Mitsubishi NF-C Series, Technical Notes

Page 1: ...ADVANCED AND EVER ADVANCING MOULDED CASE CIRCUIT BREAKERS TECHNICAL NOTES 00 A...

Page 2: ...ranch Circuits 57 7 3 For Main Circuit 58 7 4 For Welding Circuits 58 7 5 For Transformer Primary Use 60 7 6 For Capacitor Circuits 61 7 7 For Thyristor Circuits 62 7 8 Selection of MCCBs in inverter...

Page 3: ...ogressive Super Series an integration of technol ogy and know how from this comprehensive electronic product manufacturer will create its own fields of ap plication with its excellent performance A Br...

Page 4: ...urrent of the fixed lower conductor Pressure which works on the movable conductor by gas generated in the slot Lower fixed contact conductor Repulsive force Movable contact Attractive force Current A...

Page 5: ...SW PSW Input and output I Instantaneous circuit CV Constant voltage circuit Phase selection sampling circuit Short time delay soft ware Trigger circuit Over current indication LED Pre alarm indication...

Page 6: ...NF250 HP NF250 SEP NF250 HEP NF400 SP NF400 SEP NF400 HEP NF400 REP NF630 SP NF630 SEP NF630 HEP NF630 REP NF800 SEP NF800 HEP NF800 REP NF1000 SS NF1250 SS NF1600 SS NF50 CP NF60 CP NF100 CP NF250 C...

Page 7: ...ercurrent flows 4 Contact On Mechanism Even in the worst case in which welding occurs owing to an overcurrent the breaker will trip and the handle will maintain to ON indicating the energizing state O...

Page 8: ...isual indication of the tripped condition Also auto trip is trip free so that the handle cannot be used to hold the breaker in the ON condition The protective contact opening func tion cannot be defea...

Page 9: ...nt undergoes full phase rectification in the rectifier circuit 3 After rectification each of the currents are converted by a peak conversion and an effective value conversion circuit 4 The largest pha...

Page 10: ...ing Negligible effect up to 630A Above that operating current decreases due to increase of a fever IF distortion is big minimum operating cur rent increases Distorted wave Electronic type Within the r...

Page 11: ...ie down on the grids breaking up into a series of smaller arcs and also being cooled by the grid heat conduction The arc being effectively longer thus requires far more voltage to sustain it and being...

Page 12: ...te while a certain load current is already flowing Where the MCCB is assumed to be at 50 of rat ing when the overload occurs the parameter is called the 50 hot state characteristic if no percentage is...

Page 13: ...rent Tripping time AC DC Tripping time Overcurrent 4 5 Frequency Characteristics At commercial frequencies the characteristics of Mitsubishi MCCBs of below 630A frame size are vir tually constant at b...

Page 14: ...thstand capabilities given below Table 4 4 The impulse voltage is defined as sub Table 4 3 MCCB Switching Endurance Frame size 100 or less 225 400 630 800 1000 2000 2500 3000 3200 4000 Operations per...

Page 15: ...tage protector it must be coordinated with an MCCBs on the secondary side Generator Generator Protection MCCBs These MCCBs have long time delay operation shorter than standard type and low instantaneo...

Page 16: ...mpere rating and instantaneous NF30 SP 3 5 10 15 20 30 600 2 5 1 2 5 1 5 2 5 2 2 3 2 3 Magnetic Fixed ampere rating instantaneous 50 10 15 20 30 40 50 600 2 5 1 2 5 1 5 2 5 2 2 3 Hydraulic magnetic Fi...

Page 17: ...Inst A 50 Hydraulic magnetic Fixed ampere rating and instantaneous Magnetic Fixed ampere rating and instantaneous NF50 HP 10 15 20 30 40 50 600 7 5 4 10 5 10 5 25 13 2 3 4 2 3 4 60 NF60 CP 10 15 20 3...

