High speed fuses - Cooper · PDF filemain fuse. Indicator fuses can ... Time-current curve 10 4 10 3 10 2 10 –1 ... High speed fuses 6 BUSSMANN SERIES FULL LINE CATALOG 1007—July

6-94 BUSSMANN SERIES FULL LINE CATALOG 1007—July 2015 Eaton.com/bussmannseries

6 High speed fusesBritish BS 88

General information

Designed and tested to:• BS 88: Part 4• IEC 269: Part 4• UL Recognized

Eaton offers the industry’s widest range of British style semiconductor fuses and accessories.Eaton’s Bussmann series British style products use innovative arc quenching techniques and high grade materials to provide:• Minimal energy let-through (I2t)• Excellent DC performance• Good surge withstand profile

British style fuses are typically found in equipment manufactured in the United Kingdom or BritishCommonwealth countries. However, North American manufacturers have begun to specify British style fuses —particularly in UPS applications at 240V or less — to takeadvantage of their size, performance and cost benefits.

Voltage rating

All Bussmann series British style fuses are tested to IEC 269:Part 4. This standard requires a test voltage which is 5%higher than the rated voltage. In North America, fuses arerequired to clear only their rated voltage.

Accessories

Trip-indicator fuses are available for use in parallel with themain fuse. Indicator fuses can be attached to the associatedfuselink, or mounted separately in panel-mounted fuseclips.In addition, a push-on adapter and microswitch attachmentare available, to provide remote indication. Fuse blocks arealso available for most applications.

Introduction

British BS 88 contentsFuse Ampvolts range Page240 6-900 6-95690 6-710 6-98

AccessoriesIndicator system and fuse bases 6-102

British BS 88 fuse ranges

Amps Vac Vdc6-900 240 1506-710 690 500

6-95

High speedfuses

6High speed fusesBritish BS 88

BUSSMANN SERIES FULL LINE CATALOG 1007—July 2015 Eaton.com/bussmannseries

Arc voltage

This curve gives the peakarc voltage, UL, whichmay appear across thefuse during its operationas a function of theappliedworking voltage, Eg, (rms)at a power factor of 15%.

Power losses

Watts loss at rated currentis given in the electricalcharacteristics. The curveallows the calculation ofthe power losses at loadcurrents lower than therated current. The correction factor, Kp, isgiven as a function of theRMS load current, Ib, in %of the rated current.Catalog numbers

Electrical characteristicsRated I2t (A2 sec)

Catalog current Clearing Clearing Wattsnumbers Type RMS-amps Pre-arc at 120V at 240V loss6LCT 6 2 6 9 1.010LCT 10 3.8 12 22 2.512LCT LCT 12 7 22 32 2.516LCT 16 20 50 100 2.520LCT 20 25 80 160 4.025LET 25 18 120 250 4.032LET 32 32 200 450 5.035LET 35 50 320 600 5.050LET 50 100 500 1400 7.063LET LET 63 180 1100 2200 9.080LET 80 300 1900 3800 10.0100LET 100 600 3800 7500 10.0125LET 125 600 3800 7500 16.0160LET 160 1100 7000 16000 20.0180LETa 180 1600 12000 29000 21.0160LMT 160 1100 7000 16000 17.0200LMT 200 1500 10000 20000 28.0250LMT 250 3200 20000 40000 28.0315LMT LMT 315 6000 35000 75000 35.0355LMT 355 8000 50000 100000 35.0400LMT 400 14000 70000 160000 40.0450LMT 450 18000 100000 220000 42.0400LMMT 400 6000 35000 80000 60.0500LMMT 500 14000 80000 170000 64.0630LMMT LMMT 630 24000 150000 300000 75.0710LMMT 710 32000 200000 460000 77.0800LMMT 800 52000 300000 600000 82.0900LMMT 900 75000 400000 800000 97.0

• Watts loss provided at rated current.• Note: 7LET, 10LET, 12LET and 16LET are available for replacement purposes on existing

equipment.• See accessories on page 6-102.

