Why Choose the Mersen X331151 US143N UltraSafe™ Fuse Holder?
The Mersen X331151, catalogue number US143N, is a premium 3-Pole + Neutral modular fuse holder from the UltraSafe™ US14 series. Designed for industrial power distribution, machinery and semiconductor protection, it accepts standard 14 × 51 mm cylindrical fuse-links while providing dependable overcurrent protection in demanding electrical installations.
The US143N combines three fused phase poles with an integrated neutral conductor in a compact DIN rail-mounted assembly. Its finger-safe IP20 enclosure remains protected during fuse replacement, helping improve operator safety and simplify maintenance. The holder also supports optional microswitch accessories for remote fuse status indication where required.
Rated for up to 50 A, with voltage ratings of 800 V AC UL, 1000 V DC UL and 750 V AC/DC IEC, the X331151 is ideal for protecting industrial drives, UPS systems, power conversion equipment, switchboards and automation systems.
Key Advantages
- 3-Pole + Neutral UltraSafe™ modular fuse holder.
- Accepts standard 14 × 51 mm cylindrical fuse-links.
- 50 A current rating.
- 800 V AC UL / 1000 V DC UL ratings.
- 750 V AC/DC IEC operation.
- Finger-safe IP20 protection.
- Compatible with optional microswitch accessories.
- DIN rail mounting for quick installation.
Key Features
- Mersen UltraSafe™ US14 series.
- Catalogue number: US143N.
- Item number: X331151.
- 3-Pole + Neutral configuration.
- 14 × 51 mm fuse compatibility.
- 50 A maximum fuse rating.
- 800 V AC UL / 1000 V DC UL.
- 750 V AC/DC IEC rating.
- Pressure plate terminals.
- IP20 finger-safe enclosure.
- DIN rail mounting to EN 60715.
- Field assembly compatible using optional pin-tie kits.
Reliable Protection for Three-Phase Distribution Systems
The UltraSafe™ US14 range provides secure housing for cylindrical fuse-links while maintaining finger-safe protection throughout installation and maintenance. The 3-Pole + Neutral arrangement enables three-phase circuits to be protected while providing a dedicated neutral conductor within the same modular assembly.
The X331151 is particularly well suited to industrial machinery, UPS systems, variable speed drives and power conversion equipment where compact, dependable fuse protection is required. Optional microswitch accessories can be added for remote fuse monitoring when required by the application.
Typical Applications
- Industrial control panels.
- Three-phase power distribution systems.
- Motor drives and variable speed drives.
- UPS systems.
- Power conversion equipment.
- OEM machinery.
- Automation systems.
- Switchboards and electrical enclosures.
