CT Calculator

March 24, 2018 | Author: Ashirvad Rath | Category: Relay, Electrical Impedance, Transformer, Electrical Resistance And Conductance, Manufactured Goods
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Calculation of CT ParameterDescription Parameter Remark From generator Data sheet From generator Data sheet (i) Generator parameter Rated Voltage(kV) Rated Current(Amp) Sync. Reactance Xd is 1/SCR Subtransient Reactance Xd"(Saturated) Transient Reactance Xd' (Saturated) Rated Voltage at -5% FL current at -5%of rated Voltage= 19 9116.3 200.0 12.0% 20.0% 18.05 9596.1 Voltage at + 5% FL current at +5% of rated Voltage= 19.95 8682.2 Choose CT ratio = 11000/1 105% of rated current at (-)5% of rated voltage 10075.94 Choose CT ratio = 11000/1A 11000 This gives an over load capability 1.21 % O/L Capability of Full Load Current 120.66 1) Calculation of CT parameter for generator differential protection (87G) Relay setting VR = If (RCT + 2RL + Rrelay) where , Where If = fault current on CT sec, RCT = CT secondary resistance, Rrelay = Relay resistance in ohms, RL = Resistance of cable in ohms, RL in  for 100m of 2.5mm2 0.887 (Considering 100 m of 2.5 sq.mm Cu cond. cable between busduct CT & GRP the resistance of 2.5 sq.mm Cu cond cable at 70 oC in  / km (from KEI catalogue) 8.87 Relay resitance/phase Assumed Rrelay from SEC 0.1 Fault contribution from Gen in MVA= Taking 30% - Ve tol on Xd” as per IEC-34 part –I 3571.43 Fault contribution from system in MVA considering 40KA system Impedence on 220KV Side. Source impedence in Percentage at 300 Base 2024.10 Taking higher of the above two values = 3571.43 1.97% Fault Current in KA Taking higher value of the fault contribution from i.e. fault contribution from system / fault contribution from gen 108.52 Secondary Fault Current 9.87 VR = 9.87 (RCT +2x0.887+0.1) E47*(RcT+2*E31+E35) Vk = 2 VR 2*9.87* (RCT +2x0.887+0.1) Expressing VK term of +40V 19.74Rct+36.99 Vk = 20RCT + 37 Im  15 mA at Vk/2 Page 1 of 20 CT with group-1/group-2 protection 11000/1A, CLPS, Vk  20RCT + 36V Im  15 mA at Vk/2 (ii) METERING CORE CT chosen 11000/1A, 30VA, CL 0.2 ISF  5 Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer 0.4 7 Total 10Nos Analogue meter connected & max 4 nos of transducer per CT 2 Max. Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden Lead Burden for lead length of 100M= I2x(Rct+2RL) Rct Assumed for CT Sec.1A is 15 ohm for 11000/1Amp Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 30 VA, CL-0.2 =Sqr(1)*(Rct+2Rl) =Rct+1.774 16.774 26.174 As meter used is Multifunction type, hence 30 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear. Calculation of CT parameter for (87- 0A) on 19 kV side Same as generator differential protection CT core 11000/1A, CL-PS, Vk ≥ 20Rct + 36V, Im ≤ 15mA at Vk/2 2 CT on 220 KV side of Generator Step up transformer Bay i) Core –1 (87- 0A) 512.40 GT HT side current (current on 400 kV side) = = 513 A RL = 8.87x0.27 (considering 270m)= 2.3949 Rrelay = 0.1 CT ratio chosen = 600/1A VK = 40xIx(RCT+2RL+Rrelay) Fault current on 400KV side taken as 40KA = 40x1 (RCT +2x2.3949+0.1) =40 RCT+195.592 = VK  40 RCT+200V CT ratio 600/1A CLPS , VK  40 RCT+200V Im  30 mA at VK/2 ii) Core –2 (50 LBB, 51GT) R relay= 0.1 (from relay catalogue of ABB) 600/1A Total Burden on CT = Lead Burden+ Relay Burden Lead Burden for lead length of 270M= I2x(Rct+2RL) Rct Assumed for CT Sec.1A is 6 ohm Total Burden on CT = Lead Burden+ Relay Burden R relay= 0.1 (from relay catalogue of ABB) =Sqr(1)*(Rct+2Rl) =Rct+4.79 10.79 10.89 Page 2 of 20 2 iv) 2 =Sqr(1)*(Rct+2Rl) =Rct+4. earth fault current I = F.79 10.27 = 2.9 ( -ve tol of 10%) 3457.5 Total 5Nos Analogue meter connected & max 4 nos of transducer per CT Max. VK  40 RCT + 200V.3949 VK = If (RCT + 2 Rlead + Rrelay) RCT value from CT manufacturer Bus bar protection is a numerical relay VK = 40x1 (RCT +4. Parameters same as core-4.79 17.69 20 VA arrived at considering all the meter connected Core –4 (87 B1/B2) Fault level of switchyard = 40 kA for 1 sec.5 mm2 Cu cond cable 270 m length (max) RL = 8.5% Choosing bushing CT of 600/1 on GT HV side & neutral side Page 3 of 20 . CL5P20 Cater the Load burden of Numerical Relay iii) Core –3 (metering) 600/1A Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer 0.50% Considering SPAE 10 relay with 200V mAburden =5.15 VA.2) = 40 RCT + 199.15 = 3607. VK  40 RCT + 150V Im  15 mA at VK/2 A GT Bushing CTs i) Core-1 Phase CT for REF protection (64 GT) % Impedence of GT is GT full load current on HV side = 512. max.6 Knee point voltage selected is 40 RCT + 200V CT ratio chosen 600/1A CLPS . Im  15 mA at VK/2 v) Core –5 Spare core .1A is 6 ohm for 600/1Amp Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 20 VA. Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden Lead Burden for lead length of 270M= I2x(Rct+2RL) Rct Assumed for CT Sec.40 14.79+0.4 4. CT ratio chosen 600/1A CT sec lead resistance with 2.4 VA Setting227 relay Considering the Source impedance based on 40kA.L current / % Z x 0. CL-0.87x0.70 as GT impedance Zt = 14. 0845 Fault contribution from generator is Base MVA/Fault MVA 4201.8 Zspu with 10% negative tolerance = Zgt with 10% negative tolerance 1.4836 8. CL-5P20 B =Sqr(1)*(Rct+2Rl) =Rct+2.4/1) VK ` = 6.120 Zg with 30% neg tolerance Zg (pu) = 0.01 ( RCT + 2 x 1.76 ∴ VR = If (RCT + 2RL + R relay) = 6.85% Zg (pu) with 355MVA base= 0.242 + 5.152 13.6836 As relay used is Numerical type.7= 10.05% 13.2 Typical Relay burden in ohm (from ABB catlogue) Total Burden on CT = Lead Burden+ Meter Burden Lead Burden for lead length of 140M= I2x(Rct+2RL) Rct Assumed for CT Sec.CT sec. thro'fault current = 3607. 140 m length VK read = atleast 2 VR VK = 2x(6.01 RCT + 47. UAT BUS DUCT MOUNTED CTS Formula used / reference / design assumption (87UAT) (HV side) i) Core –1 (50 UAT – HV side) For a fault at UAT HV terminals Fault contribution from generator Base-MVA Generator Xd” sat From Generator data sheet 355 0.38 2.5 mm2 Cu cond.01 RCT + 47.155X0. CL 5P20 P20 because Chracteristic will get smoothen after 20 times of rated current 0.15% 1.05 Page 4 of 20 .1A is 6 ohm for 600/1Amp Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA.2 Neutral CT-GT inverse time ground O/C relay (51NGT) CT chosen 600/1A 20 VA.084 0. equiv.38)V VK = 12.4836 8. hence 10 VA considered is more than Sufficient.5 RCT + 100V CT parameters chosen CT ratio 600/1A VK  13 RCT + 100 V Im < 30 mA at VK/2 ii) Same CT parameter is applicable for neutral REF CT Core .70 x1/600 5.68 Fault contribution from 400KV system in MVA 27712. e.49 = 2499.49 MVA Total fault MVA(Contribution from Generator & GT system) = 3252. CT ratio will be VK = 40xIx(RCT + 2RL + R relay) CT ratio choose CT = 800/1A = 40x1x(RCT +2x8. developed by the CT (200V) will be increased by that ratio.e – 5%. CL-5P20 (iii) 0. Im  15 mA at VK/2 UAT rating – 20 MVA Current on 20 kV side = 577.40 MVA Fault current 6701.1) VK >40RCT+92.91+2499.87x100/1000 Im  15mA AT VK/2 C UAT LV side CTs i) Core –1 (87.38 Ratio of fault current to CT ratio < 20 times However the ratio of rated burden of CT & the connected burden is about 10 times.49 = 5752.17 = 166. Therefore the voltage. 10VA 10181.1A is 7 ohm for 600/1Amp Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA.2175 9.04 ∴ CT chosen – 2000/1A This also cater the installed Capacity of UAT i.6 kV bus ( higher of the two buses U1A and U1B taken from UAT sizing calculation) 1614. Core – 3 (87 UAT-HT side) 800/1A . CL PS .87x0. hence 10 VA considered is more than Sufficient.1 =Sqr(1)*(Rct+2Rl) =Rct+2.3175 As relay used is Numerical type.0A) (UAT-LV) Total running load in KVA on the 6.35 607. CL 5P20 Typical Relay burden in ohm (from ABB catlogue) Total Burden on CT = Lead Burden+ Relay Burden Lead Burden for lead length of 125M= I2x(Rct+2RL) Rct Assumed for CT Sec.System contribution = Base MVA / (Zspu+Zgt) 2499.63 CT Chosen = 8500/1A Cl 5P20.96 Vdesin=BurdenxALF/CT Secondary Core – 2 (51 UAT – HV side) CT chosen – 800/1A 10VA.74 800/1A At the lowest tap i.125 +0.7 VK  40RCT+92.7V 2x8.06 KA 203. therefore the CT does not saturate and hence CT chosen is ok. (ii) 23. 20MVA Page 5 of 20 .6 kV bus ( higher of the two buses U1A and U1B taken from UAT sizing calculation) 18451 Total running load in Amp on the 6.2175 9. 87 x 0.774 VK = 40x1(RCT + 1. iii) Core –3 (51 UAT .LV side & 87-UAT 20/16 MVA . CLPS. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.887+0. L = 100 meters) 2. ISF  5 Typical Meter burden in ohm (from catalogue of Conzerv model) Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden Lead Burden for lead length of 50M= I2x(Rct+2RL) Rct Assumed for CT Sec.96 VK selected is  40RCT+80V CT chosen 2000/1A. 20/6. 10VA.5 mm2 cable / phase.21x(Rct+2x0. For neutral CT to be located in NGR.26 =10Rct+20V Im  15mA at Vk/2 Since the phase side CTs for REF protection will be same as that used for 87 UAT.661 = 1.887 Rct Assumed for CT Sec. Page 6 of 20 .LV) 2000/1A.987 0.887 12. same parameters as that of core-2 will be provided for neutral CT to be located in NGR or Neutral Bushings of transformer.5 .96 74.LV.2 2 =Sqr(1)*(Rct+2Rl) =Rct+0.1) = 40RCT+74. Earth Fault current to be restricted to 300Amp.087 As meter used is Multifunction type. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear. CL 0.1A is 6 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA.28 = 18.21 VK = 9.1) = 9. CL 5P20 R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden Lead Burden for lead length of 50M= I2x(Rct+2RL) 0.9 KV Rated Current of Unit Transformer at nominal Tap 1749.774 + 0. CL5P20 As relay used is numerical(SPAJ-140C) type. iv) Core –4 (Metering) 2000 / 1A .1 (1 run 2.1A is 12 ohm Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 20 VA.55 Fault Current limited by transformer impedance of 10% at -5% 18416.2 64-UAT .887 6. Vk  40RCT+80V Im  15 mA at Vk/2 ii) Core .1 =Sqr(1)*(Rct+2Rl) =Rct+0. CL5P20 v) 6.VK = 40 x I (RCT + 2RL + R relay) 2 RL = 2 x 8. 10VA .416 KA Fault Current reflected on CT Secondary 9.887 15.21 RCT + 17. 51 N – UAT. 300/1A.64 RST . From Above Full Load Current 0.2 (ST .6 kV bus ( higher of the two buses C1A and C1B taken from ST sizing calculation) 22292 Total running load in Amp on the 6.887 15. 11RCT+50V.5% at -15% 25728.887 15.987 Page 7 of 20 .04 Taking into consideration 25MVA(Rated Installed Capacity) Current is 2187Amp Typical Meter burden in ohm (from catalogue of Conzerv model) Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden Lead Burden for lead length of 50M= I2x(Rct+2RL) 0. CL 5P20 R relay in ohm (from relay catalogue of ABB model SPAJ) 2500/1A Total Burden on CT = Lead Burden+ Relay Burden Lead Burden for lead length of 50M= I2x(Rct+2RL) Rct Assumed for CT Sec.887 Rct Assumed for CT Sec.5 mm2 cable / phase. 220/6.1A is 15 ohm Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 2500 / 1A .087 As meter used is Multifunction type.87 x 0. CTR chosen .435 4.29 RCT + 46.29x(Rct+4. 20VA.67 = 11RCT+46.67 = 10.LV) 2500/1A.887 18.73 KA Fault Current reflected on CT Secondary 10.29 2 RL = 2 x 8.e. 15VA. ISF  5 ii) 15.6 kV bus ( higher of the two buses C1A and C1B taken from ST sizing calculation) ∴ CT chosen – 2500/1A 1950. hence 20 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.1A is 15 ohm Total Burden on CT = Lead Burden+ Relay Burden 20 VA.LV side) 25 MVA .435+0.67 V i.62 = 25.2500/1A. L = 250 meters) = 4.5 . CL 0.93 Fault Current limited by transformer impedance of 14. Core .435 Vk = 10.1) 46. CL 5P20 D ST LV side CTs i) Core –1 ( metering) Total running load in KVA on the 6. CL5P20 As relay used is numerical(SPAJ-140C) type.2 2 =Sqr(1)*(Rct+2Rl) =Rct+0. Im  15mA at Vk/2 iii) Core –3 (51 ST .9 KV Rated Current of Station Transformer at nominal Tap 2186.1 =Sqr(1)*(Rct+2Rl) =Rct+0. 20VA . hence 20 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.20 (1 run 2. 435 VK = 40x1(RCT + 4. L = 250 meters) 2.4 VK selected is  40RCT+200V CT chosen 2500/1A. Vk  40RCT+115V Im  15 mA at Vk/2 Page 8 of 20 .1) = 40RCT+181.iv) Core –4 (87.661 = 4.LV) ∴ CT chosen – 2500/1A From Above Full Load Current VK = 40 x I (RCT + 2RL + R relay) 2 RL = 2 x 8.ST. CLPS.435 + 0.87 x 0.5 mm2 cable / phase.15 (1 run 2. 6 kV System SNo.5 2 i.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 15 VA. CL-0.7096 Page 9 of 20 .7096 Rct Assumed for CT Sec. hence 15 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.6/0.7983 R relay = 0.7096 6. Condensate Extraction Pump-1A.7096 6.1A is 7 ohm for 750/1Amp 7.9096 As meter used is Multifunction type. CL5P20 7.