Features and benefits• Excellent cycling capability• Excellent DC performance• Low arc voltage and low

energy let-through (I2t)

5641.826.2

17.7

19.1

12.7

7.1

9.7

Fig. 2: LET

473828

6.4

8.48.7

4

5.5

Dimensions - mmFig. 1: LCT

1mm = 0.0394” / 1” = 25.4mm

LCT, LET, LMT, LMMT – 240V: 6-900A

SpecificationsDescription: BS 88 style stud-mount fuses.Dimensions: See dimensionsillustrations.Ratings:Volts: — 240Vac/150Vdc

Amps: — 6-900AIR: — 200kA RMS Sym.

Agency information: CE, Designed and tested to: BS 88Part 4, IEC 269 Part 4, UL Recognized. All fuses above havebeen tested at 318Vac. Consult Eaton for specific ULRecognition status.

Electrical characteristics

Total clearing I2t

The total clearing I2t at ratedvoltage and at power factorof 15% are given in the electrical characteristics. Forother voltages, the clearingI2t is found by multiplying bycorrection factor, K, given asa function of applied workingvoltage, Eg, (rms).

845931

83

38

25.4

13.510.3

0.20.40.60.81.01.21.41.6

10050 150 200 250

1)

2) Eg

K

845931

41

38.1

25.4

10.313.5

Fig. 3: LMTFig. 4: LMMT

Indicator (Optional)

1) LCT2) LET, LMT, LMMT

Kp1.00.8

0.40.50.6

0.3

0.2

0.130 40 50 60 70 80 90 100%

Ib

750

500

250

100 200 300

1)

2)

Eg

UL

1) LCT2) LET, LMT, LMMT

Typical applications• DC common bus• AC and DC drives• Power converters/rectifiers• Reduced voltage starters

Data Sheet: 720004

Peak let-through curve

LET 25-180A: 240V

Time-current curve

LCT 6-20A: 240V

Time-current curve

104

103

102

10–1

10–2

10–3

10–4

Prospective Current In Amps RMS

Virtu

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e-Ar

cing T

ime

In S

econ

ds

2 4 6 8 101 22 4 6 8 2102 2 4 6 8 103

2

46

2

64

100

2

64

101

2

64

2

64

2

64

64

2

6

2

4

20LCT16LCT12LCT10LCT6LCT

104

103

102

101 22 4 6 8 2102 2 4 6 8 103

2

46

2

64

100

2

64

101

2

64

2

64

2

64

64

2

6

2

4


Virtu

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cing

Time

In S

econ

ds

63LET50LET35LET32LET25LET

180LETa160LET125LET100LET 80LET

10–4

10–3

10–2

10–1

Prospective Short-Circuit Current Symmetrical RMS101 1022 64 2 4 6 103 2 4 6 104 2 4 6 105

Peak

Let

-Thr

ough

Cur

rent

101

6

2

4

2

102

4

6

2

103

6

4

104

6

4

2

2

105

SYMMETRICAL FAULTFULLY ASYMMETRICAL FAULT

20LCT16LCT12LCT10LCT 6LCT


80LET125 & 100LET

160LET & LMT200LMT180LET

250LMT315LMT355LMT

400 & 500LMMT450LMT

630LMMT710LMMT800LMMT900LMMT



Data Sheet: 35785296 Data Sheet: 35785293

6-97

High speedfuses



10–4

10–3

10–1

102

102 22 4 6 8 2103 2 4 6 8 104

2

46

2

64

100

2

64

101

2

64

2

64

2

64

64

2

6

2

4

104

315LMT

450LMT400LMT355LMT

250LMT200LMT160LMT


Virtu

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e-Ar

cing T

ime

In S

econ

ds

103

10–2

10–1

10–3

10–2

102

103

104

102 22 4 6 8 2103 2 4 6 8 104

2

46

2

64

100

2

64

101

2

64

2

64

2

64

64

2

6

2

4


Virtu

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e-Ar

cing T

ime

In S

econ

ds

10–4

710LMMT

900LMMT800LMMT

630LMMT500LMMT400LMMT

Prospective Short-Circuit Current Symmetrical RMS101 1022 64 2 4 6 103 2 4 6 104 2 4 6 105

Peak

Let

-Thr

ough

Cur

rent

101

6

2

4

2

102

4

6

2

103

6

4

104

6

4

2

2

105

SYMMETRICAL FAULTFULLY ASYMMETRICAL FAULT

20LCT16LCT12LCT10LCT 6LCT


80LET125 & 100LET

160LET & LMT200LMT180LET

250LMT315LMT355LMT

400 & 500LMMT450LMT

630LMMT710LMMT800LMMT900LMMT


LMMT 400-900A: 240V

Time-current curve

LMT 160-450A: 240V

Time-current curve




CT, ET, FE, EET, FEE, FM, FMM, MT, MMT –690V: 6-710A

SpecificationsDescription: BS 88 style stud-mount fuses.Dimensions: See dimensionsillustrations.Ratings:Volts: — 690Vac/500Vdc

Amps: — 6-710AIR: — 200kA RMS Sym.

