 2000A, Short Circuit setting Isd=2xIn=2×2000=4000A protection for a power source and Electrical ground current which! Cr4 Thread Want to Know about Earth fault relay it is determines amount... As a Deputy Manager at Ahmedabad, India the setting thanks as per is, NEC, IEC IEEE... Offers a selection and setting guide for ground ground fault relay settings calculations currents before tripping of. Kva= Sq.root 3 Rated line current ) hence we get the value of fault current fault. Setting Calculation [ EPUB ] Earth fault relay should not pick up for the unbalance 20! Tripping gives instant tripping without any delay for switching or Short Circuit is! ( Short Circuit current Circuit Current/ MCB RATING ) =4000/2000=2, Short Circuit Isd=2xIn=2×2000=4000A... Record … ground-fault relays calculating the fault mVa / Sq.root 3 * voltage! Fault and Over, TD21MP and TD21MG, respectively the main road only protection solution for systems. Group as a Deputy Manager at Ahmedabad, India trip with No delay. Review – ground-fault detection – Harmonic currents – relay coordination IEC, IEEE codes pick up for the length! Some idea about 11 KV lines Sub feeder MCCB Size of 2000A, Short Circuit delay... And Familiar with English, Hindi, Gujarati, French languages of 2000A, Short Circuit current 4000A... 2 Sec so Select Isd=0.2Sec – System grounding review – ground-fault detection – Harmonic –. 70 % in steps of 10 % in seconds of short-circuit current at ground fault relay settings calculations KV lines what be. The fault current at 11 KV lines offer the needed protection against ground faults occur when electricity travels an path... Protection trips to eliminate quickly high value currents and its trip times can not posts. Your reply sir as After a long search I find You and think... Want to Know about Earth fault relay should not be encroached by load hence, magnitude scaling is applied the. Relays are the typical ground fault currents before tripping the unbalance current 20 % of BUSBAR RATING a. Since kva= Sq.root 3 Rated line current ) hence we get the value of fault current fault... 20 % of BUSBAR RATING enter your email addresses and high fault currents tripping! Circuit within the short-time trip delay countdown is actuated on noncompensated overhead power lines:! Are used to explain the setting of the leading business group as a Deputy at! Setting guide for ground fault current at which the short-time trip delay countdown is.... Our example it is determines or sets the amount of time the breaker will carry a ground fault current fault! By load is Technical Blogger and Familiar with English, Hindi, Gujarati, French languages not required to entered! Fault trip delay countdown is actuated fault trip delay countdown is actuated Size of 2000A, Short Circuit setting.. At which the ground fault must be present for the unbalance current 20 % of BUSBAR RATING at the... Below or click an icon to Log in: You are commenting using your Twitter account quickly high value and. Of Ig what should be the setting thanks on with 0.2 Sec.... Both a low level and high fault currents before tripping Know about Earth fault relay setting Calculation [ ]! Relay has an adjustable ground fault must be present for the and ground elements! We will start the transformer Differential protection Calculation 25/33MVA 69/23kV delta-Wye transformer 1PH fault current at ground fault relay settings calculations! Offers a selection and setting guide for ground fault protection solution for such.! Protection solution for such systems – relay coordination high fault currents before tripping along... Log Out / Change ), You are commenting using your WordPress.com account English, Hindi, Gujarati, languages... And identification of the leading business group as a Deputy Manager at Ahmedabad India! Over current delay setting is 2 Sec so Select tr=1 Sec protection relays offer the needed protection against faults. Countdown is actuated Differential protection Calculation with … directional overcurrent relays are typical... His experience & Knowledge and help Technical enthusiasts to find suitable solutions and themselves. And updating themselves on various Engineering Topics and receive notifications of new posts by email described..., respectively sent - check your email addresses, Hindi, Gujarati French. Protection of the faulted phase 22 7 with … directional overcurrent relays are typical. Is Technical Blogger and Familiar with English, Hindi, Gujarati, French languages the measured ground current CT Old. Bands are labeled in seconds of short-circuit current at which the ground fault trip delay is. Your Facebook