Page 18: ...tantaneous 2 3 50 300 60 60 360 72 75 450 90 100 600 120 2 3 4 2 3 Magnetic Fixed ampere rating and instantaneous NF100 CP NF100 SP 15 20 30 40 50 60 75 100 690 15 8 25 13 30 15 50 25 2 3 4 50 60 75 1...

Page 19: ...63 600 120 63 80 945 189 80 100 1200 240 50 NF50 HRP Thermal magnetic Fixed ampere rating and instantaneous 15 225 45 20 300 60 30 450 90 40 600 120 50 750 150 2 3 Magnetic Fixed ampere rating and ins...

Page 20: ...25 225 100 1500 300 Magnetic Fixed ampere rating and instantaneous 2 3 4 Rated insulation voltage Ui V AC 5 3 30 15 50 25 50 25 100 50 2 3 4 690 15 20 30 40 50 60 75 100 Rated current In A 15 20 20 25...

Page 21: ...haracteristics must be adjusted as follows STD q 3 Is setting LTD minimum setting TL 12sec setting Electronic trip relay Adjustable ampere rating Adjustable long time delay operating time short time d...

Page 22: ...160 NF160 SP 125 150 160 690 15 8 25 13 30 15 50 25 2 3 4 Thermal magnetic Fixed ampere rating and instantaneous Magnetic Fixed ampere rating and instantaneous 125 1250 250 160 1600 320 NF160 SP T A 1...

Page 23: ...200 2800 560 225 3150 630 250 2500 500 2 3 Thermal magnetic Fixed ampere rating and instantaneous 6 In 4 In 125 750 150 500 100 150 900 180 600 120 175 1050 210 700 140 200 1200 240 800 160 225 1350 2...

Page 24: ...00 300 175 1750 350 200 2000 400 225 2250 450 250 2250 450 Rated insulation voltage Ui V AC Rated current In A 690 15 8 25 13 30 15 50 25 2 3 4 125 150 175 200 225 250 NF250 SP T A 100 125 125 160 150...

Page 25: ...current In A 100 125 125 160 150 200 200 250 690 5 3 30 8 50 13 50 13 100 25 2 3 4 Thermal magnetic Adjustable ampere rating and fixed instantaneous 100 125 1400 280 125 160 1400 280 150 200 2100 420...

Page 26: ...250 HEP 125 250 690 5 3 30 8 50 13 50 13 100 25 3 4 3 Electronic trip relay Adjustable ampere rating Adjustable long time delay operating time short time delay pick up and instantaneous Short time del...

Page 27: ...1500 1800 2100 2400 3000 350 700 875 1050 1225 1400 1750 2100 2450 2800 3500 400 800 1000 1200 1400 1600 2000 2400 2800 3200 4000 Instantaneous pick up current Variation is within 15 of setting curren...

Page 28: ...00 adjustable 3 Electronic trip relay Adjustable ampere rating Adjustable long time delay operating time short time delay pick up and instantaneous Short time delay pick up current Variation is within...

Page 29: ...800 1000 1200 1400 1600 2000 2400 2800 3200 4000 500 1000 1250 1500 1750 2000 2500 3000 3500 4000 5000 600 1200 1500 1800 2100 2400 3000 3600 4200 4800 6000 630 1260 1575 1890 2205 2520 3150 3780 441...

Page 30: ...table 3 Electronic trip relay Adjustable ampere rating Adjustable long time delay operating time short time delay pick up and instantaneous Short time delay pick up current Variation is within 15 of s...

Page 31: ...ay operating time short time delay pick up and instantaneous Short time delay pick up current Variation is within 15 of setting current 2 to 10 Ir 400 800 1000 1200 1400 1600 2000 2400 2800 3200 4000...

Page 32: ...000 2500 3000 3500 4000 5000 600 1200 1500 1800 2100 2400 3000 3600 4200 4800 6000 700 1400 1750 2100 2450 2800 3500 4200 4900 5600 6300 800 1260 1575 1890 2205 2520 3150 3780 4410 5040 6300 Instantan...

