High-speed fuse with 900A rating, 1000VAC IEC and 1100VAC UL rated voltage, featuring a striker indication system and DIN 110 blade terminals for industrial semiconductor protection.
£312.12
The Mersen K300573 is a high-performance Protistor® square body semiconductor protection fuse engineered to provide ultra-fast protection for sensitive power electronic components. Designed for demanding industrial applications, this high-speed fuse safeguards IGBTs, thyristors, diodes, inverters and power conversion equipment against damaging short circuits while minimising energy let-through.
Part of the trusted Mersen Protistor® Size 73 aR series, the K300573 delivers exceptional reliability in industrial automation, renewable energy systems, motor drives and power conversion equipment. Its square body construction, silver-plated contacts and integrated striker indicator provide dependable performance whilst simplifying maintenance and fault detection.
With a 900 A current rating, 1000 V AC IEC / 1100 V AC UL voltage rating and 167 kA breaking capacity, the K300573 is designed for high-power semiconductor protection where fast fault clearance and dependable operation are essential.
High-speed semiconductor fuses are specifically designed to protect expensive power electronic devices from catastrophic damage caused by short circuits. Their ultra-fast operation limits fault energy before it reaches sensitive semiconductor components, helping minimise downtime and costly equipment repairs.
The Mersen Protistor® range is trusted throughout industry for protecting variable frequency drives, UPS systems, renewable energy converters, industrial power supplies and other high-power electronic installations where rapid fault interruption is essential.
| Current | 11 A |
|---|---|
| Item number | K300573 |
| Catalogue No | PC73UD10C900D1A |
| Description | Square Body High-Speed Fuse Protistor® Size 73 aR 1000VAC IEC 1100VAC UL 900A With Striker DIN 110 Blades |
| EAN/UPC Code | 3605340330502 |
| Rated voltage AC UL | 1100 V |
| Rated voltage AC IEC | 1000 V |
| Ampere Rating | 900 A |
| AC or DC | AC |
| Speed/Characteristic | aR |
| Fuse Size | 73 |
| Mounting | Bolted |
| Clearing I2t At Rated Voltage | 1440 kA²s |
| Melting I2t | 250 kA²s |
| AC Max I.R./Breaking Capacity | I1: 167 kA |
| Indication System | Yes |
| Indication System Type | Striker |
| Connection/Terminal Material | Silver-Plated Copper |
| Connection/Terminal Type | DIN 110 Blades |
| Product Width | 73 mm |
| Product Length | 133.4 mm |
| Product Height | 78.5 mm |
| Sell Pack Quantity | 3 EA |
| Sell Pack Weight | 3.36 kg |
| Sell Pack Width | 150 mm |
| Sell Pack Length | 250 mm |
| Sell Pack Height | 90 mm |
| Product group | Semiconductor Protection Fuses |
| Body/Insulating Material | Ceramic |
| Product Weight | 1.12 kg |
| Power Dissipation at Rated Current Value | 170 W |
| HS Code | 85361090 |
The K300573 is designed to provide ultra-fast protection for semiconductors including IGBTs, thyristors, diodes and other sensitive power electronic devices.
The Mersen K300573 has a 900 A current rating.
It is rated for 1000 V AC (IEC) and 1100 V AC (UL).
Yes. The fuse incorporates an integrated striker indication system for quick identification of fuse operation.
It is commonly installed in industrial drives, power converters, renewable energy systems, UPS equipment and other semiconductor protection applications.
Mersen Protistor® semiconductor fuses are relied upon worldwide by engineers and OEMs to deliver fast, dependable protection for high-value power electronic equipment operating in demanding industrial environments.
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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...