The Mersen Amp-Trap® A4J30 is a 30-amp, Class J current-limiting fuse engineered for demanding electrical installations where speed and protection are non-negotiable. Rated for 600 V AC / 300 V DC with an exceptional 200/100 kA interrupting capacity, this fast-acting fuse is the go-to choice for professional electricians and contractors protecting motor controls, panelboards, and industrial equipment on the job site. Its rejection-style ferrule design ensures it can only be installed in Class J fuseholders, eliminating the risk of misapplication — a critical safeguard when working on live commercial or industrial systems. Whether you're protecting variable frequency drives, disconnects, or distribution equipment, the A4J30 delivers the reliable, code-compliant overcurrent protection your installations demand.

Specifications

Brand Mersen
Series Amp-Trap® A4J
MPN A4J30
Amperage Rating 30 A
Voltage Rating 600 V AC / 300 V DC
Interrupting Capacity 200 kA AC / 100 kA DC
Fuse Class Class J
Fuse Type Current Limiting, Fast Acting
Rejection Type Rejection (Class J Fuseholder Only)
Terminal Type Ferrule
Mounting Type Clip Mount
Body Style Cylindrical
Body Material Polyester
Body Dimensions 13/16 in Dia x 2-1/4 in L