Agency information: CE, Designed and tested to: BS 88Part 4, IEC 269 Part 4, UL Recognized. MT and MMT —350Vdc (IEC) rating. Consult Eaton for UL Recognition status.

Electrical characteristics

Total clearing I2t

The total clearing I2t at ratedvoltage and at power factorof 15% are given in the electrical characteristics. Forother voltages, the clearingI2t is found by multiplying bycorrection factor, K, given asa function of applied workingvoltage, Eg, (rms).

Dimensions - mmFig. 1: CT

7763.548

17.1

19.1

12.7

7.1

9.7

947046

3719

31.8

8.7

11.9

113A50

41

38.1

25.4

10.3

13.5

113A50

83

38

25.4

10.3

14

Fig. 2: ET, FE

74.664.354.8

6.4

8.78.7

45.5

Fig. 3: EET, FEE Fig. 4: FM, MT Fig. 5: FMM, MMT

1mm = 0.0394” / 1” = 25.4mm Figs. 4 & 5 “A” DimensionsType “A”FM 80-85mmFMM 80-85mmMT 85mmMMT 85mm

Arc voltage

This curve gives thepeak arc voltage, UL,which may appearacross the fuse during itsoperation as a functionof the applied workingvoltage, Eg, (rms) at apower factor of 15%.

Power losses

Watts loss at rated current is given in theelectrical characteristics.The curve allows thecalculation of the powerlosses at load currentslower than the rated current. The correctionfactor, Kp, is given as afunction of the RMS loadcurrent, Ib, in % of therated current.

Features and benefits• Excellent cycling capability• Excellent DC performance• Low arc voltage and low energy let-through (I2t)• Low watts loss

Typical applications• DC common bus• DC drives• Power converters/rectifiers• Reduced voltage starters

1500

1000

500

200 400 600 660Eg

UL

1)

2)

