After calculating the Fault mVa, we have to calculate the Fault current. He is Technical Blogger and Familiar with English, Hindi, Gujarati, French languages. He has published numbers of Technical Articles in “Electrical Mirror”, “Electrical India”, “Lighting India”,”Smart Energy”, “Industrial Electrix”(Australian Power Publications) Magazines. have a good day. 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. 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 ™: NGR Monitoring . 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. It is determines or sets the level of fault current at which the short-time trip delay countdown is actuated. 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Ground fault protection systems overcur protection for phase and transformer protection bined directional over cur relay 67 over cur earth fault relays 50 51. for Current Density of Bus Bar Material=1.6 ? Distance protection calculation formulas and procedures 1. Fault Current = Fault mVA / Sq.root 3 * Rated voltage. 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. 7) Plug Setting Multiplier (PSM): It is the Fault current seen by the relay in the Multiples of Plug Setting. OHIO. GROUND FAULT. Pick-up Setting 51PP (for phase fault element) 51GP (for earth fault element) Time Multiplier Setting. What is the ref. Ground-Fault Protection – System grounding review – Ground-fault detection – Harmonic currents – Relay coordination ! ( Log Out /  9 Ground fault Pick Up Amps setting If the ground fault exceeds the set level, “Pick Up Amps”, the GF time delay will begin. PSM= If sec / PS = 20/ 0.9 = 22.22. 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. For coordination of other MCCB we need I2t ON with 0.2 Sec delay. 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). Jignesh Parmar has completed M.Tech (Power System Control), B.E(Electrical). Type CDG 11 Overcurrent And Earthfault Relay. Again, it should not be encroached by load. The ground fault protection scheme developed involves an overvoltage relay, connected across broken delta-connected VTs, that monitors zero sequence voltage. It is determines the level of fault current at which the ground fault trip delay countdown is actuated. Change ), You are commenting using your Google account. to aid in setting the relay elements correctly. He is member of Institution of Engineers (MIE) and CEng,India. The ground fault must be present for the full length of the time delay. (Since kva= sq.root 3 Rated line voltage * Rated line current) Hence we get the value of fault current. Transformer Vector Group and CT to Relay Connection. Enter your email address to follow this blog and receive notifications of new posts by email. For earth fault relay it is from 10% to 70% in steps of 10%. Per common practice, the element provides independent reach settings for the and ground phase elements, TD21MP and TD21MG, respectively. 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… Example1: We have Sub feeder MCCB Size of 2000A, Short Circuit Current is 4000A. He is Freelancer Programmer of Advance Excel and design useful Excel base Electrical Programs as per IS, NEC, IEC,IEEE codes. ( Log Out /  Motor Protective Settings 101308 Levine Lectronics And. Maximum Load Current is 1000A .What is Over current (Long Time) and Short Circuit (Short Time) and Instantaneous setting of MCCB. This can be dangerous to nearby personnel and could result in equipment damage. 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. Protection relay codes 24 8. 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. It can be set to I2t On and I2t OFF settings. 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. He wants to Share his experience & Knowledge and help technical enthusiasts to find suitable solutions and updating themselves on various Engineering Topics. 7 Comments. 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. Dial Setting=( Short Circuit Current/ MCB Rating) =4000/2000=2, Short Circuit Setting Isd=2xIn=2×2000=4000A. How about for setting of Ig what should be the setting thanks.. 1. B/C AND I/ OF MCC: 15-30% OF BUSBAR RATING. June 1, 2017 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. This paper offers a selection and setting guide for ground fault detection on noncompensated overhead power lines. Other fault So I need to know: ground primary fault current is calculated as: (EQ 3) Increases in phase current (Iph) due to the fault are negligible, meaning that . The short time delay can be set to I2t On and I2t OFF settings (Inverse Time Delay). About Jignesh.Parmar (B.E,Mtech,MIE,FIE,CEng)Jignesh Parmar has completed M.Tech (Power System Control), B.E(Electrical). Module 4 Overcur Protection Lecture 17 Earth Fault. We will start the transformer differential protection calculation with … SEL-551C Feeder Over-Current and Earth Fault. In this video we have described the method of calculation of relay settings and relay co-ordination. Littelfuse ground-fault protection relays offer the needed protection against ground faults. What should be distance of 11kv line vertically and horizontally from home ( Log Out /  He is Presently associate with one of the leading business group as a Deputy Manager at Ahmedabad,India. Earth fault relay should not pick up for the unbalance current 20% of 437A = 87.47A. Short Time delay sets the amount of time the breaker will carry both a low level and high fault currents before tripping. 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. 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. The short-time pickup (Isd) sets current level (below instantaneous trip level) at which circuit breaker will trip after the preset time delay. 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. 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. A typical ground-fault relay has an adjustable ground fault current pick-up setting and time-delay pick-up setting. It is determines the level of fault current that will actuate a trip with no time delay. Sharing Abstracts,Notes on various Electrical Engineering Topics. Note: PSM is used for time Calculation only and not required to be entered in the Relay Setting. what data should i collect to coordinate a series of pad mounted switches along the same feeder? Third 11kv line can pass through colony or it should pass along the main road only. Earth Fault Relay Setting Calculation Pehawe De. He is Technical Blogger and Familiar with English, Hindi, Gujarati, French languages. Setting calculation is separated for overcurrent and eart fault relay with input parameters: Name of Feeder, Load Current: (IL) in Amps, Min Fault 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. 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. Sorry, your blog cannot share posts by email. Charging Current – Sympathetic tripping – Tripping Ratio ! Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. Is these lines should be insulated when passing through already constructed area ? It is determines the amount of time the breaker will carry a ground fault before tripping. 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. Post was not sent - check your email addresses! 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. Protective relay functions and data. 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 … Ground fault protection for a power system network provides in two ways. Hi Sir, how to size ground and neutral fault protection of the above example? Relay Setting Calculation [EPUB] Earth Fault Relay Setting Calculation Book [PDF] PSM and TMS Settings Calculation of a Relay Protection. 20 6.5 Measurement of the ground fault current and identification of the faulted phase 22 7. ( Log Out /  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. thanks. He is FIE ,MIE and CEng from Institution of Engineers,India. (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. He is Freelancer Programmer of Advance Excel and design useful Excel base Electrical Programs as per IS, NEC, IEC,IEEE codes. Change ), You are commenting using your Facebook account. However, in some cases, motors may be equipped with instantaneous ground trips set in the range of 1 to 5 amps, depending upon the current setting of the HRG system. If the k factor is not accurate, therefore, fault reach (distance) will be … Change ), You are commenting using your Twitter account. Application Example on Transformer Differential Protection Calculation 25/33MVA 69/23kV Delta-Wye Transformer on SEL-387A Relay Figure 1. Relay Pickup current (Primary) = Plug Position (PSM) * … ARCING FAULT CURRENT AND THE CRITERIA FOR SETTING GROUND. No trip for a current below 80% of the instantaneous setting, Trip for a current equal to 120% of the instantaneous setting. Neutral-Grounding Resistor (NGR) Selection ! 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. 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. Figure 1 fault trip delay countdown is actuated fill in your details below or click an icon to in. An infringement of the above example detection – Harmonic currents – relay coordination,. 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