1
Axial Lead & Cartridge Fuses
3AG > Fast Acting > 312/318 Series
312/318 Series
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/312.html
or /318.html for current information.
312/318 Series
312/318 Series Lead-Free 3AG, Fast-Acting Fuse
The 3AG Fast-Acting Fuse solves a broad range
of application requirements while offering reliable
performance and cost-effective circuit protection.
Agency Approvals
Agency Agency File Number Ampere Range
E10480
AU1410
312 Series: 62mA - 10A
318 Series: 62mA - 10A
312 Series: 12A - 30A
LR 29862 312 Series: 62mA - 30A
318 Series: 62mA - 10A
PS
E
NBK040205-
E10480B/F 312/318 Series: 1A - 10A
E10480 318 Series: 12A - 30A
SU05001-
5005/5006/6005/6008
312/318 Series:
1A/ 1.25A / 1.6A/
2A - 10A
312 Series: 62mA - 10A
318 Series: 62mA - 10A
Features
Electrical Characteristics for Series
Applications
% of Ampere
Rating Ampere Rating Opening Time
100% 62mA – 35A 4 hours, Minimum
135% 62mA – 35A 1 hour, Maximum
200%
10mA – 10A 5 sec., Maximum
12A – 30A 10 sec., Maximum
35A 20 sec., Maximum
UÊ Ê>VVÀ`>ViÊÜÌÊ1Ê
Standard 248-14
UÊ Û>>LiÊÊV>ÀÌÀ`}iÊ
and axial lead format
and with various
forming dimensions
UÊ ,-ÊV«>ÌÊ>`ÊÊÊ
Lead-free
Used as supplementary protection in appliance or
utilization equipment to provide individual protection for
components or internal circuits.
PS
E
Description
Revised: February 15, 2012
Introduction to Circuit Protection
Introduction to Circuit Protection
Transientology
2
Axial Lead & Cartridge Fuses
3AG > Fast Acting > 312/318 Series
312/318 Series © 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/312.html
or /318.html for current information.
Amp
Code
Ampere
Rating (A)
Voltage
Rating
(V)
Interrupting
Rating
Nominal
Cold
Resistance
(Ohms)
Nominal
Melting
I2t (A2 sec)
Agency Approvals
PS
E
.062 0.062 250
35A@250Vac
10KA@125Vac
24.7000 0.000249 x x x
.100 0.1 250 11.2800 0.00102 x x x
.125 0.125 250 7.1450 0.00289 x x x
.150 0.15 250 5.1300 0.00550 x x x
.175 0.175 250 3.8750 0.00960 x x x
.187 0.187 250 3.4200 0.0128 x x x
.200 0.2 250 3.0200 0.0165 x x x
.250 0.25 250 2.0100 0.0355 x x x
.300 0.3 250 1.4050 0.0689 x x x
.375 0.375 250 0.8250 0.185 x x x
.500 0.5 250 0.4980 0.483 x x x
.600 .6 250 0.3620 0.880 x x x
.750 0.75 250 0.2445 1.84 x x x
001. 1 250 0.1900 0.760 x xxxx
1.25 1.25 250
100A@250Vac
10KA@125Vac
0.1385 1.45 x xxxx
01.5 1.5 250 0.1036 2.35 x x x x
01.6 1.6 250 0.0934 2.80 x xxxx
1.75 1.75 250 0.0856 3.60 x x x x
01.8 1.8 250 0.0825 3.85 x x x x
002. 2 250 0.0704 5.20 x xxxx
2.25 2.25 250 0.0594 7.20 x xxxx
02.5 2.5 250 0.0513 9.54 x xxxx
003. 3 250 0.0427 14.0 x xxxx
004. 4 250
200A@250Vac
10KA@125Vac
0.0293 28.5 x xxxx
005. 5 250 0.0224 50.0 x xxxx
006. 6 250 0.0178 118.0 x xxxx
007. 7 250 0.0146 118.0 x xxxx
008. 8 250 0.0122 166.0 x xxxx
010. 10 250 0.0093 298.0 x xxxx
012.*12 32
300A@32 Vac
0.0072 234.6 x x** x
015.*15 32 0.0052 490.5 x x** x
020.*20 32 0.0035 1029 x x** x
025.*25 32 0.0024 2041 x x** x
030.*30 32 0.0019 3717 x x** x
035. 35 32 0.0013 7531
NOTES:
** For 318 Series 12A to 30A, the agency approval is only cURus.
Electrical Characteristic Specifications by Item
3
Axial Lead & Cartridge Fuses
3AG > Fast Acting > 312/318 Series
312/318 Series
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/312.html
or /318.html for current information.
