Mersen S331147 US143MI UltraSafe three-pole modular fuse holder for 14 x 51 mm cylindrical fuse links, featuring visual indication, an integrated microswitch, pressure-plate terminals and IP20 protection.
£114.48
The Mersen S331147, catalogue reference US143MI, is a robust three-pole modular fuse holder designed for safe and dependable protection of industrial electrical circuits. As part of the Mersen UltraSafe™ US14 series, it accommodates standard 14 × 51 mm cylindrical fuse links and combines high voltage capability with a compact DIN rail mounting format.
This fuse holder incorporates a visual blown-fuse indicator and an integrated microswitch, enabling operators to identify fuse operation locally while also providing a signal for remote monitoring systems. These features help maintenance teams locate faults quickly, reduce diagnostic time and improve the operational availability of industrial equipment.
With a rated current of up to 50 A, UL voltage ratings of 800 V AC and 1000 V DC, pressure-plate terminals and IP20 finger-safe protection, the Mersen S331147 is suitable for control panels, power distribution equipment, photovoltaic systems and demanding industrial automation applications.
The Mersen S331147 securely houses three cylindrical fuse links and provides a convenient means of isolating and replacing fuses within industrial electrical systems. Its finger-safe construction reduces the risk of accidental contact with live components, including during normal fuse handling and maintenance procedures.
The combination of visual indication and an auxiliary microswitch supports both local inspection and integration with alarms, PLC inputs or supervisory systems. This allows fuse operation to be detected quickly, helping minimise production interruptions and simplify preventative maintenance.
| Phase | Three Phase |
|---|---|
| Manufacturer | Mersen |
| Series | UltraSafe™ US14 |
| Item number | S331147 |
| Catalogue number | US143MI |
| Product type | Modular cylindrical fuse holder |
| Fuse size | 14 × 51 mm |
| Number of poles | 3 |
| Rated current | Up to 50 A |
| Rated voltage AC UL | 800 V |
| Rated voltage DC UL | 1000 V |
| Frequency | 50 / 60 Hz |
| Visual indicator | Yes |
| Microswitch | Integrated |
| Terminal type | Pressure plate |
| Protection rating | IP20 |
| Mounting type | DIN rail mounting |
| EAN / UPC | 0782001311117 |
| HS Code | 85361050 |
| Country of Manufacture | Tunisia |
The Mersen S331147 is a three-pole modular fuse holder used to install and protect 14 × 51 mm cylindrical fuse links in industrial AC and DC electrical systems.
The Mersen catalogue reference for item number S331147 is US143MI.
Yes. It includes a visual blown-fuse indicator and an integrated microswitch for local and remote fuse-status indication.
The S331147 has UL rated voltages of up to 800 V AC and 1000 V DC.
It is designed for DIN rail mounting and uses pressure-plate terminals for secure conductor connections inside electrical panels and enclosures.
Mersen UltraSafe™ fuse holders are widely used by panel builders, OEMs and electrical engineers for dependable circuit protection, finger-safe maintenance and reliable fuse-status monitoring.
● Service Agreements
Credit Accounts
Our service agreements are built to support long term procurement relationships. By working closely with engineering teams and procurement departments, we help streamline purchasing processes while ensuring consistent access to critical components and sourcing support when it matters most.
● frequently asked questions
At Led Controls Ltd we help engineers source the right automation and control gear with confidence. below are quick answers to what we are asked most often.
We supply all leading manfacturers in our industry. we offer next day delivery on most poplour products.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
● latest blog
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...