Why Choose the Mersen HSJ175 High-Speed Class J Fuse?
The Mersen HSJ175 is a 175 A High-Speed Class J fuse engineered to provide both branch-circuit protection and rapid semiconductor protection in demanding industrial applications. Part of the Mersen Amp-Trap® HSJ series, it combines the low I²t characteristics of a semiconductor fuse with the UL Listed performance of a Class J branch-circuit fuse, making it ideal for protecting modern power-electronic equipment.
Designed for industrial automation and power conversion systems, the HSJ175 delivers rapid fault interruption while withstanding the elevated inrush currents associated with electronic motor controllers and variable frequency drives. Its current-limiting design helps minimise thermal stress, reducing equipment damage and improving system reliability.
Rated at 175 A, 600 V AC / 500 V DC, the HSJ175 is suitable for protecting drives, soft starters, UPS systems, rectifiers, inverters, SCRs, diodes and other semiconductor-based equipment.
Key Advantages
- High-speed Class J fuse for branch-circuit and semiconductor protection.
- 175 A rated current for industrial power applications.
- 600 V AC / 500 V DC rated voltage.
- Very low I²t limits thermal energy during fault conditions.
- Excellent cycling capability for repeated motor starts and stops.
- 200 kA AC interrupting rating for high fault-current applications.
Key Features
- Mersen Amp-Trap® HSJ series.
- 175 A current rating.
- 600 V AC / 500 V DC voltage rating.
- High-speed semiconductor protection.
- Class J blade fuse construction.
- Current-limiting operation with low let-through energy.
- Optimised overload capability for electronic motor-controller starting.
- Suitable for compatible Class J fuse holders.
High-Speed Protection for Modern Industrial Power Systems
The Mersen HSJ175 is designed to protect both branch circuits and sensitive semiconductor devices using a single UL Listed Class J fuse. Its low I²t characteristic enables rapid fault clearing before excessive thermal energy can damage SCRs, GTOs, IGBTs, diodes, solid-state relays and other power semiconductors.
Its optimised overload capability also allows it to withstand the temporary inrush currents encountered during electronic motor-controller starting while maintaining excellent current-limiting performance during severe fault conditions.
Typical Applications
- Variable frequency drives (VFDs).
- Electronic motor controllers.
- Soft starters.
- Power converters and rectifiers.
- UPS systems.
- Industrial control panels.
- Solid-state relays.
- Phase controllers.