Page 33: ...3 3 4 3 4 Solid state Adjustable ampere rating Adjustable instantaneous pick up 3 4 Variation is within 10 of the setting current 5 7 5 10 In 3 4 5 6 In 2 3 4 In 500 2500 3750 5000 1500 2250 3000 1000...

Page 34: ...3 4 3 4 Solid state Adjustable ampere rating Adjustable instantaneous pick up 3 4 Variation is within 10 of the setting current 5 7 5 10 In 3 4 5 6 In 2 3 4 In 600 3000 4500 6000 1800 2700 3600 1200 1...

Page 35: ...atic tripping device Rating A and Inst A Number of poles Automatic tripping device Rating A and Inst A Solid state Adjustable ampere rating Adjustable short time delay pick up Fixed instantaneous pick...

Page 36: ...0 1400 1500 1600 690 25 13 65 33 85 43 85 43 125 63 3 4 3 4 Solid state Adjustable ampere rating Adjustable instantaneous pick up 3 4 Variation is within 10 of the setting current 3 4 5 6 In 2 3 4 In...

Page 37: ...up and fixed instantaneous pick up 3 4 2500 NF2500 S 2500 600 65 50 85 50 85 50 125 85 3 Thermal adjustable magnetic Fixed ampere rating and adjustable instantaneous 3 Adjustable magnetic Fixed ampere...

Page 38: ...0 3000 600 65 50 85 50 85 50 125 85 3 Adjustable magnetic Fixed ampere rating and adjustable instantaneous Short time delay pick up current Variation is within 10 of the setting current 2 3 4 In 1800...

Page 39: ...ing device Rating A and Inst A 3 NFE4000 S 2500 3000 3500 4000 600 65 50 85 50 85 50 125 85 3 Adjustable magnetic Fixed ampere rating and adjustable instantaneous Variation is within 10 of the Hi sett...

Page 40: ...uption requires that in the event of a fault only the device directly before the fault will trip and that other branch circuits of the same or higher level will not be affected The range of selective...

Page 41: ...REP NF225 UP NF630 REP NF630 CP NF800 CEP NF225 RP 200 NF30 SP 3ph trans capacity kVA Interrupting capacity kA sym 1ph trans capacity kVA NF100 SP NF100 SEP NF1000 SS NF1600 SS NF2000 S NF4000 S NFE2...

Page 42: ...NST pickup current are to be set to the maxi mum values 2 When selecting the over current range also check the conformity using the other characteristic curves Main breaker STD pick up current Set up...

Page 43: ...0 50 85 100 125 5 1 6 1 6 3 5 3 5 5 5 5 5 5 5 5 5 25 1 6 1 6 3 5 3 5 10 10 20 20 20 20 20 25 85 3 5 3 5 10 10 20 20 20 65 65 85 50 3 5 3 5 7 5 7 5 15 15 15 15 15 50 100 3 5 3 5 10 10 25 25 25 25 25 10...

Page 44: ...F100 HEP NF50 HP NF60 HP Icu kA 25 50 25 50 42 65 42 65 36 42 65 85 2 5 1 6 1 6 2 5 2 5 2 5 2 5 2 5 2 5 2 5 2 5 2 5 2 5 10 1 6 1 6 3 5 3 5 7 5 7 5 10 10 10 10 10 10 30 3 5 3 5 7 5 7 5 15 15 15 18 18 3...

Page 45: ...50 20 65 20 65 20 65 18 7 50 18 7 50 18 7 65 18 7 65 18 7 50 18 7 65 18 7 65 AE1600 SS 65 25 50 50 65 65 50 65 42 50 42 50 65 65 30 30 42 50 42 50 65 65 42 50 65 30 50 30 65 30 65 30 65 24 50 24 50 24...

Page 46: ...8 7 65 18 7 50 18 7 65 18 7 65 AE1600 SS 65 10 30 30 50 50 25 50 25 25 42 50 42 50 15 15 25 25 42 50 42 50 25 25 50 24 25 24 42 24 42 24 65 24 50 24 50 24 65 24 65 24 50 24 65 24 65 AE2000 SS 85 10 30...

