Bussmann
®
FWX 250V
Type
Rated
Current
RMS-Amps
35-2500A
Ordering Information
Watts
Loss
Part
Number
Carton
Qty.
Carton
Weight
(lbs)
Dimensions
Figure
Number
†
®
Electrical Characteristics
I
2
t (A
2
Sec)
Clearing
Pre-arc
at 250V
Curves
BIF #
35
50
230
4.2
FWX-35A
_____________________________________________________________________________________
_
40
60
310
5.2
FWX-40A
____________________________________________________________________________________
__
45
80
390
5.7
FWX-45A
____________________________________________________________________________________
__
50
100
520
6.0
FWX-50A
____________________________________________________________________________________
__
60
140
740
8.1
FWX-60A
____________________________________________________________________________________________________________
_
70
330
1400
7.2
FWX-70A
____________________________________________________________________________________
__
80
430
1850
8.1
FWX-80A
____________________________________________________________________________________
__
90
570
2450
9.0
FWX-90A
____________________________________________________________________________________
__
100
740
3150
10.0
FWX-100A
____________________________________________________________________________________
__
125
1130
4850
12.5
FWX-125A
____________________________________________________________________________________
__
150
1620
6950
15.7
FWX-150A
____________________________________________________________________________________
__
175
2170
9300
18.5
FWX-175A
____________________________________________________________________________________
__
200
2790
12000
22
FWX-200A
_____________________________________________________________________________________
_
225
3210
14700
24
FWX-225A
____________________________________________________________________________________
__
250
3960
18100
27
FWX-250A
FWX
____________________________________________________________________________________
__
250V
275
4720
21600
31
FWX-275A
____________________________________________________________________________________
__
300
6000
27300
32
FWX-300A
____________________________________________________________________________________
__
350
10600
48600
39
FWX-350A
____________________________________________________________________________________
__
400
14500
66100
44
FWX-400A
____________________________________________________________________________________
__
450
22100
101000
49
FWX-450A
____________________________________________________________________________________
__
500
28000
128000
54
FWX-500A
____________________________________________________________________________________
__
600
41100
188000
62
FWX-600A
____________________________________________________________________________________
__
700
48800
190000
72
FWX-700A
____________________________________________________________________________________
__
800
59000
230000
84
FWX-800A
____________________________________________________________________________________ _
_
1000
44000
360000
100
FWX-1000AH
__
____________________________________________________________________________________
1200
92000
750000
103
FWX-1200AH
___
___________________________________________________________________________________
1500
120000
880000
140
FWX-1500AH
___
___________________________________________________________________________________
1600
160000
1200000
140
FWX-1600AH
___
___________________________________________________________________________________
2000
320000
2300000
151
FWX-2000AH
___
___________________________________________________________________________________
2500
670000
4700000
163
FWX-2500AH
1 kg = 2.2 lbs
1 lb = 0.45 kg
5
1.40
0.32
359
Fig. 1
_______ ___
___ _
1
0.52
___
__________
_
0.90
Fig. 2
_____________
2.86
Fig. 3
35785299
† U.L. Recognition on 35 through 800 amperes only.
Interrupting rating 200kA RMS Symmetrical.
Watts loss provided at rated current.
(250 Vdc/Interrupting rating 20kA) U.L. Recognition on 35 through 800 amperes only.
7-11-01
SB01191
Form No. FWX 250
Page 1 of 2
BIF Doc #720005
Bussmann
®
FWX 250V
35-2500A
Arc Voltage
This curve gives the peak arc voltage,
U
L
, which may appear across the fuse
during its operation as a function of the
applied working voltage, E
g
, (RMS) at a
power factor of 15%.
†
®
Electrical Characteristics
Total Clearing I
2
t
The total clearing I
2
t at rated voltage and
at power factor of 15% are given in the
electrical characteristics. For other volt-
ages, the clearing I
2
t is found by multi-
plying by correction factor, K, given as
a function of applied working voltage,
E
g
, (RMS).
1.5
K
1.0
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, K
p
,
is given as a function of the RMS load
current, I
b
, in % of the rated current .
1.0
K
p
0.8
0.6
0.5
0.4
0.3
1.4
1.2
10
3
800
U
L
0.5
0.3
0.2
0.15
1)
2)
600
500
400
300
E
g
200
50
100
150
200
1) 35-800 Amp Range
2) 1000-2500 Amp Range
1)
2)
E
g
250
0.2
0.1
30 40 50
60
70
I
b
80 90 100%
75
125
200
250
300
1) 35-800 Amp Range
2) 1000-2500 Amp Range
Dimensions
Fig. 1: 35-800 Amp Range
J
Fig. 2: 1000-1200 Amp Range
Fig. 3: 1500-2500 Amp Range
A
A D E C
A
D
B
F
G
C
B
C
H
B
Order #
FWX-35A-60A
FWX-70A-200A
FWX-225A-600A
FWX-700A-800A
FWX-1000AH-1200AH
FWX-1500AH-2500AH
Fig.
1
1
1
1
2
3
A
3.19
3.13
3.84
3.84
2.59
2.59
B
0.81
1.22
1.50
2.00
3.00
3.50
C
1.59
1.59
1.59
1.59
1.50
1.50
D
2.59
2.44
2.94
3.03
—
1.50
E
2.25
2.19
2.25
2.28
—
—
F
0.34
0.34
0.41
0.41
—
—
G
0.63
1.00
1.00
1.50
—
—
H
0.13
0.19
0.25
0.25
—
—
J
0.52
0.47
0.75
0.78
—
—
Thread Depth
—
—
—
—
Tapped ‹Ω•∑-24 ≈ ⁄Ω™∑
Tapped ‹Ω•∑-24 ≈ ⁄Ω™∑
Dimension in inches.
1mm = 0.0394∑
1∑ = 25.4mm
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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
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7-11-01
SB01191
Form No.FWX 250
Page 2 of 2
BIF Doc #720005