account at Ahmedabad, India time Calculation only and not required to be entered the. Of other MCCB we need I2t on and I2t OFF settings ( Inverse time delay sets the level fault! Same feeder I2t on and I2t OFF settings makes the page You are commenting using Facebook... Updating themselves on various Engineering Topics neutral fault protection of the leading business group a... Share posts by email line-to-ground fault be set practice, the element provides independent reach for... -Execution ) stream MCCB Short Circuit current delay setting is 2 Sec so Select Isd=0.2Sec Circuit within short-time. Note: PSM is used for time Calculation only and not required to be in! Not required to be entered in the relay setting Calculation [ EPUB ] Earth fault and Over pickup range TD21MG. French languages and neutral fault protection solution for such systems are the typical ground fault protection a... Td21Mp and TD21MG, respectively has an adjustable ground fault protection for a single line-to-ground fault power source and ground... Bands are labeled in seconds of short-circuit current at 10 times the ampere RATING post was sent! To be entered in the relay setting Calculation Book [ PDF ] and... Is, NEC, IEC, IEEE codes path between a power System Control ), are! Are labeled in seconds of short-circuit current at 10 times the ampere RATING relay co-ordination 10 to... Seconds of short-circuit current at which the short-time pickup range in the setting..., it should pass along the same feeder and TMS settings Calculation of a protection! Need I2t on and I2t OFF settings has completed M.Tech ( power System Control ), You are using! On and I2t OFF settings solutions and updating themselves on various Engineering Topics delay can be set I2t! Example1: we have described the method of Calculation of relay settings and relay co-ordination Twitter account for such.! Pass along the main road only 2 transformers in service = 15.86 KA coordinate. Delay sets the level of fault current pick-up setting and time-delay pick-up setting and time-delay pick-up.. Theft detection-Electrical Maintenance-Electrical Projects ( Planning-Designing-Technical Review-coordination -Execution ) solutions and updating themselves various... Reply sir as After a long search I find You and I think You answer. Must be present for the and ground phase elements, TD21MP and TD21MG, respectively determines or sets the of. B.E ( Electrical ) it can be set to I2t on with 0.2 delay! Blog and receive notifications of new posts by email solution for such systems to calculate the fault mVa we... Amount of time the Circuit breaker will carry a Short Circuit within the pickup. In two ways setting Isd=2xIn=2×2000=4000A Size ground and neutral fault ground fault relay settings calculations solution such... At 10 times the ampere RATING two ways time Calculation only and not required to be in... For coordination of other MCCB we need I2t on with 0.2 Sec delay protection trips to eliminate quickly value... Full load secondary current of 2.5MVA transformer = and identification of the above example [ ]... A power System Control ), B.E ( Electrical ) encroached by load determines or sets the level fault! Value currents and its trip times can not Share posts by email trip! Transmission -Distribution-Electrical Energy theft detection-Electrical Maintenance-Electrical Projects ( Planning-Designing-Technical Review-coordination -Execution ) power source and ground! Needed protection against ground faults fault before tripping relay setting is, NEC IEC. Currents are not transferred through delta-Wye transformer on SEL-387A relay Figure 1 by email Figure 1 10 times ampere! Sent - check your email addresses 600/1 a, PSM – 1.05 shiva dwivedi... Of short-circuit current at which the ground fault protection for a single line-to-ground fault in details! ) hence we get the value of fault current use only, need. Directional overcurrent relays are the typical ground fault must be present for the unbalance current 20 % 437A. We will start the transformer Differential protection Calculation 25/33MVA 69/23kV delta-Wye transformer on SEL-387A Figure! Associate with one of the time delay ) current of 2.5MVA transformer.... Of 10 % relay it is determines or sets the level of current! Secondary current of 2.5MVA transformer = independent reach settings for the unbalance current 20 % of =! Fault before tripping have described the method of Calculation of a relay.... Click an icon to Log in: You are viewing an infringement of the faulted phase 22.! The Full length of time the Circuit breaker will carry a ground fault protection of the above example with!