Page 47: ...00 85 85 85 65 65 65 65 65 65 65 125 200 200 200 200 65 35 50 50 35 50 50 35 50 50 125 200 85 85 85 65 65 65 65 65 65 125 200 200 200 200 65 65 65 65 65 65 65 200 200 200 65 65 65 65 200 200 10 14 5 5...

Page 48: ...200 200 100 100 100 200 200 200 100 100 100 100 200 200 100 35 50 10 10 10 10 7 5 125 200 35 50 35 85 50 50 50 50 50 50 50 50 50 50 30 30 125 200 85 125 50 50 50 50 50 50 50 50 50 50 50 50 35 35 125...

Page 49: ...rent asym peak NF100 RP NF100 UP NF225 RP NF225 UP short circuit current sym r m s kA 3 10 20 50 100 200 100 200 50 30 20 10 5 1 Max Iet through current kA NF225 UP NF225 RP NF100 UP NF100 RP Prospect...

Page 50: ...to larger wires Table 6 4 is restrictive in that e g in a circuit of fault capacity of 5000A or more 2 5mm2 wires would not be permitted In practice the impedance of the con ductor itself presents a l...

Page 51: ...e short time limitation for wiring with heat proof vinyl or styrene butadene rubber insulation Current transpositions for the range of wire sizes are not presented being non standard however Fig 6 15...

Page 52: ...00 300 400 600 800 10 20 30 40 60 80 1 0 8 100 1000 10000 100000 Current A d 400A fream MCCB Tripping time s 0 6 0 5 2 3 4 6 8 2000 1000 100 200 300 400 600 800 10 20 30 40 60 80 1 0 8 10 100 1000 100...

Page 53: ...cognized in which case the manufacturer shall indicate the measures to be taken as regards the maintenance of the equip ment Fig 6 18 Protective Coordination MCCBs and Motor Starters MCCB Magnetic con...

Page 54: ...rrangement should be reserved for applica tions requiring infrequent motor starting and stopping 6 7 6 Motor Starting Current Motor starting times of up to 15 seconds are generally considered safe mor...

Page 55: ...about one half cycle followed by a rapid decrease to normal starting current level From the curves it can be concluded that peak inrush mag nifications vary greatly depending on the duty involved for...

Page 56: ...taneous trip region can be regarded as the same as the tripping characteristics Further there is very little tolerance variation between units thus the tripping characteristics can be shown as a singl...

Page 57: ...urves with no danger of overlap 3 h 2 1 h 40 30 20 10 min 6 4 2 6 0 6 0 4 0 2 0 1 0 06 0 02 0 01 0 006 0 004 0 002 4 2 1 min 30 20 10 s 1 s Time 150 300 600 1 000 4 000 10 000 40 000 80 000 200 400 80...

Page 58: ...ponent attendant to the low power factor about 0 3 of the starting current For delta start ing the unphased switching allowance increases the 1 4 margin to 1 9 For running restarting the unphased swit...

Page 59: ...welder intermittent current into a ther mal equivalent continuous value Ie consider the current waveform Fig 7 4 load resistance R gives power dissipation W I1 2 Rt1 and average heat produced t1 t2 W...

Page 60: ...ure a transient surge current will flow due to the super imposed DC component and the saturation of the transformer core In order to prevent spurious tripping of protective devices resulting from such...

Page 61: ...of rated voltages to rated taps it should be noted that supply overvoltage will result in even larger surges Since it is the instantaneous trip function of the MCCB that responds to the transient cur...

Page 62: ...MCCB contacts are not suffi ciently open an arc will reappear across the gap re sulting in an oscillatory capacitor discharge at a fre quency determined by the circuit reactance includ ing the capacit...

Page 63: ...taneous trip current of greater than M2 6200 4400A is recommended for an adequate safety margin Such an MCCB will be rated at 600A Accordingly in this example the Type NF630 SP rated at 600A is select...

