Class J Fuses

Mersen’s Class J fuses are high-performance, current-limiting fuses designed for robust circuit protection in industrial and commercial applications. These fuses comply with UL/CSA 248-14 Class J standards, offering fast-acting protection with high interrupting ratings (up to 300kA).
Key Series:
HSJ – Standard Class J fuses with a broad amperage range (0–600A), ideal for motor and transformer protection
Mersen’s Class J fuses are widely used in panel boards, control cabinets, and power distribution systems, providing reliable, code-compliant protection.
AJT – Time-delay variants for inrush current tolerance, suited for inductive loads like motors and HVAC systems.
A4J – Compact, space-saving fuses with the same performance as HSJ but in a smaller footprint.