Industrial & Electrical Fuses

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A4J Class J Power Fuses

Mersen A4J Class J Power Fuses provide excellent current-limiting protection to numerous applications. These fuses have unique dimensions that prevent the substitution of other fuses with lower ratings, interrupting ratings, or current-liming capability, providing additional protection against mismating. Constructed with a fiberglass body, dimensional stability is provided in harsh industrial environments, and the easy-to-read imprint label allows for quick recognition and replacement. Mersen A4J Class J Power Fuses are suitable for capacitors, load centers, switchboards, circuit breakers, feeder circuits, and panelboards.

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Part #

Industrial & Electrical Fuses 600V 100A CLASS J FUSE

A4J100
Mersen
1: $182.42
54In Stock

Mfr. Part No.
A4J100

Mouser Part No
737-A4J100

Mersen

Industrial & Electrical Fuses 600V 100A CLASS J FUSE

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Datasheet

54In Stock

$182.42

$151.29

$139.48

$115.36

$106.19

Min.: 1
Mult.: 1

Semiconductor Fuses

100 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Knife Blade

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 10A CLASS J FUSE

A4J10
Mersen
1: $85.29
20In Stock

Mfr. Part No.
A4J10

Mouser Part No
737-A4J10

Mersen

Industrial & Electrical Fuses 600V 10A CLASS J FUSE

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Datasheet

20In Stock

$85.29

$70.75

$65.25

$54.02

View

Min.: 1
Mult.: 1

Semiconductor Fuses

10 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Clip

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 125A CLASS J FUSE

A4J125
Mersen
1: $387.74
3In Stock

Mfr. Part No.
A4J125

Mouser Part No
737-A4J125

Mersen

Industrial & Electrical Fuses 600V 125A CLASS J FUSE

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Datasheet

3In Stock

$387.74

$321.37

$296.25

$244.76

Min.: 1
Mult.: 1

Semiconductor Fuses

125 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Knife Blade

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 150A CLASS J FUSE

A4J150
Mersen
1: $366.62
2In Stock

Mfr. Part No.
A4J150

Mouser Part No
737-A4J150

Mersen

Industrial & Electrical Fuses 600V 150A CLASS J FUSE

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Datasheet

2In Stock

$366.62

$303.86

$280.12

$231.43

Min.: 1
Mult.: 1

Semiconductor Fuses

150 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Knife Blade

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 20A CLASS J FUSE

A4J20
Mersen
1: $86.16
17In Stock

Mfr. Part No.
A4J20

Mouser Part No
737-A4J20

Mersen

Industrial & Electrical Fuses 600V 20A CLASS J FUSE

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Datasheet

17In Stock

$86.16

$71.47

$65.92

$54.56

View

Min.: 1
Mult.: 1

Semiconductor Fuses

20 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Clip

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 30A CLASS J FUSE

A4J30
Mersen
1: $79.45
13In Stock

Mfr. Part No.
A4J30

Mouser Part No
737-A4J30

Mersen

Industrial & Electrical Fuses 600V 30A CLASS J FUSE

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Datasheet

13In Stock

$79.45

$65.91

$60.79

$50.32

View

Min.: 1
Mult.: 1

Semiconductor Fuses

30 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Clip

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 60A CLASS J FUSE

A4J60
Mersen
1: $125.77
7In Stock

Mfr. Part No.
A4J60

Mouser Part No
737-A4J60

Mersen

Industrial & Electrical Fuses 600V 60A CLASS J FUSE

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Datasheet

7In Stock

$125.77

$104.33

$96.21

$79.61

$73.32

Min.: 1
Mult.: 1

Semiconductor Fuses

60 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Clip

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 70A CLASS J FUSE

A4J70
Mersen
1: $211.77
6In Stock

Mfr. Part No.
A4J70

Mouser Part No
737-A4J70

Mersen

