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MERSEN FUSE US143 US143
Mersen N331143 UltraSafe US143 three-pole modular fuse holder for 14×51 mm cylindrical fuse links, with pressure-plate terminals, IP20 protection and applicable ratings up to 800 V AC and 1000 V DC.
£28.93
Why Choose the Mersen N331143 UltraSafe™ US143 Fuse Holder?
The Mersen N331143, catalogue reference US143, is a robust UltraSafe™ modular fuse holder designed for 14×51 mm cylindrical fuse links. Its three-pole configuration provides coordinated fuse protection and circuit isolation for three-phase industrial electrical systems.
Part of the Mersen UltraSafe™ US14 range, the N331143 features a durable polyamide housing and finger-safe IP20 protection, including during fuse replacement. This helps protect personnel from accidental contact with live components while supporting safe and efficient panel maintenance.
The holder supports fuse currents up to 50 A and is rated for systems up to 800 V AC and 1,000 V DC under applicable UL ratings. Its pressure-plate terminals and DIN rail mounting format provide secure conductor connections and straightforward installation in control panels, machinery and power distribution equipment.
Key Advantages
- Designed for 14×51 mm cylindrical fuse links.
- Three-pole configuration for three-phase circuit protection.
- Supports fuse currents up to 50 A.
- Rated for systems up to 800 V AC and 1,000 V DC.
- Finger-safe IP20 protection, including during fuse replacement.
- Pressure-plate terminals provide secure conductor connections.
- DIN rail mounting simplifies installation in electrical panels.
- Durable polyamide construction offers excellent mechanical and thermal performance.
Key Features
- Mersen UltraSafe™ US14 series.
- Manufacturer item number N331143.
- Catalogue number US143.
- Accepts 14×51 mm cylindrical fuse links.
- Three-pole modular construction.
- 50 A conventional free-air thermal current with fuse links.
- 800 V AC UL rated voltage.
- 1,000 V DC UL rated voltage.
- Pressure-plate terminal connection.
- IP20 finger-safe protection.
- DIN rail mounting to EN 60715.
- Standard version without an integrated visual fuse indicator.
Safe Three-Phase Fuse Protection
The Mersen N331143 securely houses three 14×51 mm cylindrical fuse links, allowing correctly selected fuses to protect three-phase circuits against overload and short-circuit conditions. Its linked three-pole construction enables convenient operation and maintenance across all three protected phases.
The UltraSafe™ design maintains IP20 finger-safe protection during normal operation and fuse replacement. Combined with robust construction and secure pressure-plate terminals, this makes the holder well suited to demanding industrial AC and DC installations.
Typical Applications
- Three-phase industrial control panels.
- Motor and machinery protection circuits.
- Industrial power distribution equipment.
- Variable speed drive installations.
- Renewable energy and DC systems.
- OEM machinery and automation equipment.
- Electrical switchboards and enclosures.
Technical Specifications
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| Fuse Indication | None | |
|---|---|---|
| Phase | Three Phase | |
| Poles | 3-pole | |
| Device Type | Fuse base / holder | |
| Fuse Type | Cylindrical | |
| Fuse Size | 14x51 mm | |
| Voltage | 800 V | |
| Manufacturer | Mersen | |
| Series | UltraSafe™ US14 | |
| Item number | N331143 | |
| Catalogue number | US143 | |
| Product type | Modular cylindrical fuse holder | |
| Fuse size | 14 × 51 mm | |
| Number of poles | 3 | |
| Conventional free-air thermal current | 50 A | |
| Rated voltage AC UL | 800 V AC | |
| Rated voltage DC UL | 1,000 V DC | |
| Frequency | 50 / 60 Hz | |
| Terminal type | Pressure plate | |
| Fuse indication | No integrated visual indicator | |
| Protection rating | IP20 | |
| Mounting type | DIN rail mounting to EN 60715 | |
| Insulating body material | Polyamide | |
| Dimensions (H × W × D) | Approx. 110.8 × 79.5 × 76.5 mm | |
| Product weight | Approx. 0.43 kg | |
| EAN / UPC | 0782001311032 | |
| HS Code | 85361050 | |
| Country of Manufacture | Tunisia |
Frequently Asked Questions
What is the Mersen N331143 used for?
The Mersen N331143 is a three-pole modular fuse holder used with 14×51 mm cylindrical fuse links to protect three-phase industrial AC and DC electrical circuits.
Which fuse size fits the N331143?
The N331143 is designed specifically for 14×51 mm cylindrical fuse links.
What are the voltage and current ratings?
The holder supports fuse currents up to 50 A and has applicable UL voltage ratings of up to 800 V AC and 1,000 V DC.
Does the N331143 include a visual blown fuse indicator?
No. The US143 is the standard version without an integrated visual blown fuse indicator.
How is the Mersen N331143 installed?
It mounts onto a standard DIN rail in accordance with EN 60715 and uses pressure-plate terminals for secure conductor connection.
Trusted by Electrical Professionals Worldwide
Mersen UltraSafe™ fuse holders are trusted by panel builders, OEMs and electrical engineers for dependable circuit protection, finger-safe operation and reliable performance across demanding industrial installations.