1) CT2) ET, FE, EET, FEE, FM, FMM

200 300 400 500 600 690

0.2

0.4

0.6

0.81.0

1.2

1.4

1.6

1) 2)Eg

K

1) CT, ET, EET, FE, FEE, MT, MMT2) FM, FMM

Kp1.00.8

0.40.50.6

0.3

0.2

0.130 40 50 60 70 80 90 100%

Ib

Data Sheet: 720024

6-99

High speedfuses



103

10–1

2 4 6 8 101 22 4 6 8 2102 2 4 6 8 103

2

46

2

64

100

2

64

101

2

64

2

64

2

64

64

2

6

2

4

10CT12CT16CT20CT

6CT

32ET25ET


Virtu

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ime

In S

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ds

56ET

80ET63ET

45ET40ET35ET

10–4

10–3

10–2

102

104

Prospective Short-Circuit Current Symmetrical RMS

Peak

Let

-Thr

ough

Cur

rent

2

4

2

6

64

2

4

64

2

64

2

6

2 4 6 2 4 6 2 4 6 2 4 6101

102

103

104

105

101 102 103 104 105 2

20CT16CT12CT10CT6CT

80ET63ET56ET45ET40ET35ET32ET25ET

710MMT630MMT560MMT500MMT450MMT

315MT 355MT 400MMT280MT 355MMT250MT 315MMT

280MMT 200MT

180MT 225MMT160MT 200MMT

180MMT

160EET140EET110EET90EET


CT 6-20, ET 25-80A: 690V

Time-current curveElectrical characteristics

Rated I2t (A2 sec)Catalog current Clearing Clearing Wattsnumbers Type RMS-amps Pre-arc at 415V at 660V loss6CT 6 1.8 8.5 12 210CT 10 7 30 48 312CT CT 12 10 40 65 316CT 16 16 66 110 720CT 20 32 150 220 725ET 25 25 150 250 732ET 32 32 190 350 1135ET 35 52 310 500 1140ET ET 40 103 600 900 945ET 45 103 680 1100 1156ET 56 135 950 1500 1463ET 63 171 1200 2000 1680ET 80 360 2500 4000 1835FE 35 33 130 200 940FE 40 52 180 300 945FE 45 76 270 450 1150FE 50 103 380 600 1163FE FE 63 135 480 750 1271FE 71 210 600 950 1780FE 80 250 900 1500 2090FE 90 360 1300 2100 20100FE 100 470 1800 2800 2390EET 90 490 3000 4500 19110EET EET 110 600 4000 6500 27140EET 140 1050 7000 12000 35160EET 160 1500 10000 17000 39100FEE 100 400 1600 2400 24120FEE 120 540 1900 3100 32140FEE FEE 140 850 2500 3800 36160FEE 160 1000 3700 5700 46180FEE 180 1400 5300 8400 46200FEE 200 1900 7100 11400 52180FM 180 1400 7500 13500 40200FM 200 2600 10500 18500 40225FM 225 3700 14500 26500 44250FM FM 250 5200 20500 37500 48280FM 280 7000 30500 55000 48315FM 315 10000 40000 77000 55350FM 350 15000 60000 105000 55400FMM 400 10000 40000 72500 85450FMM 450 15000 60000 105000 90500FMM FMM 500 20000 82000 150000 100550FMM 550 30000 120000 215000 100630FMM 630 45000 180000 310000 100700FMM 700 60000 245000 420000 120160MT 160 2400 15000 25000 26180MT 180 3800 25000 38000 26200MT 200 6000 40000 58000 27250MT MT 250 11500 80000 110000 32280MT 280 16500 100000 150000 35315MT 315 19000 125000 180000 42355MT 355 22000 160000 200000 51180MMT 180 1650 12000 18000 42200MMT 200 2200 16000 23000 42225MMT 225 3700 26000 40000 42280MMT 280 6600 47000 70000 47315MMT 315 8600 62000 91000 51355MMT MMT 355 13500 97000 140000 54400MMT 400 21000 150000 220000 60450MMT 450 30000 220000 320000 57500MMT 500 42000 300000 450000 64560MMT 560 60000 430000 640000 64630MMT 630 68500 500000 720000 86710MMT 710 78000 600000 850000 105

• Watts loss provided at rated current.• Note: FC, 8ET, 12ET, 15ET, 20ET, 65EET and 75EET are available for replacement

purposes on existing equipment.• See accessories on page 6-102.