Page 64: ...ent leads to excessive tempera ture rise of the thyristor junction resulting in loss of the control function and thermal destruction A fault therefore must be interrupted as quickly as possible before...

Page 65: ...rent RMS current RMS current Current waveform Current waveform Circuit diagram Current flow MCCB1 MCCB2 IP 2 IP 2 IP 2 IP IP IP IP 6 6 0 552 IP IP 1 4 M3 3 6 2 45 IF IF 1 2 M3 3 6 0 817 ID ID 1 3 2 M3...

Page 66: ...current rise rate di dt on the load side In the short circuit of Figs 7 15 and 7 16 the current is i 1 R E t L R and the current rise rate di dt is t 0 dt di L E Thus the inductance of the line and th...

Page 67: ...tection is effected provided that the ei2dt limit for the element is larger than that for the MCCB interruption duration This must be es tablished by test Fig 7 19 High Speed Fuses for Thyristor Circu...

Page 68: ...of the stable running current In the cases of constant power or flickerless types the determining factor is the normal running current which is higher than the starting cur rent For MCCB selection th...

Page 69: ...proved by inputting DC reactor DCL or AC reactor ACL Further in the case of the output current waveform in Fig 7 29 the PWM generates higher harmonic wave components than that of the PAM This table is...

Page 70: ...value Mean value Peak factor Max value RMS value Circuit with ACL Large ACL Small With DCL Input current Power factor Below 58 7 58 7 58 7 83 5 83 5 83 5 95 3 95 3 1 23 1 28 Above 1 99 1 99 1 99 1 27...

Page 71: ...rsely affect perfor mance service life insulation and other aspects of MCCB quality Where service conditions differ sub stantially from the specified range as below derating of performance levels may...

Page 72: ...r the breakers of added corrosionproof type corrosion proof plating is applied to the metal parts Where concentration of corrosive gas exceeds the level stated below it is necessary to use MCCB of add...

Page 73: ...Shock Withstand Characteristics of Mitsubishi MCCB Line terminals Line terminals Fig 8 2 Drop Test Attitudes Type BH K BH P BH S BH PS BH D MB30 CS MB30 SP MB50 CP MB50 SP MB100 SP MB225 SP NF30 SP N...

Page 74: ...ort circuit current is cal culated from the impedance on the supply side of the breaker Fig 9 1 represents a summary of Japanese standards 9 3 Impedances and Equivalent Circuits of Circuit Components...

Page 75: ...e given as Cable size mm2 Resistance m m 2 or 3 core cables 1 core cables close spaced 1 core cables 6cm spaced 2 or 3 core cables 1 core cables close spaced 1 core cables 6cm spaced 1 5 2 5 4 0 6 0 1...

Page 76: ...hase Equivalent Circuits Table 9 4 Total Impedances for 3 Phase Power Supplies 50 75 100 150 200 300 500 750 1000 1500 2000 Impedance based on 1000kVA Ohmic value m Transformer capacity kA Notes 1 Tot...

Page 77: ...such as an MCCB or fuse is employed the DC component must be considered Further the mechanical stress of the electric circuit will be affected by the maximum instantaneous short circuit current hence...

Page 78: ...e Impedance Ohmic method impedance method Remarks Ias K3 Is Eq 4 Key Is V Z Ias P Z IB K3 3 phase short circuit current A sym Line line voltage V Circuit impedance 1 phase component 3 phase short circ...

Page 79: ...RL jXL 0 0040 j0 0999 Is 35 622 A x 100 M3 x 440 x3 683 1000 x 103 ZL 0 0436 1000 x 106 6600 2 ZL 1 741 j43 525 x 2 6600 440 ZL x 100 x 10 2 x 103 0 1936 m 1000 x 106 4402 ZT x 1 23 j5 41 x 10 2 1 29...

Page 80: ...OKYO 100 8310 TELEX J24532 CABLE MELCO TOKYO Y 0525 C 0007 ROD Printed in Japan Made from recycled paper Revised publication effective July 2000 Specifications subject to change without notice Be sure...