Industrial & Electrical Fuses 600V 70A CLASS J FUSE

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Datasheet

6In Stock

$211.77

$175.62

$161.92

$133.92

$123.27

Min.: 1
Mult.: 1

Current Limiting Fuses

70 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Knife Blade

Class J Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 80A CLASS J FUSE

A4J80
Mersen
1: $224.79
15In Stock

Mfr. Part No.
A4J80

Mouser Part No
737-A4J80

Mersen

Industrial & Electrical Fuses 600V 80A CLASS J FUSE

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Datasheet

15In Stock

$224.79

$186.43

$171.89

$142.16

$130.86

Min.: 1
Mult.: 1

Current Limiting Fuses

80 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Knife Blade

Class T Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 200A CLASS J FUSE

A4J200
Mersen
1: $329.75
3In Stock

Mfr. Part No.
A4J200

Mouser Part No
737-A4J200

Mersen

Industrial & Electrical Fuses 600V 200A CLASS J FUSE

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Datasheet

3In Stock

$329.75

$273.36

$252.01

$208.31

Min.: 1
Mult.: 1

Semiconductor Fuses

200 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Knife Blade

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 3A CLASS J FUSE

A4J3
Mersen
1: $96.89
10In Stock

Mfr. Part No.
A4J3

Mouser Part No
737-A4J3

Mersen

Industrial & Electrical Fuses 600V 3A CLASS J FUSE

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Datasheet

10In Stock

$96.89

$80.36

$74.13

$61.38

View

Min.: 1
Mult.: 1

Semiconductor Fuses

3 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Clip

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 50A CLASS J FUSE

A4J50
Mersen
1: $136.03
4In Stock

Mfr. Part No.
A4J50

Mouser Part No
737-A4J50

Mersen

Industrial & Electrical Fuses 600V 50A CLASS J FUSE

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Datasheet

4In Stock

$136.03

$112.83

$104.05

$86.10

$79.30

Min.: 1
Mult.: 1

Current Limiting Fuses

50 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Clip

Class T Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 25A CLASS J FUSE

A4J25
Mersen
1: $160.83
16Expected 5/10/2026

Mfr. Part No.
A4J25

Mouser Part No
737-A4J25

Mersen

Industrial & Electrical Fuses 600V 25A CLASS J FUSE

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Datasheet

16Expected 5/10/2026

$160.83

$133.06

$122.54

$103.47

Min.: 1
Mult.: 1

Semiconductor Fuses

25 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Clip

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 40A CLASS J FUSE

A4J40
Mersen
1: $136.03
20Expected 27/10/2026

Mfr. Part No.
A4J40

Mouser Part No
737-A4J40

Mersen

Industrial & Electrical Fuses 600V 40A CLASS J FUSE

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Datasheet

20Expected 27/10/2026

$136.03

$112.83

$104.05

$86.10

$79.30

Min.: 1
Mult.: 1

Semiconductor Fuses

40 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Clip

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 15A CLASS J FUSE

A4J15
Mersen
1: $85.29
Non-Stocked Lead-Time 8 Weeks

Mfr. Part No.
A4J15

Mouser Part No
737-A4J15

Mersen

Industrial & Electrical Fuses 600V 15A CLASS J FUSE

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Datasheet

Non-Stocked Lead-Time 8 Weeks

$85.29

$70.75

$65.25

$54.02

View

Min.: 1
Mult.: 1

Semiconductor Fuses

15 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Clip

Class aR Fuses

Without Indicator

Box

Industrial & Electrical Fuses 600V 175A CLASS J FUSE

A4J175
Mersen
1: $387.74
Non-Stocked Lead-Time 10 Weeks

Mfr. Part No.
A4J175

Mouser Part No
737-A4J175

Mersen

Industrial & Electrical Fuses 600V 175A CLASS J FUSE

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Datasheet

Non-Stocked Lead-Time 10 Weeks

$387.74

$321.37

$296.25

$244.76

Min.: 1
Mult.: 1

Semiconductor Fuses

175 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Knife Blade

Class aR Fuses

Without Indicator

Box

A4J Class J Power Fuses

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