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use 0.6 kV Unit switchgear (U1A & U1B) comprising of the following panels with ratings and accessories as indicated in single line diagram.1 Vk>= 40Rct+70V.6/0. 1B For Differential Protection Motor rated Current = 5400/Sqrt(3)/6. Boiler Feed Pump-1A.87X0.1A is 7 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA.1 Vk>= 40Rct+70V.8096 As relay used is numerical(SPAJ-140C) type.7096 7. Im<=30mA at Vk/2 ii. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.864V RL = 8. specification & data sheet. iii. 10.86 = 40*1*(Rct+2x0.7983+0.1) = 40Rct+67.1 =Sqr(1)*(Rct+2Rl) =Rct+0.7096 Lead Burden for lead length of 40M= I2x(Rct+2RL) Rct Assumed for CT Sec.2 1 2 Total Burden on CT = Lead Burden+ Meter Burden =Sqr(1)*(Rct+2Rl) =Rct+0. A Type of switchboard Feeder Rated Load current rating (kW) CT ratio Remark 6.21 RL = 8.87X0. 1100 150/1 113.1A is <=6 ohm Total Burden on CT = Lead Burden+ Relay Burden 0.09 (Considering 90m Length from Motor terminal to Relay)=0. Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden Lead Burden for lead length of 40M= I2x(Rct+2RL) Rct Assumed for CT Sec. 1B For Differential Protection Motor rated Current = 1100/Sqrt(3)/6. Motor Feeder 1 i.09 (Considering 90m Length from Motor terminal to Relay)=0. For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0.7983 R relay = 0.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) = 40*1*(Rct+2x0.7983+0.CT sizing for 6.1) = 40Rct+67.864V ii.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) 5400 600/1 524. 9096 ID-1A.1A is 6 ohm for 750/1Amp 6.66 V ii.1 Page 10 of 20 . For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use 0.7096 Rct Assumed for CT Sec. =Sqr(1)*(Rct+2Rl) =Rct+0.48 100/1 0.6/0. CL-0.7096 Rct Assumed for CT Sec.1A is 6 ohm for 750/1Amp 6.87X0.5 9.10 VA.996+0.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) 3 i. Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0. 1B For Differential Protection Motor rated Current = 1100/Sqrt(3)/6.996.7096 6. Also Rct is max typical value for 750Amp Primary 2240 300/1 222.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear. CL5P20 iii.1 Vk>= 40Rct+175V.67 = 40*1*(Rct+2x1.1) = 40Rct+163.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA. CL-0. R relay = 0. =Sqr(1)*(Rct+2Rl) =Rct+0.7096 6. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0.7096 Rct Assumed for CT Sec. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear. RL = 8. CL5P20 iii.9096 FD-1A. 1B For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden As meter used is Multifunction type. As relay used is numerical(SPAJ-140C) type. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.2 1 2 Total Burden on CT = Lead Burden+ Meter Burden Lead Burden for lead length of 40M= I2x(Rct+2RL) 4 i.225 (Considering 225m Length from Motor terminal to Relay)=1. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.5 9.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) As meter used is Multifunction type. As relay used is numerical(SPAJ-140C) type. Also Rct is max typical value for 750Amp Primary 800 87.1A is <=6 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA. ii.7096 5.6/0.1 Page 11 of 20 . Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0. 5.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) As meter used is Multifunction type.9096 PA-1A. 1F For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) As meter used is Multifunction type. =Sqr(1)*(Rct+2Rl) =Rct+0.5 8. CL-0.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.1 (Considering 100m Length from Motor terminal to Relay)=0.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) 5 i. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear. 1E.1A is 4 ohm for 100/1Amp 4. CL5P20 6. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0.7096 Rct Assumed for CT Sec. Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0. CL-0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) 6 i.1 Vk>= 40Rct+80V.7096 Rct Assumed for CT Sec.7096 Rct Assumed for CT Sec. 1600 200/1 164. RL = 8.1A is 5 ohm for 200/1Amp 5.9096 Coal Mill-1A.66 = 40*1*(Rct+2x0. CL5P20 iii.96V ii.87X0. 