MERSEN FUSE A 070 URD 31 TTI 0350 A070URD31TTI0350

MERSEN FUSE A 070 URD 31 TTI 0350 A070URD31TTI0350

High-speed aR characteristic fuse designed for semiconductor protection with a square ceramic body, striker indication, flush UNC thread ends, rated at 350A, 690VAC IEC and 700VAC UL.

SKU: D300475Alt SKU: A070UD31TTI350MPN: D300475
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List Price £130.39 ex VAT
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Why Choose the Mersen D300475 Protistor® High-Speed Semiconductor Fuse?

The Mersen D300475 is a genuine Protistor® Size 31 square body high-speed semiconductor fuse designed to provide ultra-fast protection for sensitive power electronic equipment. Manufactured as an aR class semiconductor fuse, it protects diodes, thyristors, IGBTs and other semiconductor devices operating on 690 V AC (IEC) and 700 V AC (UL) systems. This model has a 350 A current rating and features an integrated striker indicator with flush-end UNC threaded terminals.

Manufactured by Mersen, Catalogue Number A070UD31TTI350, the D300475 forms part of the internationally recognised Protistor® range. It features silver-plated contact surfaces, non-magnetic hardware and precision-manufactured fuse elements embedded in solidified silica sand, providing low let-through energy and outstanding semiconductor protection.

With a 200 kA AC breaking capacity, robust ceramic square body construction and flush-end threaded connections, the D300475 is ideally suited for industrial drives, converters, UPS systems, renewable energy equipment and other demanding power conversion applications requiring rapid fault interruption.

Key Advantages

  • Ultra-fast aR semiconductor protection fuse.
  • 350 A rated current.
  • 690 V AC IEC / 700 V AC UL voltage rating.
  • Integrated striker indicator for rapid fault indication.
  • Flush-end UNC threaded terminals for secure bolted installation.
  • 200 kA interrupting capacity.

Key Features

  • Mersen Protistor® Size 31 semiconductor fuse.
  • Catalogue number: A070UD31TTI350.
  • 350 A rated current.
  • 690 V AC IEC / 700 V AC UL.
  • aR operating class.
  • Integrated striker indication.
  • Flush-end UNC threaded terminals.
  • Square body bolted mounting.

Engineered for High-Speed Semiconductor Protection

Protistor® semiconductor fuses are engineered to minimise fault energy during overloads and short circuits, helping to protect expensive semiconductor devices while reducing equipment downtime. Their ultra-fast operating characteristics make them ideal for industrial power conversion equipment where fast fault clearance is essential.

The Mersen D300475 combines low I²t performance, high interrupting capacity and rugged construction to provide dependable protection in industrial automation, motor drives, UPS systems, renewable energy installations and power converters.

Typical Applications

  • Variable speed drives.
  • Industrial power converters.
  • UPS systems.
  • Renewable energy inverters.
  • Motor control centres.
  • Semiconductor protection circuits.

Technical Specifications

Item number D300475
Catalogue No A070UD31TTI350
Description Square Body High-Speed Fuse Protistor® Size 31 aR 690VAC IEC 700VAC UL 350A With Striker Flush ends UNC threads
EAN/UPC Code 3605340329049
Rated voltage AC UL 700 V
Rated voltage AC IEC 690 V
Ampere Rating 350 A
RoHS Compliant Yes
AC or DC AC
Speed/Characteristic aR
Fuse Size 31
Mounting Bolted
Clearing I2t At Rated Voltage 61000 A²s
Melting I2t 10300 A²s
AC Max I.R./Breaking Capacity I1: 200 kA
Indication System Yes
Indication System Type Striker
Connection/Terminal Material Silver-Plated Brass
Connection/Terminal Type Flush ends
Product Width 51 mm
Product Length 50.6 mm
Product Height 56.5 mm
Sell Pack Quantity 3 EA
Sell Pack Weight 1.155 kg
Sell Pack Width 85 mm
Sell Pack Length 168 mm
Sell Pack Height 65 mm
Product group Semiconductor Protection Fuses
Body/Insulating Material Ceramic
Product Weight 0.385 kg
Power Dissipation at Rated Current Value 67 W
HS Code 85361090
Country of Manufacture France
Fuse Type Semiconductor
Fuse Class aR
Voltage 690 V

Frequently Asked Questions

What is the Mersen D300475 used for?

The D300475 provides ultra-fast protection for power semiconductor devices including IGBTs, thyristors and diodes used in industrial power conversion equipment.

What is the current rating?

The fuse has a rated current of 350 A.

What voltage systems is it designed for?

It is rated for 690 V AC (IEC) and 700 V AC (UL) installations.

Does the D300475 include a blown fuse indicator?

Yes. It incorporates an integrated striker mechanism that can operate a compatible microswitch for remote indication.

What terminal style does this fuse use?

The D300475 uses flush-end UNC threaded terminals for secure bolted installation.

Trusted Worldwide for Semiconductor Protection

Mersen Protistor® semiconductor fuses are trusted by OEM manufacturers, panel builders and industrial engineers worldwide to protect valuable power electronic equipment in demanding industrial environments.

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