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 10A CLASS J FUSE

A4J10
Mersen
1: HK$836.47
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

HK$836.47

HK$591.59

HK$545.56

HK$545.48

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 100A CLASS J FUSE

A4J100
Mersen
1: HK$1,659.29
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

HK$1,659.29

HK$1,476.72

HK$1,388.93

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 40A CLASS J FUSE

A4J40
Mersen
1: HK$1,327.78
20In Stock

Mfr. Part No.
A4J40

Mouser Part No
737-A4J40

Mersen

Industrial & Electrical Fuses 600V 40A CLASS J FUSE

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Datasheet

20In Stock

HK$1,327.78

HK$1,098.93

HK$1,012.21

HK$898.04

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 80A CLASS J FUSE

A4J80
Mersen
1: HK$2,172.46
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

HK$2,172.46

HK$1,798.54

HK$1,668.25

HK$1,554.07

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 125A CLASS J FUSE

A4J125
Mersen
1: HK$3,850.33
2In Stock

Mfr. Part No.
A4J125

Mouser Part No
737-A4J125

Mersen

Industrial & Electrical Fuses 600V 125A CLASS J FUSE

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Datasheet

2In Stock

HK$3,850.33

HK$2,853.82

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: HK$3,644.75
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

HK$3,644.75

HK$3,017.81

HK$2,791.76

Quote

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 175A CLASS J FUSE

A4J175
Mersen
1: HK$3,850.33
1In Stock

Mfr. Part No.
A4J175

Mouser Part No
737-A4J175

Mersen

Industrial & Electrical Fuses 600V 175A CLASS J FUSE

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Datasheet

1In Stock

HK$3,850.33

HK$2,853.82

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

Industrial & Electrical Fuses 600V 20A CLASS J FUSE

A4J20
Mersen
1: HK$844.85
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

HK$844.85

HK$698.78

HK$643.38

HK$551.07

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: HK$810.08
16In Stock

Mfr. Part No.
A4J30

Mouser Part No
737-A4J30

Mersen

Industrial & Electrical Fuses 600V 30A CLASS J FUSE

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Datasheet

16In Stock

HK$810.08

HK$795.78

HK$508.08

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: HK$1,121.04
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

HK$1,121.04

HK$1,061.12

HK$977.03

HK$830.22

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: HK$2,161.86
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

HK$2,161.86

HK$2,161.78

HK$1,463.82

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 200A CLASS J FUSE

A4J200
Mersen
1: HK$2,778.03
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

HK$2,778.03

HK$2,643.80

HK$2,372.87

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: HK$937.74
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

HK$937.74

HK$846.99

HK$846.91

HK$619.62

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: HK$1,234.07
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

HK$1,234.07

HK$1,142.50

HK$898.04

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 15A CLASS J FUSE

A4J15
Mersen
1: HK$753.12
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

HK$753.12

HK$671.74

HK$671.66

HK$545.48

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 25A CLASS J FUSE

A4J25
Mersen
1: HK$957.71
16Expected 21/9/2026

Mfr. Part No.
A4J25

Mouser Part No
737-A4J25

Mersen

Industrial & Electrical Fuses 600V 25A CLASS J FUSE

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Datasheet

16Expected 21/9/2026

HK$957.71

HK$792.41

HK$729.69

HK$625.38

Min.: 1
Mult.: 1

Semiconductor Fuses

25 A

600 VAC

Fast-Acting Fuses

300 VDC

200 kA

Clip

Class aR Fuses

Without Indicator

Box

A4J Class J Power Fuses

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