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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Image	Part #	Mfr.	Description	Datasheet	Availability	Pricing (JPY) Filter the results in the table by unit price based on your quantity.	Qty.	Product	Current Rating	Voltage Rating AC	Fuse Type	Voltage Rating DC	Interrupt Rating	Termination Style	Class	Indicator Style	Packaging
Industrial & Electrical Fuses 600V 100A CLASS J FUSE A4J100 Mersen 1: ¥20,564.8 54In Stock	Mfr. Part # A4J100 Mouser Part # 737-A4J100	Mersen	Industrial & Electrical Fuses 600V 100A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	54In Stock	¥20,564.8 ¥17,053.5 ¥15,724.7 ¥13,005.6 ¥11,972.5	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: ¥10,416.1 20In Stock	Mfr. Part # A4J10 Mouser Part # 737-A4J10	Mersen	Industrial & Electrical Fuses 600V 10A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	20In Stock	¥10,416.1 ¥8,640.5 ¥7,969.5 ¥6,597.5 View ¥6,077.6 ¥5,446.4	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: ¥47,355.1 3In Stock	Mfr. Part # A4J125 Mouser Part # 737-A4J125	Mersen	Industrial & Electrical Fuses 600V 125A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	3In Stock	¥47,355.1 ¥36,399.2 ¥34,112 ¥30,432.8	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: ¥43,546.4 2In Stock	Mfr. Part # A4J150 Mouser Part # 737-A4J150	Mersen	Industrial & Electrical Fuses 600V 150A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	2In Stock	¥43,546.4 ¥36,095.2 ¥33,273.2 ¥27,489.6	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: ¥10,522.4 17In Stock	Mfr. Part # A4J20 Mouser Part # 737-A4J20	Mersen	Industrial & Electrical Fuses 600V 20A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	17In Stock	¥10,522.4 ¥8,728.6 ¥8,050.9 ¥6,663.9 View ¥6,139.1 ¥5,502.9	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 25A CLASS J FUSE A4J25 Mersen 1: ¥11,517.4 6In Stock 10Expected 10/5/2026	Mfr. Part # A4J25 Mouser Part # 737-A4J25	Mersen	Industrial & Electrical Fuses 600V 25A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	6In Stock 10Expected 10/5/2026	¥11,517.4 ¥9,554.1 ¥8,809.9 ¥7,293.5 View ¥6,717.1 ¥6,019.5	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 30A CLASS J FUSE A4J30 Mersen 1: ¥8,992.7 13In Stock	Mfr. Part # A4J30 Mouser Part # 737-A4J30	Mersen	Industrial & Electrical Fuses 600V 30A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	13In Stock	¥8,992.7 ¥7,461.2 ¥6,881.5 ¥5,697.2 View ¥5,247.1 ¥4,704	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: ¥14,058.7 7In Stock	Mfr. Part # A4J60 Mouser Part # 737-A4J60	Mersen	Industrial & Electrical Fuses 600V 60A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	7In Stock	¥14,058.7 ¥11,660.2 ¥10,753.3 ¥8,898 ¥8,193.7	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: ¥23,551.3 6In Stock	Mfr. Part # A4J70 Mouser Part # 737-A4J70	Mersen	Industrial & Electrical Fuses 600V 70A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	6In Stock	¥23,551.3 ¥19,528.4 ¥18,006.9 ¥14,889.2 ¥13,706.6	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: ¥27,454.7 8In Stock	Mfr. Part # A4J80 Mouser Part # 737-A4J80	Mersen	Industrial & Electrical Fuses 600V 80A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	8In Stock	¥27,454.7 ¥22,769 ¥20,993.4 ¥17,362.4 ¥15,982.1	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: ¥36,540.3 3In Stock	Mfr. Part # A4J200 Mouser Part # 737-A4J200	Mersen	Industrial & Electrical Fuses 600V 200A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	3In Stock	¥36,540.3 ¥30,295 ¥27,929.7 ¥23,079.6	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: ¥10,773.2 10In Stock	Mfr. Part # A4J3 Mouser Part # 737-A4J3	Mersen	Industrial & Electrical Fuses 600V 3A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	10In Stock	¥10,773.2 ¥8,937.8 ¥8,936.2 ¥7,795.1 View ¥7,511 ¥7,177.2 Quote	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: ¥15,100.2 4In Stock	Mfr. Part # A4J50 Mouser Part # 737-A4J50	Mersen	Industrial & Electrical Fuses 600V 50A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	4In Stock	¥15,100.2 ¥12,523.9 ¥11,548.9 ¥9,555.7 ¥8,800	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 40A CLASS J FUSE A4J40 Mersen 1: ¥15,100.2 10Expected 10/27/2026	Mfr. Part # A4J40 Mouser Part # 737-A4J40	Mersen	Industrial & Electrical Fuses 600V 40A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	10Expected 10/27/2026	¥15,100.2 ¥12,523.9 ¥11,548.9 ¥9,555.7 ¥8,800	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: ¥10,416.1 Non-Stocked Lead-Time 8 Weeks	Mfr. Part # A4J15 Mouser Part # 737-A4J15	Mersen	Industrial & Electrical Fuses 600V 15A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	Non-Stocked Lead-Time 8 Weeks	¥10,416.1 ¥8,640.5 ¥7,969.5 ¥6,597.5 View ¥6,077.6 ¥5,446.4	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: ¥47,355.1 Non-Stocked Lead-Time 10 Weeks	Mfr. Part # A4J175 Mouser Part # 737-A4J175	Mersen	Industrial & Electrical Fuses 600V 175A CLASS J FUSE Learn More about Mersen a4j power fuses	Datasheet	Non-Stocked Lead-Time 10 Weeks	¥47,355.1 ¥39,249.4 ¥36,181.6 ¥29,893	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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