312/318 Series
Average Time Current Curves
1000
10 0
10
1
0.1
0.01
110 10 0
0.01 0.1
.062 A
.125 A
.250 A
.375 A
.500 A
.750 A
1 A
1.5 A
2 A
2.5 A
3 A
4 A
5 A
6 A
7 A
8 A
10 A
0.005
TIME IN SECONDS
CURRENT IN AMPERES
Temperature Rerating Curve
Soldering Parameters - Wave Soldering
Dwell Time
0
20
40
60
80
100
120
140
160
180
200
220
240
260
280
300
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
Time (Seconds)
Temperature (°C) - Measured on bottom side of board
Cooling Time
Preheat Time
Wave Parameter Lead-Free Recommendation
Preheat:
(Depends on Flux Activation Temperature) /Þ«V>Ê`ÕÃÌÀÞÊ,iVi`>Ì®
Temperature Minimum: 100° C
Temperature Maximum: 150° C
Preheat Time: 60-180 seconds
Solder Pot Temperature: 260° C Maximum
Solder Dwell Time: 2-5 seconds
Recommended Hand-Solder Parameters:
-`iÀÊÀÊ/i«iÀ>ÌÕÀi\ÊÊÎxäcÊʳÉÊxc
i>Ì}Ê/i\ÊÊxÊÃiV`ÃÊ>Ý°
Note: These devices are not recommended for IR or
Convection Reflow process.
Recommended Process Parameters:
Please contact Littelfuse for more details on those T-C Curves of other
ampere ratings which are not published.
Introduction to Circuit Protection
Introduction to Circuit Protection
Transientology
4
Axial Lead & Cartridge Fuses
3AG > Fast Acting > 312/318 Series
312/318 Series © 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/312.html
or /318.html for current information.
Product Characteristics
Dimensions
Packaging
Materials
Body: Glass
Cap: Nickel–plated brass
Leads: Tin–plated Copper
Terminal Strength -/ÓäÓ]ÊiÌ`ÊÓ££]ÊÊ
Test Condition A
Solderability ,iviÀiViÊÊÈä£ÓÇÊ-iV`Ê`ÌÊ
2003-01 Annex A
Product Marking
Cap1: Brand logo, current and voltage
ratings
Cap2: Series and agency approval
marks
Operating
Temperature qxx¨ÊÌʳ£Óx¨
Thermal
Shock
-/ÓäÓ]ÊiÌ`Ê£äÇ]ÊÊ/iÃÌÊ`ÌÊ
\ÊxÊVÞViÃÊÈxcÊÌʳ£Óxc®
Vibration -/ÓäÓ]ÊiÌ`ÊÓä£Ê
Humidity
-/ÓäÓ]ÊiÌ`Ê£äÎ]ÊÊ
/iÃÌÊ`ÌÊ\Ê}Ê,Êx¯®]Ê
and Elevated temperature (40°C) for 240 hours
Salt Spray -/ÓäÓ]ÊiÌ`Ê£ä£]ÊÊ
Test Condition B
Part Numbering System
0312 M X Pxxxx
Lead-free
Packaging Code
Quantity Code
Amp Code
Series
X = Filler
M = 1000
Refer to Amp Code column of
Electrical Characteristics Table
Measurements displayed in millimeters (inches)
Packaging Option Packaging Specification Quantity Quantity &
Packaging Code Taping Width
312 Series
Bulk N/A 1000 MX N/A
Bulk N/A 100 8 N/A
318 Series
Bulk N/A 1000 MX N/A
Bulk N/A 100 8 N/A
Bulk N/A 1000 MXB N/A
312 Series
318 Series
6.35
(.25")
32.72
(1.288")
31.75
(1.25")
6.985
(.275")
0.813 (.032") (0.062-15A)
1.016 (.040") (20-35A)
39.68
(1.56") TYP.
Standard Length
12.70
(0.50”) TYP
Short Lead Option
Axial Lead Material:
Tin Coated Copper