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MERSEN FUSE 12,5 URD 73 EF 0550 12,5URD73EF0550
High-speed fuse with aR characteristic, rated 550A, 1250VAC IEC and 1300VAC UL, featuring open slot blades with striker indication for semiconductor protection.
£147.92
Why Choose the Mersen A300633 High-Speed Semiconductor Fuse?
The Mersen A300633 is a heavy-duty Protistor® square-body high-speed semiconductor fuse designed to protect sensitive power electronic equipment against damaging short-circuit currents. Its ultra-fast operating characteristic helps safeguard IGBT modules, thyristors, diodes and other semiconductor components used in high-power industrial systems.
As part of the established Mersen Protistor® semiconductor fuse range, the A300633 combines rapid fault interruption with low let-through energy. This helps reduce thermal and mechanical stress on protected components, limiting secondary equipment damage and supporting improved system reliability.
With a rated current of 800 A and voltage ratings of 1250 V AC to IEC standards and 1300 V AC to UL standards, the Mersen A300633 is suited to high-capacity variable frequency drives, industrial converters, rectifiers, UPS equipment and power-control systems. Its robust square-body format and blade connections enable secure installation in compatible fuse holders and busbar assemblies.
Key Advantages
- Ultra-fast aR semiconductor fuse protection.
- 800 A rated current for high-power industrial equipment.
- 1250 V AC IEC and 1300 V AC UL voltage ratings.
- Low let-through energy helps protect costly semiconductor modules.
- Rapid short-circuit interruption reduces secondary equipment damage.
- Robust construction for demanding power-conversion applications.
Key Features
- Mersen Protistor® high-speed fuse series.
- Square-body semiconductor fuse.
- 800 A rated current.
- 1250 V AC IEC / 1300 V AC UL rated voltage.
- aR ultra-fast utilisation category.
- Heavy-duty blade terminal connections.
- Low let-through energy and controlled arc interruption.
- Engineered for short-circuit protection of power semiconductors.
Reliable Protection for High-Power Electronics
Power semiconductor devices can suffer permanent damage when exposed to excessive short-circuit energy for even a brief period. High-speed fuses such as the Mersen A300633 use precision-engineered fuse elements to interrupt fault currents rapidly and limit the amount of energy transferred into the protected circuit.
This controlled fault-clearing performance makes the A300633 suitable for installations where equipment availability, semiconductor protection and operational reliability are essential. Correct fuse coordination can help protect expensive power modules, minimise secondary damage and reduce maintenance-related downtime.
Typical Applications
- High-power variable frequency drives.
- Industrial inverters and converters.
- Rectifier and thyristor assemblies.
- Uninterruptible power supply systems.
- High-capacity motor drives and soft starters.
- Industrial power supplies and automation equipment.
Technical Specifications
Tick the specs you need, then view products that match.
| Fuse Indication | Striker | |
|---|---|---|
| Fuse Type | Semiconductor | |
| Fuse Class | aR | |
| Voltage | 1250 V | |
| Item number | A300633 | |
| Catalogue No | PC73UD13C550EF | |
| Description | Square Body High-Speed Fuse Protistor® Size 73 aR 1250VAC IEC 1300VAC UL 550A With Striker Open Slot Blades | |
| EAN/UPC Code | 3605340331332 | |
| Rated voltage AC UL | 1300 V | |
| Rated voltage AC IEC | 1250 V | |
| Ampere Rating | 550 A | |
| AC or DC | AC | |
| Speed/Characteristic | aR | |
| Fuse Size | 73 | |
| Mounting | Bolted | |
| Clearing I2t At Rated Voltage | 465 kA²s | |
| Melting I2t | 57 kA²s | |
| AC Max I.R./Breaking Capacity | I1: 126 kA | |
| Indication System | Yes | |
| Indication System Type | Striker | |
| Connection/Terminal Material | Silver-Plated Copper | |
| Connection/Terminal Type | Open Slot Blades | |
| Product Width | 73 mm | |
| Product Length | 149.4 mm | |
| Product Height | 78.5 mm | |
| Sell Pack Quantity | 1 EA | |
| Sell Pack Weight | 1.11 kg | |
| Sell Pack Width | 110 mm | |
| Sell Pack Length | 180 mm | |
| Sell Pack Height | 80 mm | |
| Product group | Semiconductor Protection Fuses | |
| Body/Insulating Material | Ceramic | |
| Product Weight | 1.11 kg | |
| Power Dissipation at Rated Current Value | 120 W | |
| HS Code | 85351000 |
Frequently Asked Questions
What is the Mersen A300633 used for?
The Mersen A300633 provides high-speed short-circuit protection for semiconductor devices installed in industrial drives, converters, rectifiers and other high-power electronic equipment.
What is the rated current of the Mersen A300633?
The Mersen A300633 has a rated current of 800 A.
What voltage is the A300633 rated for?
The fuse is rated for up to 1250 V AC under IEC specifications and 1300 V AC under UL specifications.
What does the aR fuse classification mean?
The aR classification identifies a partial-range fuse with an ultra-fast operating characteristic designed specifically for short-circuit protection of semiconductor devices.
Does the A300633 provide overload protection?
An aR semiconductor fuse is primarily intended for short-circuit protection. Suitable overload protection should be provided separately by the equipment’s monitoring, control or protective system.
Trusted by Power Electronics Professionals
Mersen Protistor® fuses are specified by industrial engineers, system integrators and equipment manufacturers for dependable high-speed protection of critical semiconductor and power-conversion equipment.