1B For Differential Protection Motor rated Current = 1100/Sqrt(3)/6.7096 Rct Assumed for CT Sec.7096 6.74 50/1 3C x 185 mm2 0. 1C. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.5 7. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0.8096 As relay used is numerical(SPAJ-140C) type. 1D.7096 As relay used is numerical(SPAJ-140C) type. =Sqr(1)*(Rct+2Rl) =Rct+0.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA.887 R relay = 0.887+0.1A is <=5 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA.1) = 40Rct+74. 1B. 400 43.1A is <=4 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.Total Burden on CT = Lead Burden+ Relay Burden ii.7096 1.9096 CWP-1A.548 R relay = 0.400 (Considering 400m Length from Motor terminal to Relay)=3.08 = 40*1*(Rct+2x3. 1400 200/1 144. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear. 1B For Differential Protection Motor rated Current = 1100/Sqrt(3)/6.87X0.9096 Main Incomer from Unit Transformer For O/C & E/F Protection As meter used is Multifunction type. Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0. CL-0.7096 Rct Assumed for CT Sec.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) 8 i.7096 Rct Assumed for CT Sec.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA.7096 Rct Assumed for CT Sec.1A is <=5 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0.8096 As relay used is numerical(SPAJ-140C) type.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) 7 i.7096 5. 3C x 185 mm2 =Sqr(1)*(Rct+2Rl) =Rct+0.5 4. CL5P20 1.7096 Rct Assumed for CT Sec.1A is 5 ohm for 200/1Amp 5.8096 As relay used is numerical(SPAJ-140C) type.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) As meter used is Multifunction type.1) = 40Rct+287.6/0.5 8. Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear. RL = 8. CL-0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.1A is <=1 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA. 5.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA.548+0. =Sqr(1)*(Rct+2Rl) =Rct+0.1 Vk>= 40Rct+290V.1A is 5 ohm for 50/1Amp 1. CL5P20 iii. 2000/1 Page 12 of 20 .84V ii. 8096 As relay used is numerical(SPAJ-140C) type.1A is 6 ohm for 2000/1Amp 6.1A is <=6 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.5 9. specification & data sheet.79 219.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.7096 Rct Assumed for CT Sec.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA.79 300/1 3C x 240 mm2 0.6 kV Unit switchgear (U2A & U2B) comprising of the following panels with ratings and accessories as indicated in single line diagram. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear. CL5P20 6. 10 Spare motor feeder on all the Unit-1 buses 5400 590.R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0. hence 15 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0. hence 15 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear. ii. hence 20 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear. 12.5 9 i. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden Lead Burden for lead length of 40M= I2x(Rct+2RL) 0.7096 Rct Assumed for CT Sec.9096 As meter used is Multifunction type. CL5P20 ii.1A is 12 ohm for 2000/1Amp Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 20 VA.79 300/1 300/1 2000/1 CT Details same as Unit service Trans.2 1 2 =Sqr(1)*(Rct+2Rl) =Rct+0.9096 As meter used is Multifunction type.7096 6.1A is <=12 ohm 12. CL-0. feeder CT Details same as I/C feeder from Unit Transformer B 6. Unit Service Transformer-1A & 1B For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 12.47 600/1 CT Details same as Feedpump Motor feeder 11 12 13 Spare transformer feeder on all Unit-1 buses ESP Service Transformer Feeder-1A & 1B feeder Tie to C1A & C1B 2500 2500 219.7096 Rct Assumed for CT Sec.7096 Rct Assumed for CT Sec. 2500 219. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0. Motor Feeder Page 13 of 20 .7096 15.7096 Total Burden on CT = Lead Burden+ Relay Burden 15 VA. CL-0.8096 As relay used is numerical(SPAJ-140C) type. 10.864V ii.1A is 7 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA. CT Details same as above Feedpump Motor feeder 7.864V ii.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 15 VA.87X0. Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0. hence 15 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.1) = 40Rct+67. 2B i.09 (Considering 90m Length from Motor terminal to Relay)=0.5 2 i.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0. RL = 8. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0.6/0. 1100 150/1 113.7983 R relay = 0.7983+0.7096 Rct Assumed for CT Sec.8096 As relay used is numerical(SPAJ-140C) type.7096 7.1A is 7 ohm for 750/1Amp 7.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.1 Boiler Feed Pump-2A.7096 As relay used is numerical(SPAJ-140C) type.21 RL = 8.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) 5400 600/1 524.7983+0. CL-0.87X0. CL5P20 6. CL5P20 iii. 2B For Differential Protection Motor rated Current = 1100/Sqrt(3)/6.7096 Page 14 of 20 . Condensate Extraction Pump-2A.7096 6. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.7096 Rct Assumed for CT Sec. Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0.7983 R relay = 0.1A is <=6 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA.2 1 2 =Sqr(1)*(Rct+2Rl) =Rct+0. For Differential Protection Motor rated Current = 5400/Sqrt(3)/6.1 Vk>= 40Rct+70V.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.1) = 40Rct+67.86 = 40*1*(Rct+2x0.6/0.09 (Considering 90m Length from Motor terminal to Relay)=0.7096 Rct Assumed for CT Sec. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden Lead Burden for lead length of 40M= I2x(Rct+2RL) 0.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) = 40*1*(Rct+2x0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.9096 As meter used is Multifunction type.1 Vk>= 40Rct+70V. iii. RL = 8. 6.995+0. 2B For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden Lead Burden for lead length of 40M= I2x(Rct+2RL) Rct Assumed for CT Sec.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA. Also Rct is max typical value for 750Amp Primary 2240 300/1 222.9096 ID-2A. CL-0.1A is 6 ohm for 750/1Amp 6. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.7096 As relay used is numerical(SPAJ-140C) type.48 100/1 3C x 185 mm2 0. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use 0.2 1 2 Page 15 of 20 . =Sqr(1)*(Rct+2Rl) =Rct+0. CL5P20 iii.7096 Total Burden on CT = Lead Burden+ Relay Burden 10 VA.7096 For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden As meter used is Multifunction type.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear. 0.1 Vk>= 40Rct+175V. CL-0.1A is <=4 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA. 2B For Differential Protection Motor rated Current = 1100/Sqrt(3)/6.2 1 2 Total Burden on CT = Lead Burden+ Meter Burden Lead Burden for lead length of 40M= I2x(Rct+2RL) 4 i.87X0.7096 6. Rct Assumed for CT Sec.7096 6. Also Rct is max typical value for 750Amp Primary 800 87.1A is <=6 ohm 6.1 =Sqr(1)*(Rct+2Rl) =Rct+0.7096 As relay used is numerical(SPAJ-140C) type.7096 Rct Assumed for CT Sec.66V ii.9096 FD-2A.995 R relay = 0.1) = 40Rct+163.3 i.225 (Considering 225m Length from Motor terminal to Relay)=1.5 9.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA. CL5P20 ii.6/0.67 = 40*1*(Rct+2x1.1A is 6 ohm for 750/1Amp 6. Rct Assumed for CT Sec. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear. Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) As meter used is Multifunction type.5 9. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.8096 As relay used is numerical(SPAJ-140C) type.8096 As relay used is numerical(SPAJ-140C) type. CL-0.96V ii.1 Vk>= 40Rct+80V. CL-0.66 = 40*1*(Rct+2x0.1A is 4 ohm for 100/1Amp 4. CL5P20 iii.7096 Rct Assumed for CT Sec. 5. 1600 200/1 164.1A is <=5 ohm 5.1A is <=1 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.7096 Rct Assumed for CT Sec. 2B For Differential Protection Motor rated Current = 1100/Sqrt(3)/6.7096 1. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use 0.5 6 i.74 50/1 3C x 185 mm2 0.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.7096 Total Burden on CT = Lead Burden+ Relay Burden 10 VA. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.887+0.9096 As meter used is Multifunction type.1 =Sqr(1)*(Rct+2Rl) =Rct+0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear. Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0.887 R relay = 0. 2E.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA. 2B.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) As meter used is Multifunction type. 400 43.1A is 5 ohm for 200/1Amp 5. 8.1 (Considering 100m Length from Motor terminal to Relay)=0. 2F For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden Lead Burden for lead length of 40M= I2x(Rct+2RL) Rct Assumed for CT Sec.Lead Burden for lead length of 40M= I2x(Rct+2RL) 5 i. 2C.2 1 2 Page 16 of 20 .7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA. RL = 8.1) = 40Rct+74. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0.5 7.7096 1.7096 Rct Assumed for CT Sec.9096 PA-2A.87X0. 2D. Coal Mill-2A. CL5P20 ii. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.6/0. =Sqr(1)*(Rct+2Rl) =Rct+0. 2000/1 5400 600/1 524.7096 Rct Assumed for CT Sec. 1400 200/1 3C x 185 mm2 144.1A is 5 ohm for 200/1Amp 5.4836+0.7096 Rct Assumed for CT Sec. Im<=30mA at Vk/2 Or CT details will be same as earlier Supplied CT.6 kV Station switchgear (C1A & C1B) comprising of the following panels with ratings and accessories as indicated in single line diagram. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear. For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use 0.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.9096 CWP-2A.4836 R relay = 0.1 Vk>= 40Rct+210V. For Differential Protection Motor rated Current = 5400/Sqrt(3)/6. Rct Assumed for CT Sec.8096 As relay used is numerical(SPAJ-140C) type.2 1 2 Total Burden on CT = Lead Burden+ Meter Burden Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.1A is <=5 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA.87X0.6/0.7096 5. specification & data sheet.86 Page 17 of 20 . hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.79 300/1 10 Spare motor feeder on Unit-2 buses 5400 590.7096 Lead Burden for lead length of 40M= I2x(Rct+2RL) 7 i.68V RL = 8.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) As meter used is Multifunction type. CL-0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.08 = 40*1*(Rct+2x2.9096 As meter used is Multifunction type. feeder C 6.5 4.Total Burden on CT = Lead Burden+ Meter Burden =Sqr(1)*(Rct+2Rl) =Rct+0.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA.79 300/1 300/1 CT Details same as Unit service Trans.9 i. CL-0.5 8.79 219. ii.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA.47 600/1 CT Details same as I/C feeder from Unit Transformer CT Details same as Station Service transformer feeder to SST Transformer CT Details same as Feedpump Motor feeder 11 12 Spare transformer feeder on Unit-2 buses ESP Service Transformer Feeder-2A & 2B feeder 2500 2500 219.28 (Considering 280m Length from Motor terminal to Relay)=2. iii. 2B For Differential Protection Motor rated Current = 1100/Sqrt(3)/6. CL5P20 5. 8 Main Incomer from Unit Aux transformer 9 Unit Service Transformer-2A & 2B 2500 219. 1 BFP-1C & 2C Motor Feeder From C1A & C2A Board Respct.6/0.1) = 40Rct+202.1A is 5 ohm for 50/1Amp 1. RL = 8. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.6/0.87X0.7983+0. Transformer Page 18 of 20 .7096 Rct Assumed for CT Sec.7983 R relay = 0.5 7. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.864V ii.9096 As meter used is Multifunction type.9096 Tie to U1A As meter used is Multifunction type.67 100/1 0.8096 As relay used is numerical(SPAJ-140C) type.1A is 7 ohm for 750/1Amp 7.1 Vk>= 40Rct+70V. CL-0.5 2 i.7096 Rct Assumed for CT Sec.09 (Considering 90m Length from Motor terminal to Relay)=0.7096 4.7096 7.Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) = 40*1*(Rct+2x0.9 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 10.1A is 4 ohm for 750/1Amp 4.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 15 VA.8096 As relay used is numerical(SPAJ-140C) type.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA. 2000/1 CT Details same as Unit Switchgear I/C feeder from Unit Aux.7096 Rct Assumed for CT Sec. Compressor Feeders From C1A & C2A Board Motor rated Current = 5400/Sqrt(3)/6. Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) 3 =Sqr(1)*(Rct+2Rl) =Rct+0. CL5P20 iii. CL-0.1A is 4 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA.1) = 40Rct+63.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0. 500 54. ii.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.1A is 7 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA.7096 Rct Assumed for CT Sec. 7. hence 15 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear. CL5P20 4. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0. 87X0.864V As meter used is Multifunction type.87X0.548 R relay = 0. CL5P20 5.79 300/1 140.67 100/1 2500 219.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) 144. BFP-2C Motor Feeder From C2B Board For Differential Protection Motor rated Current = 5400/Sqrt(3)/6. Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0.1) = 40Rct+67.84V ii.9096 6 7 8 Tie to U1B Spare feeder CWPT-1 feeder From C1B Board 9 Incomer D 6.67 300/1 5 CWP-1C From C1B Board 1400 153. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.09 (Considering 90m Length from Motor terminal to Relay)=0.7096 5.1) = 40Rct+287. For Differential Protection Motor rated Current = 1100/Sqrt(3)/6.86 RL = 8.67 2000/1 2500/1 300/1 2500/1 2000/1 300/1 100/1 1600 500 5400 600/1 CT Details same as Other Station service Switchgear 7Rx1Cx630 mm2 CT Details same as above air compressor Feeder.6 kV Station switchgear (C2A & C2B) comprising of the following panels with ratings and accessories as indicated in single line diagram.7096 Rct Assumed for CT Sec.1 Page 19 of 20 . For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0.7983+0. 2500 219.79 2000/1 300/1 300/1 2500/1 500 54.67 54.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0.08 = 40*1*(Rct+2x3.7096 Rct Assumed for CT Sec.9 Differential CT for Motor Protection Vk = 40xIx(Rct+2RL+ Rrelay) = 40*1*(Rct+2x0.5 8. specification & data sheet.6/0.4 SST-1 feeder From C1A Board 1600 140. iii. 3Rx1Cx630 mm2 524.4 (Considering 400m Length from Motor terminal to Relay)=3.887 R relay = 0.1A is 5 ohm for 200/1Amp 5. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 10 VA.548+0. 1 Compressor Feeder From C2A Board 2 CWPT-2 feeder From C2A Board 3 4 5 6 7 8 9 Tie to U2A Incomer Spare feeder Incomer Tie to U2B SST-2 feeder From C2B Board Compressor Feeder From C2B Board 10 i. CT ratio is kept same as to maintain the uniformity with Station Service Transformer CT Details same as Other Station service Switchgear RL = 8.8096 As relay used is numerical(SPAJ-140C) type.1 Vk>= 40Rct+290V. CT Details same as Other Station service Switchgear 5Rx1Cx630 mm2 7Rx1Cx630 mm2 3C x 240 mm2 7Rx1Cx630 mm2 5Rx1Cx630 mm2 3C x 240 mm2 CT Details same as above air compressor Feeder.1A is <=5 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA.2 1 2 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0. CL-0.6/0.09 200/1 i. Im<=30mA at Vk/2 For O/C & E/F Protection R relay in ohm (from relay catalogue of ABB model SPAJ) Total Burden on CT = Lead Burden+ Relay Burden 0.ii.7096 Rct Assumed for CT Sec.7096 Lead Burden for lead length of 40M= I2x(Rct+2RL) Rct Assumed for CT Sec.8096 As relay used is numerical(SPAJ-140C) type.7096 Total Burden on CT = Lead Burden+ Meter Burden+burden margin Consider for future use 15 VA. 600/1 CT Details same as earlier main Feeder Page 20 of 20 . CL5P20 7. hence 15 VA considered is more than Sufficient also Lead burden is less than above assumed buden as Meter & CT are at the same Switchgear.5 11 Spare feeder 10. CL-0.1 Lead Burden for lead length of 40M= I2x(Rct+2RL) =Sqr(1)*(Rct+2Rl) =Rct+0. Vk>= 40Rct+70V.9096 As meter used is Multifunction type. For Metering Core Typical Meter burden in ohm (from catalogue of Conzerv model) Typical Anolgue Meter burden in ohm (from catalogue of AE/Rishab) & Transducer Burden margin Consider for future use Total Burden on CT = Lead Burden+ Meter Burden 0.2 1 2 =Sqr(1)*(Rct+2Rl) =Rct+0. hence 10 VA considered is more than Sufficient also Lead burden is less than above assumed buden as relay & Ct are at the same Switchgear.1A is 7 ohm Total Burden on CT = Lead Burden+ Relay Burden 10 VA. iii.7096 7.1A is 7 ohm for 750/1Amp 7.
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