Data Sheet: 35785312

Catalog numbers



103

104

102

10–1

10–2

2 4 6 8 102 22 4 6 8 2103 2 4 6 8 104

2

46

2

64

100

2

64

101

2

64

2

64

2

64

64

2

6

2

4


Virtu

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In S

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ds


200MT

355MT315MT280MT250MT

180MT160MT

10–4

10–3


Peak

Let

-Thr

ough

Cur

rent

2

4

2

6

64

2

4

64

2

64

2

6

2 4 6 2 4 6 2 4 6 2 4 6101

102

103

104

105

101 102 103 104 105 2

20CT16CT12CT10CT6CT

80ET63ET56ET45ET40ET35ET32ET25ET

710MMT630MMT560MMT500MMT450MMT

315MT 355MT 400MMT280MT 355MMT250MT 315MMT

280MMT 200MT

180MT 225MMT160MT 200MMT

180MMT



EET 90-160A, MT 160-355A: 690V

Time-current curve

104

103

102

10–1

10–3


Virtu

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e-Ar

cing T

ime

In S

econ

ds

102 22 4 6 8 2103 2 4 6 8 104

2

46

2

64

100

2

64

101

2

64

2

64

2

64

64

2

6

2

4

280MMT

355MMT315MMT

225MMT200MMT180MMT

630MMT710MMT

560MMT500MMT450MMT400MMT

10–4

10–2

MMT 180-710A: 690V

Time-current curve



6-101

High speedfuses



104

103

102

10–1

10–2

10–3

10–4

102 22 4 6 8 2103 2 4 6 8 104

2

46

2

64

100

2

64

101

2

64

2

64

2

64

64

2

6

2

4

120FEE140FEE160FEE180FEE200FEE

100FEE

550FMM

700FMM630FMM

500FMM450FMM400FMM


Virtu

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e-Ar

cing T

ime

In S

econ

ds

FEE 100-200A and FMM 400-700A: 690V

Time-current curve


Peak

Let

-Thr

ough

Cur

rent

102 2 4 62

4

6

103

8

2

8

4

6

104

2

4

6

8

103 2 4 6 104 2 4 6 105 2

180FEE

100FEE120FEE140FEE160FEE

200FEE

400FMM450FMM500FMM550FMM630FMM700FMM


103

102

10–1

10–2

10–42 4 6 8 102 22 4 6 8 2103 2 4 6 8 104

2

46

2

64

100

2

64

101

2

64

2

64

2

64

64

2

6

2

4

100FE

35FE40FE45FE50FE63FE71FE80FE90FE

350FM315FM280FM250FM220FM200FM180FM


Virtu

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cing T

ime

In S

econ

ds

10–3

104

FE 35-100A and FM 180-350A: 690V

Time-current curve


Peak

Let

-Thr

ough

Cur

rent

2

4

2

6

64

2

64

2

64

2 4 6 2 4 6 2 4 6 2 4 6101

102

103

104

105

101 102 103 104 105 2

350FM315FM280FM250FM225FM200FM180FM

100FE90FE80FE71FE63FE50FE45FE40FE35FE




6 High speed fusesBritish BS 88 fuse accessories

Indicator system

Trip-indicatorsTrip-indicators are available for use in parallel with themain fuse. They can either be attached to the associatedfuse or mounted separately in panel mounted fuse clips,reference CL1. A push-on adapter and microswitch attachment is available for use with the trip indicator togive the facility of remote indication, reference MAI.Fuse ratings of 20A and below cannot usually accommodate a trip-indicator.When a trip-indicator is to be attached to the main fuse anaccessory pack comprising a pair of mounting clips and anappropriate trip indicator would be required. The clips aresnapped onto the fuse end caps and the indicator ispressed into clips as shown.Electrical specificationsType TI500 TI700Maximum RMS voltage 500 700Maximum peak voltage 700 1000Maximum DC voltage 130 350Cold resistance (ohms) 0.3 0.45Maximum permissible steady-state current 1.5A 1.5AInterrupting capacity (RMS Symm.) 100,000 100,000Pre-Arcing I2t 23 23Total I2t (max volts) 46 46

Microswitch adapter – MAIWe offer a microswitch, complete with adapter for securing the indicator. The microswitch is provided withdouble pole, single throw contacts, having both a normallyopen and a normally closed position. A special material hasbeen employed in the construction of the adapter to provide reliable operation in the range of temperaturesassociated with standard operating conditions and duringfuse operation.

Microswitch and adapter Type MAI

Current rating:AC 50/60Hz resistive load @ 250V RMS 4AAC 50/60Hz resistive load @ 127V RMS 6ADC, resistive load @ 110Vdc 0.7A DCDC, resistive load @ 30Vdc 2A DC

Maximum working voltage:Contact-to-contact (RMS) 1000VContact-to-contact (RMS) 1500V

Maximum DC volts: 110Vdc

Ref. Dim. “A” (mm) RMS voltsTI250 37.6 250TI500 47.5 500TI600 55.7 600TI700 61.8 700TI1100 98.4 1100TI1500 120.6 1500TI2000 147.5 2000TI2500 198.3 2500

RMS For useKit. ref. Details volts with fuse ref.EC-250 Fuse mount 250 LETMC250 Indicator kits 250 LMT and LMMTEC-600 (Includes one 660 FE, FEE and ETMC600 indicator 660 FM and FMMMC700 and two clips) 700 MT and MMT

EC

A

B

D

F6 21 0.8

6.8

6.35

NONC

NCNO

Terminal arrangement

Trip-indicator Dimensions - mm

Dimensions - in mm

Fuse Indicator Kits6.0 8.7

50.8

B

14

CL1 panel mount clips

CL1 panel mount fuse clipsare available for mounting atrip-indicator when mountingdirectly on the fuse is impractical. Order part number CL1.

CL1 panel mount clip Dimensions - mm

Trip indicator

Documents

High speed fuses - Cooper · PDF filemain fuse. Indicator fuses can ... Time-current curve 10 4 10 3 10 2 10 –1 ... High speed fuses 6 BUSSMANN SERIES FULL LINE CATALOG 1007—July