Form No.
Page 1 of 2
BIF Doc #720032
Bussmann®
®
Square Body – US Style
1250V/1300V (IEC/U.L.) 50-1400A
Electrical Characteristics Ordering Information Curves
-FKE/115
Rated I2t (A2S) -FU/115 Type K Carton
Current Clearing Clearing Watts Visual Indicator Carton Weight
Size RMS-Amps Pre-arc at 1000V at 1250V Loss Indicator for Micro Qty. (kg) BIF #
50 135 815 1100 15 170M3688 170M3738
63 215 1300 1750 20 170M3689 170M3739
80 420 2500 3350 25 170M3690 170M3740
100 750 4450 5950 30 170M3691 170M3741
125 1450 9000 11500 35 170M3692 170M3742 17056630
1* 160 2600 16000 21000 40 170M3693 170M3743 1 0.425
200 5150 31000 41000 45 170M3694 170M3744
250 9200 54500 73000 55 170M3695 170M3745
315 18500 115000 150000 60 170M3696 170M3746
350 27000 165000 220000 65 170M3697 170M3747
160 1900 11500 15500 45 170M4688 170M4738
200 3800 22500 30000 50 170M4689 170M4739
250 7750 46000 61500 60 170M4690 170M4740
315 15000 90000 120000 65 170M4691 170M4741
1 350 20000 125000 165000 70 170M4692 170M4742
400 29500 175000 235000 75 170M4693 170M4743 1 0.675 17056632
450 42000 250000 335000 80 170M4694 170M4744
†500 69500 340000 85 170M4695 170M4745
†550 95000 465000 95 170M4696 170M4746
‡630 130000 660000 100 170M4697 170M4747
250 6500 38500 51500 65 170M5688 170M5738
280 9350 55500 74500 70 170M5689 170M5739
315 13000 77500 105000 75 170M5690 170M5740
350 16500 97500 135000 80 170M5691 170M5741
400 23000 140000 180000 85 170M5692 170M5742
450 34000 205000 270000 90 170M5693 170M5743
2 500 48000 285000 380000 95 170M5694 170M5744 1 0.740 17056634
550 62000 370000 495000 100 170M5695 170M5745
630 115000 575000 730000 110 170M5696 170M5746
†700 160000 795000 115 170M5697 170M5747
†800 245000 1200000 120 170M5698 170M5748
‡900 360000 1750000 125 170M5699 170M5749
‡1000 480000 2350000 135 170M5700 170M5750
315 9500 58000 77500 185 170M6688 170M6738
350 13500 81500 110000 90 170M6689 170M6739
400 19500 120000 160000 95 170M6690 170M6740
450 31000 185000 245000 100 170M6691 170M6741
500 39000 235000 310000 105 170M6692 170M6742
550 55000 325000 435000 110 170M6693 170M6743
630 83500 495000 665000 115 170M6694 170M6744
3700 115000 705000 940000 120 170M6695 170M6745 1 1.250 17056636
800 205000 995000 1300000 125 170M6696 170M6746
900 305000 1500000 1900000 130 170M6697 170M6747
¥1000 450000 2150000 135 †170M6698 †170M6748
¥1100 575000 2800000 140 †170M6699 †170M6749
¥1250 810000 3950000 145 ‡170M6700 ‡170M6750
¥1400 1250000 6000000 150 ‡170M6701 ‡170M6751
¥ U.L. Recognition at 1000V. 1 kg = 2.2 lbs. 1 lb = 0.45 kg
nInterrupting rating 100kA RMS Symmetrical.
nWatts loss provided at rated current.
nRated voltage (IEC) †1100 ‡1000V (Consult Bussmann for U.L. Recognition/ CSA Component Acceptance status.)
nMicroswitch indicator ordered separately.
7-11-01 SB01191
R
Form No.
Page 2 of 2
BIF Doc #720032
Bussmann®
This bulletin is intended to clearly present comprehensive product data and provide technical information that will help the end user with design applications. Bussmann reserves the right,
without notice, to change design or construction of any products and to discontinue or limit distribution of any products. Bussmann also reserves the right to change or update, without
notice, any technical information contained in this bulletin. Once a product has been selected, it should be tested by the user in all possible applications.
Square Body – US Style
1250V/1300V (IEC/U.L.) 50-1400A
Total Clearing I2t
The total clearing I2t at rated voltage and
at power factor of 15% are given in the
electrical characteristics. For other volt-
ages, the clearing I2t is found by multi-
plying by correction factor, K, given as
a function of applied working voltage,
Eg, (RMS).
Arc Voltage
This curve gives the peak arc voltage,
UL, which may appear across the fuse
during its operation as a function of the
applied working voltage, Eg, (RMS) at a
power factor of 15%.
Power Losses
Watts loss at rated current is given in
the electrical characteristics. The curve
allows the calculation of the power
losses at load currents lower than the
rated current. The correction factor, Kp,
is given as a function of the RMS load
current, Ib, in % of the rated current .
Electrical Characteristics
B
C2
DE
E
6
H I
C1
74
Size B C1 C2 D E H I
1* 156 130 101 59 45 20 10
1 160 127 102 69 53 25 14
2 160 127 102 77 61 25 14
3 159 128 101 92 76 36 16
Dimension in mm.
1mm = 0.0394∑ 1∑ = 25.4mm
Dimensions
US Style: Type -FU/115, -FKE/115
K
1.5
1.0
1.25
0.5
0.4
0.3
0.2
400 600 800 1000 1200 1400
Eg
UL
3
2.5
8
103
1.4
1.8
6
4
5
3400 600 800 1000 1200 1400
Eg
Kp
30 40 50 60 70 80 90 100%
Ib
1.0
0.8
0.4
0.5
0.6
0.3
0.2
0.1
- - - - - -
Dashed lines apply to the following amperages:
Size 1* 1 2 3
Amp 400 500-630 630-1000 800-1400
®
R
7-11-01 SB01191