Axial Lead & Cartridge Fuses
PICO® ll > Very Fast-Acting > 251/253 Series
Product Characteristics
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Materials
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Condition I (100 G’s peak for 6
msecs.)
Solderability
Lead Pull Force
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Shock
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Vibration
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QPL for MIL-PRF-23419. To order, change
251 to 253
FusesTo MIL SPEC
Moisture Resistance
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and up to 260ºC, maximum
Resistance to Soldering
Heat
Flammability Rating
UL 94V–0
Part Numbering System
Dimensions
251 Series (RoHS Version) Markings
(T1 lead length)
0251 xxxx N R T1 L
62.7 (2.468")
52.4 (2.062")*
27.78
27.78
(1.094")
Series
251 = Standard type
(1.094")
7.11 (.280")
F
1 A
L
253 = Military type
2.80
(.11")
MAX
5.0 (.197")
6.35 (.25")
tape
6.35 (.25")
tape
Current Rating
Refer to Amp Code column of
Electrical Specifications Table
F
1 A
L
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 12-15 amp
Quantity
251 Series (RoHS and Halogen-free Version) Markings
N = 5000
P = 2000
M = 1000
H = 100
(T1 lead length)
62.7 (2.468")
52.4 (2.062")*
27.78
(1.094")
27.78
(1.094")
7.11 (.280")
F
1 A
Type of Packaging
R = Reel
A = Ammo Pack
X = Loose Pack
L
2.80
(.11")
MAX
5.0 (.197")
6.35 (.25")
tape
6.35 (.25")
tape
F
1 A
L
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 12-15 amp
Lead Length
The default lead length for Ammo pack and
Loose pack is now T1 for 251 series, and
remains T3 for 253 series, therefore:
T1 = 52.4mm (2.062”), 251 series only*
Blank = 52.4mm (2.062”) for 251 series*
or 73mm (2.874”) for 253 series**
253 Series (RoHS Version) Markings
(T3 lead length)
83.31 (3.28")
73.0 (2.874")**
38.1
(1.5")
38.1
(1.5")
7.11 (.280")
F
1 A
L
2.61 (.103")
MAX
5.0 (.197")
6.35 (.25")
tape
6.35 (.25")
tape
Option Codes
L
= RoHS + HF
F
1 A
L
Wire Diameter:
0.64 (.025") for 0.62-10.0 amp,
0.81 (.032") for 15 amp
Packaging
Quantity &
Packaging Option
Packaging Specification
EIA 296
Packaging Code
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above in "Part Numbering System”
EIA 296
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/PUFTꢆꢀꢀꢀ
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© 2012 Littelfuse, Inc.
251/253 Series
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/251.html
or /253.html for current information.
LITTELFUSE [ LITTELFUSE ]
