Mersen P331144 UltraSafe US143I modular fuse holder for 14×51 mm cylindrical fuse links with 3-pole configuration, visual blown fuse indicator, 50 A rating and IP20 finger-safe protection.
£89.27
The Mersen P331144, catalogue reference US143I, is a premium UltraSafe™ modular fuse holder designed for 14×51 mm cylindrical fuse links. Its 3-pole configuration and integrated visual blown fuse indicator provide dependable overcurrent protection whilst enabling rapid local identification of an operated fuse in industrial electrical systems.
Part of the trusted Mersen UltraSafe™ US14 series, the US143I features a robust thermoplastic construction with IP20 finger-safe protection, including during fuse replacement. The modular design allows quick DIN rail installation and can be field assembled with compatible accessories to create multi-pole arrangements where required.
Rated at 50 A with voltage ratings up to 800 V AC UL, 750 V AC IEC and 1000 V DC UL, the P331144 is ideal for industrial control panels, OEM machinery, motor control centres and electrical distribution equipment requiring reliable circuit protection and clear fuse indication.
The Mersen P331144 combines dependable overcurrent protection with an integrated visual indication system that enables maintenance personnel to quickly identify an operated fuse without removing the fuse holder. This helps reduce downtime and simplifies troubleshooting in industrial installations.
Its UltraSafe™ finger-safe construction, compact modular format and robust pressure-plate terminals make it an excellent solution for machinery, automation systems and electrical distribution equipment where reliability and safety are essential. Optional auxiliary microswitches are available separately for applications requiring remote fuse-status indication.
| Phase | Three Phase |
|---|---|
| Manufacturer | Mersen |
| Series | UltraSafe™ US14 |
| Model | US143I |
| Manufacturer part number | P331144 |
| EAN / UPC | 0782001311131 |
| Product type | Modular fuse holder |
| Fuse size | 14 × 51 mm cylindrical fuse links |
| Number of poles | 3 |
| Rated current | 50 A |
| Rated voltage AC (UL) | 800 V |
| Rated voltage AC (IEC) | 750 V |
| Rated voltage DC (UL) | 1000 V |
| Frequency | 50 / 60 Hz |
| Fuse indication | Visual blown fuse indicator |
| Terminal type | Pressure plate |
| Protection rating | IP20 |
| Mounting type | DIN rail mounting |
| Approximate weight | 0.44 kg |
| HS Code | 85361050 |
| Country of Manufacture | Tunisia |
The P331144 is a three-pole modular fuse holder designed to protect industrial AC and DC electrical circuits using 14×51 mm cylindrical fuse links.
It is designed specifically for 14×51 mm cylindrical fuse links.
Yes. It incorporates an integrated visual blown fuse indicator for rapid local identification of an operated fuse.
Yes. The UltraSafe™ US14 range supports compatible auxiliary microswitch accessories that can be fitted separately where remote fuse-status signalling is required.
The P331144 is rated for 50 A and supports systems up to 800 V AC UL, 750 V AC IEC and 1000 V DC UL.
Mersen UltraSafe™ fuse holders are trusted by panel builders, OEMs and industrial engineers for delivering dependable circuit protection, finger-safe operation and reliable performance across demanding industrial installations.
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LED Controls is a specialist distributor of factory automation and industrial controls, supplying OEMs, machine builders, panel builders and end users throughout the UK and worldwide. As a trusted UK distributor for many of the world’s leading automation manufacturers, we provide industrial control products, technical expertise and bespoke automation solutions backed by outstanding customer service.
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...